BlueCore ® ADK Audio Sink Application User Guide Issue 3 see pages 9, 18-20, 26,27 © Cambridge Silicon Radio Limited 2013-2014 Page 1 of 42 CS-236868-UGP3 www.csr.com Document History Revision Date History 1 15 FEB 13 Original publication of this document 2 15 DEC 13 Updated for ADK 3 and to the new CSR style 3 27 JAN 14 Minor editorial corrections Contacts www.csr.com sales@csr.com www.csrsupport.com product.compliance@csr.com comments@csr.com Trademarks, Patents and Licences Unless otherwise stated, words and logos marked with ™ or ® are trademarks registered or owned by CSR plc and/or its affiliates. Bluetooth® and the Bluetooth logos are trademarks owned by Bluetooth SIG, Inc. and licensed to CSR. Other products, services and names used in this document may have been trademarked by their respective owners. The publication of this information does not imply that any licence is granted under any patent or other rights owned by CSR plc or its affiliates. CSR reserves the right to make technical changes to its products as part of its development programme. While every care has been taken to ensure the accuracy of the contents of this document, CSR cannot accept responsibility for any errors. Life Support Policy and Use in Safety-critical Compliance CSR’s products are not authorised for use in life-support or safety-critical applications. Use in such applications is done at the sole discretion of the customer. CSR will not warrant the use of its devices in such applications. Performance and Conformance Refer to www.csrsupport.com for compliance and conformance to standards information. © Cambridge Silicon Radio Limited 2013-2014 Page 2 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide General information Information on this product Customer support for this product More detail on compliance and standards Help with this document Contents © Cambridge Silicon Radio Limited 2013-2014 Page 3 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide Document History ......................................................................................................................................................... 2 Contacts........................................................................................................................................................................ 2 Trademarks, Patents and Licences .............................................................................................................................. 2 Life Support Policy and Use in Safety-critical Compliance............................................................................................ 2 Performance and Conformance .................................................................................................................................... 2 Contents ....................................................................................................................................................................... 3 Tables, Figures and Equations ..................................................................................................................................... 4 1. Introduction ............................................................................................................................................................ 5 1.1. Hardware ........................................................................................................................................................ 5 2. Getting Started....................................................................................................................................................... 6 2.1. To Flash the Audio Sink Application onto Suitable Hardware ......................................................................... 6 2.2. Making a Bluetooth Connection with Another Device ..................................................................................... 7 3. To Set Up the xIDE Project Environment ............................................................................................................... 8 3.1. Libraries Used by the Audio Sink Application ................................................................................................. 8 3.2. To Enable Extra A2DP Codecs .................................................................................................................... 10 3.3. To Enable Debug Output .............................................................................................................................. 10 4. Peer Device Support............................................................................................................................................ 11 4.1. ShareMe ....................................................................................................................................................... 11 4.2. True Wireless Stereo (TWS)......................................................................................................................... 12 4.3. To Enable Peer Device Support ................................................................................................................... 12 4.4. Configuration ................................................................................................................................................ 14 4.5. Pairing Devices............................................................................................................................................. 15 4.6. Audio Relay Operation ................................................................................................................................. 15 4.7. Ending a Peer Session ................................................................................................................................. 15 4.8. TWS Audio Routing ...................................................................................................................................... 16 5. Soundbar Configuration ....................................................................................................................................... 17 6. AUDIO Configuration ........................................................................................................................................... 18 6.1. Input Sources ............................................................................................................................................... 18 6.2. SPDIF Input .................................................................................................................................................. 19 6.3. Output Sources............................................................................................................................................. 20 7. Audio Routing – Music Applications..................................................................................................................... 27 7.1. Low Latency Applications ............................................................................................................................. 27 7.2. Silence Detection.......................................................................................................................................... 27 7.3. SPDIF Configuration..................................................................................................................................... 27 8. Volume Control .................................................................................................................................................... 28 8.1. DAC Volume Control .................................................................................................................................... 28 8.2. Digital Volume Control .................................................................................................................................. 28 8.3. Hybrid Volume Control ................................................................................................................................. 29 9. Input Manager ..................................................................................................................................................... 30 9.1. Feature Overview ......................................................................................................................................... 30 9.2. Input Events.................................................................................................................................................. 30 9.3. Timers .......................................................................................................................................................... 31 9.4. To Configure the Input Manager ................................................................................................................... 31 10. Bluetooth Smart Input Monitor.......................................................................................................................... 32 10.1. HID Over GATT Profile ............................................................................................................................. 32 10.2. Overview ................................................................................................................................................... 32 10.3. Profile Dependencies ................................................................................................................................ 32 10.4. Roles ......................................................................................................................................................... 32 Tables, Figures and Equations Table 1.1: PS Keys to Read Using PSTool ................................................................................................................... 5 Table 3.1: Audio Sink Application Libraries................................................................................................................. 10 Table 4.1: DSP Application Build Configurations ........................................................................................................ 13 Table 4.2: TWS Pairing Modes ................................................................................................................................... 14 Table 4.3: Default Peer Session Initiation Events Button Mapping ............................................................................. 15 Table 4.4: Default Peer Session End Event Button Mapping ...................................................................................... 15 Table 4.5: TWS Audio Routing ................................................................................................................................... 16 Table 6.1: Configuration Parameters .......................................................................................................................... 20 Table 6.2: PSKEY_USR_36 Format ........................................................................................................................... 23 Table 12.1: Audio Sink Application States .................................................................................................................. 40 Figure 6.1: SPDIF Function Block Diagram ................................................................................................................ 19 © Cambridge Silicon Radio Limited 2013-2014 Page 4 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide 10.5. Feature Overview ...................................................................................................................................... 33 10.6. Bluetooth Smart Input Monitor Events ...................................................................................................... 33 10.7. User Events .............................................................................................................................................. 33 10.8. System Events .......................................................................................................................................... 34 10.9. Pairing and Connection Management ....................................................................................................... 34 10.10. To Set Up the HID Device ......................................................................................................................... 35 10.11. Using the Bluetooth Smart Input Monitor .................................................................................................. 36 10.12. Bluetooth Smart Input Monitor Configuration ............................................................................................ 37 11. Infra-red Input Monitor...................................................................................................................................... 38 11.1. Feature Overview ...................................................................................................................................... 38 11.2. Infra-red User Events ................................................................................................................................ 38 11.3. Infra-red System Events ........................................................................................................................... 38 11.4. Supported Infra-red Consumer Protocols.................................................................................................. 38 11.5. Infra-Red Transmissions ........................................................................................................................... 38 11.6. Infra-red Learning Mode ........................................................................................................................... 39 11.7. Configuring the Infra-red Input Monitor ..................................................................................................... 39 12. Audio Sink Application States .......................................................................................................................... 40 Document References ................................................................................................................................................ 41 Terms and Definitions ................................................................................................................................................. 41 1. Introduction This document describes how to use the Audio Sink application included in this ADK. The Audio Sink application provides a basis for developing Bluetooth enabled: Headsets Soundbars Speakers The application runs as a Bluetooth Audio Sink that supports the following profiles: HSP v1.1 HFP v1.6 A2DP v1.3 AVRCP v1.5 MAP v1.0 PBAP v1.0 Additionally it supports the Bluetooth Smart profile: Battery Level Service This document should be used in conjunction with the document ADK Sink Application Configuration and ADK Subwoofer User Guide. 1.1. Hardware The document describes the Audio Sink application in this ADK running on the CSR Bluetooth Headset example design boards CNS10001v4 (CSR8670) and DEV-PC-1645 (BlueCore5-MultiMedia). Note: BlueCore5-Multimedia firmware only supports an external flash of 70 ns or faster. A DEV-PC-1309 interface board and suitable SPI interface, such as a CSR 1324 USB-SPI converter, is required to program and debug the device. 1.1.1. Backing Up the Development Board Before flashing the application onto the hardware CSR recommends clearing all the PS Keys from the development board. This places the board into a known good state. All tools are available in the [ADK]\tools\bin sub directory. Alternatively, tools with a GUI (e.g. PSTool, BlueFlash) can be accessed from the Windows’ Start menu under ADK\Tools. Note: Read the values in the PS Keys listed in Table 1.1 using PSTool and record the values so that they can be restored later: BlueCore5-Multimedia CSR8670 PSKEY_BDADDR PSKEY_ANA_FTRIM PSKEY_CHARGER_CURRENT PSKEY_CHARGER_TRIM PSKEY_BDADDR PSKEY_ANA_FTRIM_OFFSET PSKEY_CHARGER_CURRENT Table 1.1: PS Keys to Read Using PSTool © Cambridge Silicon Radio Limited 2013-2014 Page 5 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide To clear the board’s PS Keys using BlueFlash: 1. Click Stop Processor and select Flash Erase. 2. Check the Erase Persistent Store box and then select OK. 3. Exit BlueFlash. The application is ready to be flashed from the xIDE development environment onto the development board. 2. Getting Started 2.1. To Flash the Audio Sink Application onto Suitable Hardware Connect the interface board to the development board and attach the SPI interface and USB charger. 2. Attach suitable headphones and microphone to the sockets on the development board. 3. Open the xIDE development environment from the ADK program folder. 4. Select Open Workspace from the Project menu and select the sink application from the apps subdirectory. 5. By default the application is setup to run on CSR8670 hardware, to change hardware or audio mode, see section 2. 6. Make sure the Transport is set correctly. Choose Debug > Transport and select the required Debug Transport. 7. Use PSTool to merge the relevant PS Keys onto the device, for basic operation, for: CNS10001v4 development board: Use sink_system_csr8670.psr and sink_config_10001v4_stereo.psr. Note: The following example configurations for use with the CNS10001v4 are available: Car kit Mono headset Soundbar Stereo headset Wired/USB headset. 8. Select Run (F5) from the Debug menu. 9. The application is now running on the hardware. Note: The Audio Sink application can also run independently of the xIDE environment by selecting Stop from the Debug menu when the Audio Sink application is running then resetting the hardware. © Cambridge Silicon Radio Limited 2013-2014 Page 6 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide 1. 2.2. Making a Bluetooth Connection with Another Device 2.2.1. To Pair and Connect the Audio Sink Application to an AG Device 1. Turn on the Audio Sink application by pressing and holding the VREG button, if the Audio Sink application has not been paired before it will automatically enter pairing mode and be connectable and discoverable. 2. Discover the Audio Sink application with the AG an initiate pairing. If a pin code is requested enter 0000. 3. The Audio Sink application is now paired with the AG. 2.2.2. To Clear the Audio Sink Application Paired Device List © Cambridge Silicon Radio Limited 2013-2014 Page 7 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide In some cases, it is necessary to clear the PDL for successful connection or reconnection. This can be configured to a button press using the Audio Sink Configuration Tool. 3. To Set Up the xIDE Project Environment Audio Sink application project configurations are provided for Headset and Soundbar use cases on CSR8670 and BlueCore5-Multimedia, these can be selected from the drop down box in the xIDE tool bar. Compile time options can then be selected from the Audio Sink application project properties and Enabled or Disabled as required. Note: Including project options that are unsupported by the hardware you are using may produce the error: Application uses trapsets which firmware doesn't support. 3.1. Libraries Used by the Audio Sink Application Many libraries are used by the Audio Sink VM application; they are specified in the VM Project Properties. Some libraries have different build variants either to enable a different configuration or to exclude unused code to save flash space. Including libraries that are unused produces a harmless build warning. Many libraries have debug variants that can be enabled by adding _debug. Note: Some library variants that are not commonly used are disabled from the build to optimise compile time. To enable these variants edit the VARIANTS file for the required library and recompile. Table 3.1 lists all libraries that the Audio Sink application uses, the default variant is highlighted in bold. Library Available Variants Notes avrcp avrcp, avrcp_controller, avrcp_target, avrcp_debug Variants disable controller/target parts respectively. power power, power_debug connection connection, connection _l2cap, connection_rfcomm, connection_rfcomm_no_inquiry, connection_debug, connection _no_ble, connection _debug_no_ble Variants to disable L2CAP, RFCOMM and BLE. bdaddr bdaddr - hfp hfp, hfp_min_cfm, hfp_debug, hfp_min_cfm_debug min_cfm variant sends region region - service service - codec codec, codec_nowolfson The nowolfson variant excludes Wolfson codec support. © Cambridge Silicon Radio Limited 2013-2014 - the minimum required confirmation messages to the application Page 8 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide When running on BlueCore5-MultiMedia Hardware the Execution Mode should be left on the setting Hardware Default or set to Native mode, Assisted Native mode is not available with this platform. The Sink application does not fit in the memory available with VM mode firmware for BlueCore5-MultiMedia. Only Assisted Native should be selected when using CSR8670. Library Available Variants Notes csr_tone_plugin csr_tone_plugin, csr_tone_plugin_debug - audio audio, audio_tts, audio_vp, audio_tts_debug, audio_vp_debug, audio_asr, audio_asr_vp, audio, audio_asr_vp_debug Variants enable support for: csr_cvc_common_pl ugin csr_cvc_common_plugin, csr_cvc_common_plugin_all, csr_cvc_common_plugin_all_debug, All variants support all CVC types and stereo mode csr_voice_prompts _plugin csr_voice_prompts_plugin, csr_voice_prompts_plugin_file_only, - Text To Speech, Voice Prompts Speech Recognition csr_a2dp_decoder_ common_plugin csr_a2dp_decoder_common_plugin_debug, a2dp a2dp, a2dp_debug, a2dp_multi_slot, a2dp_multi_slot_debug, a2dp_atrac, a2dp_sbc_only csr_a2dp_decoder_common_plugin_stereo, csr_a2dp_decoder_common_plugin_stereo_debug, csr_a2dp_decoder_common_plugin _stereo_bidir, csr_a2dp_decoder_common_plugin _stereo_bidir_debug, csr_a2dp_decoder_common_plugin _stereo_bidir_wbs, csr_a2dp_decoder_common_plugin_stereo_bidir_w bs_debug, Variants to enable aptX back channel modes. Variant to support atrac and SBC only. Note: The Multi_slot variant uses multiple memory slots for internal storage. csr_common_exampl e_plugin csr_common_example_plugin - obex obex, obex_debug, obex_v2 - sdp_parse sdp_parse - md5 md5 - usb_device_class usb_device_class, usb_device_class_no_mass_storage, usb_device_class - spp_common spp_common, spp_common_debug - spps spps, spps_debug - sppc sppc, sppc_debug - pblock pblock, pblock_debug - © Cambridge Silicon Radio Limited 2013-2014 Page 9 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide csr_voice_prompts_plugin_file_only_dsp, csr_voice_prompts_plugin_file_only_dsp_debug Available Variants Notes audio_plugin_comm on audio_plugin_common - csr_dut_audio_plu gin csr_dut_audio_plugin, csr_dut_audio_plugin_debug - csr_speech_recogn ition_plugin csr_speech_recognition_plugin, csr_speech_recognition_plugin_debug - pio_common pio_common, pio_common_debug - pbapc pbapc, pbapc_debug, pbapc_debug_print - mapc mapc, mapc_debug - gatt gatt, gatt_debug - batt_rep batt_rep, batt_rep_debug - Table 3.1: Audio Sink Application Libraries 3.2. To Enable Extra A2DP Codecs By default the ADK is configured to use SBC for AD2P audio connections. Optionally it can be configured to use MP3, AAC or aptX decoders: 1. Ensure that the relevant add-on package has been installed onto the ADK. 2. Add the Decoder application to the project workspace: 3. From the Project menu select Insert Project into Workspace and select the relevant project from the directory: 4. Edit the sink.mak file to ensure that the decoders .kap file is copied into the Audio Sink application image directory. The relevant code is provided commented out in the sink.mak file. If the .kap file is not in the Audio Sink image directory the code crash when attempting to load the DSP decoder. 5. In the Audio Sink project settings enable the Extra Codec feature. 6. Run the project (F5), the new decoder should be built and installed in the image. <ADK>\kalimba\apps\a2dp_sink 3.3. To Enable Debug Output Adding the DEBUG_PRINT_ENABLED define symbol enables debug output. This can be set in the sink_debug.h file. Debug for particular files can be enabled and disabled by editing the relevant #define(s) in sink_debug.h. Note: When debug is enabled in the application or libraries the application does not run without a debugger attached. © Cambridge Silicon Radio Limited 2013-2014 Page 10 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide Library 4. Peer Device Support The ADK has a feature that allows two ADK based devices to connect to each other and relay A2DP based audio. The two connected ADK devices are known as Peer devices and connect in a “Peer” session, for the duration of this connection. The Peer device initiating a Peer session establishes both an A2DP Signalling channel and an AVRCP Control channel to the other Peer device. A Peer device acts as both an A2DP Source and Sink. It operates as an A2DP Source to relay audio received from another input source. It acts as an A2DP Sink to render audio received from another Peer or input source. The A2DP codecs supported, for audio relay between two Peer devices, are: SBC MP3 AAC AptX. Note: The low latency Faststream and Aptx-LL codecs are not supported. A Peer device acts as an AVRCP Controller and Target for both Category 1 and Category 2 commands. A Peer device relaying audio to another Peer behaves as a Category 1 Target to allow the other Peer to control stream state between the two Peers. A Peer device receiving relayed audio behaves as a Category 1 Controller, as per normal ADK operation. Both Peers also operate as Category 2 devices to allow volume to be adjusted. SCO based audio connections are not supported between Peer devices, so it is not possible to relay HFP call audio between Peer devices. The ADK provides two modes of Peer Device support: 1. ShareMe 2. True Wireless Stereo (TWS) Note: It is possible to support both Peer Device modes on a single device. 4.1. ShareMe This mode of Peer device operation allows audio received from an A2DP Source to be relayed to another Peer device that also supports ShareMe mode. The same audio is rendered by both devices but rendering is not synchronised between the two Peer devices. The audio input source, when operating in Audio Sharing mode, is restricted to A2DP based sources e.g. a mobile phone. © Cambridge Silicon Radio Limited 2013-2014 Page 11 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide 4.2. True Wireless Stereo (TWS) This mode of Peer Device operation allows audio received from an A2DP, USB or Wired Source to be relayed to another Peer device that also supports TWS mode. The same audio is rendered by both devices and is synchronised between the two Peer devices. When operating in TWS mode the audio input source is restricted to an A2DP based source, e.g. Mobile phone USB audio Analogue wired audio. Note: SPDIF and FM input sources are not supported. Features include: Tightly synchronised audio playback Synchronised volume control Device specific trim gain when operating as a TWS device Flexible audio routing TWS is designed to ensure tight audio playback synchronisation between two peer devices. It does this using timestamps embedded in the relayed audio data, and a combination of synchronization delays and rate matching to ensure synchronous playback. In addition to synchronized audio playback, TWS provides synchronized volume control on the two peer devices, taking advantage of the digital volume control framework in Music Manager to allow greater control of the timing of volume changes. 4.3. To Enable Peer Device Support Support for Peer Device functionality needs to be enabled in the VM Sink application project settings as well as the appropriate DSP Decoder applications, see sections 4.3.1 and 0. 4.3.1. VM Under the VM Sink application project settings, select the f Peer Device operation mode supported from the Peer Device Support dropdown. The options available are: Disabled ShareMe TWS ShareMe and TWS These are used to enable/disable support in the VM application as required. © Cambridge Silicon Radio Limited 2013-2014 Page 12 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide When operating in TWS mode, vendor specific AVRCP commands are used to assist operation for relaying current user EQ settings etc. 4.3.2. DSP Each DSP Decoder application that is used by a device must have the appropriate level of Peer device support enabled. The VM application assumes that any of the DSP applications used for rendering audio during a Peer session have the correct level of support enabled. The SBC, MP3 and AptX DSP Decoder applications supports: ShareMe or ShareMe and TWS. The AAC DSP Decoder application supports TWS functionality. Note: The SBC Decoder also supports USB and Analogue wired input sources. Table 4.1 describes the options available for enabling/disabling the four DSP Decoder applications. Configuration Description Release No Peer Device support ShareMe ShareMe supported only (not supported by AAC Decoder) TWS Both ShareMe and TWS supported TWS_WIRED_MODE ShareMe and TWS with additional USB and Analogue wired input support (only supported by SBC Decoder) Table 4.1: DSP Application Build Configurations © Cambridge Silicon Radio Limited 2013-2014 Page 13 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide AAC is not natively supported by the ShareMe feature. Instead the VM application closes any AAC stream and re-opens it using one of the other available codecs to relay audio. 4.4. Configuration 4.4.1. General 4.4.1.1. Device ID The Device ID record presented by a device can be used to allow/deny connection to another Peer device. The first three records of a remote Peer’s Device ID i.e. the Vendor ID Source, Vendor ID and Product ID are matched against the local Peer’s Device ID. If a match is found then connection is allowed. 4.4.1.2. Single Device Operation When operating in a Peer session, AVRCP commands issued on the Slave and can be routed, via the Master, to the AV Source. This allows control of media streaming from the Slave device as well as the Master. 4.4.2. ShareMe 4.4.2.1. UUID A 128-bit UUID can be used to advertise support for the ShareMe feature. This can be used in conjunction with the Device ID record if required. A match of the remote Peer’s ShareMe UUID against the local Peer’s ShareMe UUID determines if ShareMe functionality is enabled. 4.4.3. True Wireless Stereo 4.4.3.1. UUID A 128-bit UUID can be used to advertise support for the TWS feature. This can be used in conjunction with the Device ID record if required. A match of the remote Peer’s TWS UUID against the local Peer’s TWS UUID determines if TWS functionality is enabled. 4.4.3.2. Pairing Mode ShareMe pairings are always deemed temporary. However, TWS devices can have different levels of pairing dependant on the required application. Table 4.2 describes the pairing options available for TWS devices. Pairing Type Description Temporary No pairing information is retained when the Peer session ends. However, attempts to recover from a link loss situation are made. Normal Pairing information is stored in the normal way. An entry is used within the device’s PDL. This entry can drop of the end of the list if too many pairings with other devices are made. Permanent Pairing information is retained, even after a clear of the PDL. It can only be overwritten by pairing another TWS device. The paired device always appears as the first device in the PDL. Table 4.2: TWS Pairing Modes © Cambridge Silicon Radio Limited 2013-2014 Page 14 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide When a call is taken on either Peer Device, audio streaming is suspended on both devices. It is only possible to answer a call on the Peer device that is actually receiving the call. 4.4.3.3. SBC Encoder Params When using a USB or Analogue wired input with a TWS device, audio is encoded as SBC for relay to a Peer device. The various parameters that set up the encoder are specified here. See the A2DP Specification for details. 4.4.3.4. Device Trim Volume When operating in a TWS Peer session, the relative volume levels of each Peer device can be adjusted using the Device Trim mechanism. The parameters in this section allow the default Device Trim gains to be defined along with the range and resolution of adjustment. 4.5. Pairing Devices Table 4.3 shows the standard key mappings for the two peer events. These can be changed using the Sink Configuration tool. Event Button Mapping Duration EventPeerSessionInquire VREG + PIO10 Very Long (2.5 secs) EventPeerSessionConnDisc VREG + PIO12 Very Long (2.5 secs) Table 4.3: Default Peer Session Initiation Events Button Mapping 4.6. Audio Relay Operation Either Peer device may be connected to an AV Source. When streaming is initiated from one AV Source, an A2DP media channel is established between the two Peer devices and used to relay the received audio to the other device. When audio is rendered, the level of synchronisation between both Peer devices is determined by the mode of operation. ShareMe makes no attempt to synchronise the audio. For True Wireless, the audio between the two Peer devices is synchronised to within a few samples. If both Peer devices are connected to separate AV Sources, then both may relay audio to their corresponding Peer. However, audio relay can only occur in one direction at one time. The Peer device that is currently relaying audio from its connected AV Source to another Peer is known as a Master Peer device. The Peer device receiving relayed audio is known as a Slave Peer device. The Master/Slave Peer status changes depending on which device is relaying audio. 4.7. Ending a Peer Session To terminate the connection between two Peer devices, without affecting the connection to any other device, use the EventPeerSessionEnd event. Table 4.4 shows the standard key mapping for this event. This can be changed using the Headset Configuration tool. Event Button Mapping Duration EventPeerSessionEnd VREG + PIO10 or VREG + PIO12 Very Long (2.5 secs) Table 4.4: Default Peer Session End Event Button Mapping © Cambridge Silicon Radio Limited 2013-2014 Page 15 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide A different mechanism is used to pair Peer devices and establish a Peer session. One Peer device must be placed into Peer Inquiry mode and the other Peer device must be placed into Peer Discoverable mode. This is done by generating the application events EventPeerSessionInquire and EventPeerSessionConnDisc, respectively. 4.8. TWS Audio Routing TWS offers a flexible audio routing mechanism to meet the specific needs of a wireless audio system. Default routing options are specified in the PS Keys and all routings can be tied to user events to allow dynamic control of channel assignments. The audio routing changes are also synchronised and under the control of the master TWS device. Mono Output(one DAC) Stereo Left ,Right Left+Right Left Left , Left Left Right Right, Right Right Downmix Left+Right, Left+Right Left+Right BlueCore ADK Audio Sink Application User Guide Stereo Output(both DACs) Table 4.5: TWS Audio Routing The audio routing configuration can be set using the Sink Configuration Tool. © Cambridge Silicon Radio Limited 2013-2014 Page 16 of 42 CS-236868-UGP3 www.csr.com 5. Soundbar Configuration The Sink application has configuration aimed at Soundbars using CSR8670. In addition to the usual features of the Sink application this enables manual selection of audio sources (see events in ADK Sink Configuration) and optional use of a wireless Subwoofer device, see ADK Subwoofer User Guide. To configure this, load the Sink application as described in section 2.1 but merge the .psr file sink_config_10001v4_soundbar.psr and select the Soundbar project configuration type from the xIDE menu bar. BlueCore ADK Audio Sink Application User Guide © Cambridge Silicon Radio Limited 2013-2014 Page 17 of 42 CS-236868-UGP3 www.csr.com 6. AUDIO Configuration 6.1. Input Sources The Sink application accepts audio input from a variety of different sources including: Analogue wired input USB wired input SPDIF wired input Bluetooth audio inputs as well as FM receive The default PSR configuration files for the Headset build configures the application to accept the following input sources: Bluetooth SCO and A2DP Analogue wired USB Wired The default PSR configuration files for the Soundbar build configures the application to accept the following input sources: Bluetooth SCO and A2DP Analogue wired USB wired SPDIF wired or optical The Headset and Soundbar builds differ in the way they handle the audio routing, for a Headset build the audio is routed automatically when an audio source becomes available, audio is routed based on a priority system, headset audio priorities are: 1. Bluetooth Audio 2. USB audio 3. Analogue wired audio The priorities cannot be changed without modifications to the audio routing code in the sink_audio_routing.c file, if required the order of the function calls checking for available audio sources can be re-ordered to suit a particular application. Audio routing for the Soundbar is a manual process, audio sources are routed as a direct result of a user generated event tied to a particular button press, the default .psr file comes with the capacitive touch sensors pre-configured to select the individual audio sources, there is no priority based switching available, any source can be selected at any time. The default configuration for use on a CSR8670 development board is: Cap 0 sensor: Select FM audio source Cap 1 sensor: Select Analogue wired source Cap 2 sensor: Select USB wired source Cap 3 sensor: Select AG1 Bluetooth source Cap 4 sensor: Select AG2 Bluetooth source Cap 5 sensor: Select SPDIF wired source Input Source selections can be configured using the Sink Configuration Tool. © Cambridge Silicon Radio Limited 2013-2014 Page 18 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide 6.2. SPDIF Input The SPDIF wire digital audio input supports all the features that are available to the analogue input types including: Music enhancement User EQ Configurable volume control High quality voice prompts Audio routing Subwoofer connections; Note: TrueWireless is not available for SPDIF input. The SPDIF input interface supports all SPDIF standard sample rates: 48 KHz 44.1 KHz 32 KHz The sample rate is automatically detected and any transient is smooth and glitch-free. It also supports detection of compressed digital audio defined by the IEC 61937 standard. CSR’s ADK 3.0 support s the Dolby Digital AC-3 format which can be used to connect the output of DVD players or game consoles. Contact CSR to get the Dolbycertified AC-3 decoder and instructions on how to enable Dolby Digital in ADK 3.0. (Optional) S/PDIF Input IEC-61937 Dolby Digital AC-3 Decoder for Compressed Audio Enhancement User EQ, Bass Manager, Volume control, etc To Speakers (Analogue, I2S, or S/PDIF) To Wireless Subwoofer Figure 6.1: SPDIF Function Block Diagram To build and include Contact CSR input support: 1. Open sink application in xIDE. 2. Insert Kalimba spdif_sink project into the sink project. The spdif_sink project is located in: 3. The default setting for the project includes Subwoofer support and plays only PCM uncompressed audio, Go to the spdif_sink Project Properties and configure the project if you want to change it. 4. Make sure in the sink.mak that the SPDIF is included in the build image: ADK_FOLDER\kalimba\apps\a2dp_sink image/spdif_sink/spdif_sink.kap : $(mkdir) image/spdif_sink $(copyfile) ..\..\kalimba\apps\a2dp_sink\image\spdif_sink\spdif_sink.kap $@ image.fs : image/spdif_sink/spdif_sink.kap Note: In the default configuration for Soundbar application, the CAP-SENSE-5 sensor has been defined to select and route SPDIF input audio. © Cambridge Silicon Radio Limited 2013-2014 Page 19 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide There are hardware reference designs for both coaxial (phono) and optical (TOSLINK) SPDIF connections. 6.2.1. SPDIF-specific Configuration Table 6.1 lists the configuration parameters which can be set using the Sink Configuration tool. Feature Default Range Target Latency 40 20 to 150 (ms) Supported Data types 0 - Table 6.1: Configuration Parameters Description of Configuration Parameters: Target Latency: This is the amount of required latency needed by the user. Note: The target latency is used to synchronise the audio and video by adjusting the required latency in the audio path. The range of the value for target latency is 20 ms to 80 ms. When playing compressed Dolby Digital audio the maximum latency can be increased up to 150 ms. Supported Data Types: By default the application only plays uncompressed stereo digital audio, i.e. PCM audio, coming from the SPDIF input interface. To support Dolby Digital AC-3 compressed audio the corresponding check box needs to be ticked. When receiving unsupported compressed audio from S/PDIF input interface, the output will be muted. 6.3. Output Sources Both the Headset and Soundbar applications can outputt t audio using DAC, I2S or SPDIF. The default configuration .psr files for both the Headset and Soundbar are configured to use the DAC output using the digital volume control scheme, detailed in section 8.2. 6.3.1. I2S Output Soundbar and Headset applications can be configured to use I2S to output audio data to an external audio DAC/amplifier.configuration of the I2S interface using the Sink Configuration Tool allows a range of output clock rates to be chosen along with the creation of customised I2C control instructions. An external amplifier typically requires an I2C interface to configure registers within the device for channel configuration and volume control. The PS key settings allow I2C instructions to be created that are sent to the external device at audio connect, disconnect and volume control events. The I2S functionality is enabled using the Sink Configuration Tool to change the AudioOutput Type parameter in the Audio Routing tab, by default this is set to DAC, changing this to I2S enables the I2S output for all the DSP audio applications. Two PS Keys are used to configure I2S functionality: For Sink/Soundbar use: 1. PSKEY_USR_35 : To define Initialisation data and raw data structures 2. PKSEY_USR_36: To set raw data forI2C commands and volume commands Configuration of the I2S interface can be performed using the Sink Configuration Tool, for reference the PS Keys the tool creates are: © Cambridge Silicon Radio Limited 2013-2014 Page 20 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide The Target Latency is defined by the delay between the time an audio sample reaches the IC until it is rendered at the output audio interface. This is the latency that occurs within the IC and does not include any latency that might occur in any external digital speaker. PSKEY_USR_35 Format: e.g. 0001 0010 2806 021e 0000 0008 0000 00ff bb80 bb80 0100” where: PluginType Master or Slave Operation Left or Right Justified I2S Justified data delay by 1 bit Bits per sample Usr data key length No of initI2c commands No of i2c volume commands Volume commands offset Type Uint8 Uint8 Uint4 Uint4 Uint8 Uint8 uint8 Uint8 uint8 Range 0-1 0–1 0-1 0-1 0 -255 0 – 255 0-255 0 – 255 0-255 Default Value 1 1 0 1 16 0 0 0 0 Shutdown commands offset Volume no of bits Volume range max Volume range min Music resampling frequency Voice resampling frequency uint8 uint8 Uint16 Uint16 Uint16 Uint16 Uint16 Uint16 Range 0-255 0-255 0-65535 0–65535 0-65535 0 -65535 0–65535 0-65536 Default Value 0 0 16 15 0 48000 48000 256 Scaling factor No of i2c Shutdown commands Type Master clock Label Words 5 to 11: Description of PSKEY_USR_35: Plugin Type: Specifies which I2S plugin to use: 0 = User defined via PSKEY_USR_35 and PSKEY_USR _36, 1 = SSM_2518 CSR I2S development board 2 = Customer developed plugin © Cambridge Silicon Radio Limited 2013-2014 Page 21 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide Label Words 1 to 4: Master or Slave Operation: Specifies master or slave operation: 0 = slave, 1 = master. Left or right Justified I2S: Select left justified or I2s data: 0 = left justified data format, 1 = right justified data format. Justified data delay by 1 bit: The I2S data can be delayed by 1 bit: 0 = no delay of I2S data output, 1 = 1 bit delay of I2Sdata output. Bits per sample: Specifies the number of bits in each audio sample, defaults to 16. USR data key length: Specifies the length of raw data commands in PSKEY_USR_37 in words. No of init I2c commands: Specifies how many I2C initialisation commands are specified in PSKEY_USR_37, the data key. No of i2c volume commands: Specifies the number of individual I2C volume commands that will be sent to the I2S capable device every time a volume change is made. Volume commands offset: Specifies the offset in words of the first I2C volume command in the data PSKEY_USR_37. No of i2c shutdown commands: Specifies the number of individual I2C commands that will be sent to the I2S capable device every time the device is shut down, i.e. close of SCO or a2dp media stream. Shutdown commands offset: Specifies the offset in words of the first I2C volume command in the data PSKEY_USR_37. Volume no of bits: Specifies the number of bits of the volume setting in the I2C command, default is 8 bits. Volume range max: Specifies the maximum volume value that will be sent to the I2S device to indicate maximum output level. Volume range min: Specifies the minimum volume value that will be sent to the I2S device to indicate minimum output level. Music resampling frequency: Specifies whether the music (A2DP codecs, USB, wired audio) output rate needs to be resampled to a fixed rate, a value of 0 indicates no resampling is performed, otherwise specify the required output frequency, e.g. 48000. Voice resampling frequency: Specifies whether the voice (CVC, tones, voice prompts) output rate needs to be resampled to a fixed rate, a value of 0 indicates no resampling is performed, otherwise specify the required output frequency, e.g. 48000. Master clock Scaling factor: Specifies the scaling factor for the I2S master clock. © Cambridge Silicon Radio Limited 2013-2014 Page 22 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide PSKEY_USR_36 format: This key contains the raw data of the I2C initialisation and volume commands. Table 6.2 describes the format of PSKEY_USR_36. Volume level offset in packet Type Uint16 Uint16 Range 0-255 Default Value 0 Packet length Volume level offset in packet Uint16[packet length] Uint8 0 –255 0-255 0 0 Packet data Packet data etc Uint8 Uint8[packet length] .... 0-255 0 –255 0-255 .... 0 0 0 .... Table 6.2: PSKEY_USR_36 Format The raw data is effectively an array of packets, the initialisation command packets must be first in the array followed by the volume command packets. Description of PSKEY_USR_36 Packet length: This is the length of the packet in words, data bytes are actually packed as words, e.g. for an I2C initialisation command packet of: 0x68, 0x00, 0x81 Raw data is: 0068 0000 0081 with a packet length of 3. Volume level offset in packet: This word is only applicable to data packets that set the volume/audio level output of the left and right channels, its value is ignored for non-volume related packets. For example. for an I2C volume packet of: I2C ID, set vol command, volume level 0x68, 0x05, 0x?? The volume level offset value would be 1, since the first byte is always the I2C Device ID, the first data byte [0] is the 0x05 (set volume command), the second data byte [1] is the actual volume level. The volume level is not necessarily only 8-bits, its size is configured in the initialisation PS Key, if the volume level size is larger than 1 byte then the volume level offset indicates the start of the data to be replaced with the current sink or subwoofer volume level. Packet data:The packet data is an array of i2C command bytes whose length is specified by the Packet_length value, e.g. for an I2C initialisation command of: I2C ID, set sample rate, automatic sample rate control 0x68, 0x01, 0x01 The complete packet and header information would comprise of five bytes and would be: Packet length, volume offset, I2C ID, I2C data 0x03, 0x00, 0x68, 0x01, 0x01 © Cambridge Silicon Radio Limited 2013-2014 Page 23 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide Label Packet length 6.3.1.1. To Create an I2S/I2C Configuration PS Key This section gives an example that describes how to create an I2S/I2C Configuration PS Key. For this example the following is assumed: The configuration will use plugin type of 0 – fully configurable I2S and I2C interface control by PS Key. 2. The I2S interface on the sink/sub will run in master mode. 3. The clock multiplier will be 256x. 4. The sink/sub will use the DSP apps to resample all audio to always output at 48 Khz 5. The I2S device will support configuration by I2C commands 6. The I2S device will support volume control of the left and right channels separately by I2C commands and will use 8 bits for the volume level setting, its scaling will be 255 to 0 representing minimum to maximum volume respectively. 7. The I2C initialisation commands are: 8. 0x68, 0x00, 0x81 – clock selection 0x68, 0x00, 0x04 – reset control 0x68, 0x01, 0x01 – automatic sample rate control 0x68, 0x02, 0x02 – set sample rate 0x68, 0x03, 0x00 – Set external clock control 0x68, 0x07, 0x00 – Set mute to off The I2C volume commands are: 0x68, 0x05, 0x00 – set left channel volume 0x68, 0x06, 0x00 – set right channel volume Example: 1. Create the raw I2C commands data. This comprises of all of the initialisation commands followed by the volume commands. 0x68,0x00,0x81 0x68, 0x00, 0x04 0x68, 0x01, 0x01 0x68, 0x02,0x02 0x68, 0x03,0x00 0x68, 0x07, 0x00 0x68, 0x05,0x00 0x68,0x06,0x00 2. Add the packet length and volume level offset values: 0x03, 0x00, 0x03, 0x00, 0x03, 0x00, 0x03, 0x00, 0x03, 0x00, 0x03, 0x00, 0x03, 0x01, offset byte 0x03, 0x01, 3. 0x68, 0x68, 0x68, 0x68, 0x68, 0x68, 0x68, 0x00, 0x81 - initialisation commands 0x00, 0x04 0x01, 0x01 0x02,0x02 0x03,0x00 0x07, 0x00 0x05,0x00 - Volume commands, include volume level 0x68,0x06,0x00 Convert the bytes into words for writing to the PS Key: 0003 0000 0068 0000 0081 0003 0000 0068 0000 0004 0003 0000 0068 0001 0001 0003 0000 0068 0002 0002 0003 0000 0068 0003 0000 0003 0000 0068 0007 0000 0003 0001 0068 0005 0000 0003 0001 0068 0006 0000 © Cambridge Silicon Radio Limited 2013-2014 Page 24 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide 1. 4. Create the PS Key initialisation: 4.1. Set the plugin type, for this example a fully configurable PS Key: 0x00 4.2. Set I2S master mode of operation: 0x01 4.3. Set I2S data format: 0x00 4.4. - False indicates I2S data format Set the number of bits per sample: 0x10 4.5. - 16-bits per sample of I2S audio data Set the complete length of the raw data PS Key: 4.6. - Length of PSKEY_USR_37 Set the number of separate I2C initialisation commands, NOT including the volume commands: 0x06 4.7. - Six I2C initialisation commands Set the volume of volume I2C commands: 0x02 4.8. - Two I2C volume commands, one for left channel one for right channel Set the offset (in words) of the start of the first volume I2C packet: 0x1e 4.9. - Offset in words of first volume command in PSKEY_USR_37 Set the number of bits of volume level to replace in the I2C volume commands: 0x0008 4.10. Set the volume maximum value accepted by the I2C command: 0x0000 4.11. - resample to 48000 Hz Set voice resampling frequency, for cvc and voice prompts audio sources 0xbb80 4.14. - Volume is inverted and scaled appropriately Set music resampling frequency, for A2DP, wired and USB audio sources: 0xbb80 4.13. - volume is effectively inverted for this device Set the volume minimum value accepted by the I2C command: 0x00ff 4.12. - Volume setting is 8-bits for this device - resample to 48000 Hz Set the master clock scaling factor 0x0100 - I2S clock scaling factor to 256 Create the PS Key for the initialisation of the I2S and raw data commands using the settings above: PSKEY_USR_35 0001 0010 2806 021e 0000 0008 0000 00ff bb80 bb80 0100 6. Combine this with the raw data PS Key created in step 3: PSKEY_USR_36 0003 0000 0068 0000 0081 0003 0000 0068 0000 0004 0003 0000 0068 0001 0001 0003 0000 0068 0002 0002 0003 0000 0068 0003 0000 0003 0000 0068 0007 0000 0003 0001 0068 0005 0000 0003 0001 0068 0006 0000 The I2C command data can be entered using the Sink Configuration Tool I2S Command Data option. © Cambridge Silicon Radio Limited 2013-2014 Page 25 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide 0x28 5. - True indicates master operation 6.3.2. SPDIF Output The DSP applications can be configured to output audio output using SPDIF connection. This is done using the Sink Configuration tool set the audio output type to SPDIF. BlueCore ADK Audio Sink Application User Guide © Cambridge Silicon Radio Limited 2013-2014 Page 26 of 42 CS-236868-UGP3 www.csr.com Audio Routing – Music Applications 7. Both the Headset and Soundbar applications have a PS Key that configures the audio routing capabilities of the device, PSKEY_USR_37, this key can be configured with the Sink Configuration Tool and allows control of both the input and output routing options as well as other optional settings. 7.1. Low Latency Applications The sink workspace contains music DSP applications for: SBC decoder SPDIF decoder Faststream decoder Low Latency Faststream and Aptx decoder with 1-mic CVC back channel support Low Latency Faststream and Aptx decoder with 2-mic CVC back channel support By default the standard Faststream decoder is used when the Faststream codec is negotiated, this decoder can be replaced at runtime with a low latency version with CVC back channel support for gaming applications by enabling either of the following configuration options: 1. Use 1-mic Back Channel 2. Use 2-mic Back Channel The low latency DSP applications support Faststream or APTX Low latency codec types and provide 1 or 2-mic CVC back channel functionality. 7.2. Silence Detection The Headset or Soundbar music DSP applications support silence detection, this can be configured in the Audio Routing tab of the Sink Configuration Tool and can be used to power down an external amplifier to save power etc. 7.3. SPDIF Configuration The SPDIF functionality can be configured to support PCM or PCM with AC3 support, the AC3 functionality is not shipped with the ADK by default and must be obtained directly from CSR. © Cambridge Silicon Radio Limited 2013-2014 Page 27 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide 8. Volume Control Both the Headset and Soundbar support three types of volume control: 1. DAC Volume Control 2. Digital Volume Control 3. Hybrid Volume Control The Sink Configuration Tool is used to configure the three different types of volume control using the Volume Configuration tab. 8.1. DAC Volume Control 8.2. Digital Volume Control This mode of volume control is only available to DSP music applications, CVC voice applications continue to use DAC volume control. The digital volume control works by setting the chip DAC to a fixed level and applying digital attenuation to the audio signal within the DSP itself. This method of volume control is able to provide a much higher granularity of the volume changes as well as increased range and an overall lower output level than that achieved using DAC control only. The digital attenuation gives a usable range of 0 dB max down to -80dB minimum output level. The Sink Configuration tool can be used to configure the digital volume control other settings: Volume Control Type: Number of Steps from Min to Max: Default of 32 but may be configured to any number of steps DAC Gain: Set to digital The DAC gain is fixed when using digital control, a value of 15 gives 0 dB output level Left Channel Trim: Default of 0 but a trim can be applied to the left channel only in dB units Right Channel Trim: Volume steps for Knee value 1 and 2: The volume level increase/decrease curve can be adjusted to have a non-linear relationship using two knee values, the volume level in dB is calculated as a linear function between the min/max knee 1 and knee2 points. Volume level for knee value 1 and 2: Default of 0 but a trim can be applied to the right channel only in dB units Specifies the dB audio output levels for the knee points of the steps versus audio output level curve. Maximum and Minimum Gain in dB: These values set the actual dB audio output level at Max and Min volume steps. Note: USB and AVRCP volume levels are scaled appropriately to give the same overall range as that configured but depending upon the volume range and number of steps chosen there may be some rounding errors with the USB or AVRCP volume level changes, keeping to a multiple of the AVRCP volume levels minimises these errors, i.e. CSR recommends using 128, 64, 32 or 16 steps. © Cambridge Silicon Radio Limited 2013-2014 Page 28 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide This legacy mode of volume control is available to both CVC voice and Music applications. The on-chip DACs are used to control the level of the audio output signals, these have a range of 16 steps giving a minimum volume level of -45 dB up to a maximum volume level of 0 dB. The step volume levels are set in the Sink Configuration Tool. 8.3. Hybrid Volume Control To give the best signal to noise ratio volume control it is necessary to use the Hybrid Volume Control mechanism, this is a combination of DAC and DSP volume control. The configuration is the same as for the digital volume control with the exception of setting the volume control type to hybrid. Hybrid volume control works by using the DAC control to give steps of 3 dB in combination with the digital DSP control to give increased resolution of 0 to 3 dB. As with the digital volume control the resolution can be whatever is required for the product but attention should be paid to the step size to smooth operation with USB and AVRCP volume level changes. BlueCore ADK Audio Sink Application User Guide © Cambridge Silicon Radio Limited 2013-2014 Page 29 of 42 CS-236868-UGP3 www.csr.com 9. Input Manager 9.1. Feature Overview The Input Manager for the Soundbar application is responsible for managing events received from all Input Monitor Tasks. There are two parts to the Input Monitor: 1. Bluetooth Smart Input Monitor 2. Infra-red Input Monitor The Input Manager decides which input events are used to generate user events that the Soundbar application then processes.it gives a clear layered structure to managing input events of various types. Figure 8.1 outlines the design structure of the Input Manager: 9.2. Input Events The Input Manager task generates user events based on input events, these input events can be considered as virtual buttons, the supported list of input events is: InputEventDown: The input(s) have been pressed down. InputEventVShortRelease: InputEventShortTimer: InputEventShortRelease: The input(s) have been released before the short timer fires. The short timer fires whilst the input(s) are still pressed down. The input(s) have been released after the short timer has fired, but before the long timer has fired. InputEventLongTimer: The long timer fires while the input(s) are still pressed down. © Cambridge Silicon Radio Limited 2013-2014 Page 30 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide Figure 8.1: Design Structure of the Input Manager InputEventLongRelease: InputEventVLongTimer: The input(s) have been released after the long timer has fired, but before the very long timer has fired. The very long timer fires while the input(s) are still pressed down. InputEventVLongRelease The input(s) have been released after the very long timer has fired, but before the very very long timer has fired. InputEventVVLongTimer: InputEventVVLongRelease: InputEventRepeatTimer: The input(s) have been released after the very very long timer has fired The repeat timer has fired while the input is still pressed down. Note: The repeat timer continues to fire every configured (ms) duration until the input(s) are released. 9.3. Timers The Input Manager is the only place where timers used by input monitors are configured, each input monitor must inherit the configured timers from the input manager so all inputs are based on the same user interaction. For ADK 3.0, the buttons are not controlled by the Input Manager; they are managed by the Button Manager. 9.4. To Configure the Input Manager The Input Manager uses a lookup table to convert input events to user events, this lookup table is configured using PS Keys, see the ADK Sink Application Configuration User Guide for further details on all configuration options for this feature. © Cambridge Silicon Radio Limited 2013-2014 Page 31 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide The very very long timer fires while the input(s) are still pressed down. 10. Bluetooth Smart Input Monitor 10.1. HID Over GATT Profile 10.2. Overview The HID Over GATT Profile (HOGP) defines the procedures and features to be used by Bluetooth Smart HID Devices using GATT and Bluetooth HID Hosts using GATT. This profile is an adaptation of the USB HID specification to operate over a Bluetooth low energy wireless link. This profile only operates over a Low energy transport. 10.3. Profile Dependencies Generic Attribute Profile (GATT) Battery Service Device Information Service Scan Parameters Profile 10.4. Roles The profile defines three roles: 1. HID Device: The HID Device shall be a GATT server. 2. Boot Host: The Boot Host shall be a GATT client. 3. Report Host: The Report Host shall be a GATT client. HID Host refers to both Host roles, Boot Host and Report Host. A Report Host: Required to support a HID Parser and be able to handle arbitrary formats for data transfers (known as Reports). A Boot Host : Not required to support a HID Parser as all data transfers (Reports) for Boot Protocol Mode are of predefined length and format. 10.4.1. Concurrent Role Limitations and Restrictions A Boot Host shall not concurrently be a Report Host. A Report Host shall not concurrently be a Boot Host. There are no concurrency limitations on either HID Host roles from also being a HID Device. 10.4.2. Limitations and Restrictions The HID Device shall use the GAP Peripheral role. The Boot Host shall use the GAP Central role. The Report Host shall use the GAP Central role. 10.4.3. Multiple Service Instances Multiple service instances shall not be supported for the following services: Device Information Service Scan Parameters Service Multiple service instances of the HID Service may be supported to allow implementers to define composite HID Devices whose combined functions require more than 512 octets of data to describe. Multiple service instances of the Battery Service may be supported. © Cambridge Silicon Radio Limited 2013-2014 Page 32 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide This profile requires the: Multiple service instances of the following may be supported, but are not considered a part of this profile: Any Service other than HID Service, Device Information Service, or Scan Parameters Service. 10.5. Feature Overview The Bluetooth Smart HOGP feature within the CSR Soundbar application has been implemented such that the device adopts the Report Host Role as defined by the HOGP specification. The feature runs as a standalone task that has been named BLE Input Monitor, it manages connections with HID Devices acting as remote controllers that are able of sending HID commands to the Soundbar device. 10.6. Bluetooth Smart Input Monitor Events 10.7. User Events The following list describes each of the user events that are supported by the BLE Input Monitor: EventUsrBleEnablePairingMode: EventUsrBleDisablePairingMode: EventUsrBleEnablePtsTestMode: EventUsrBleDisablePtsTestMode: EventUsrBleConnectStoredRemote: EventUsrBleDisconnectStoredRemote: Used to enable BLE Pairing Mode. Used to disable BLE Pairing Mode. Used to enable BLE PTS Test Mode. Used to disable BLE PTS Test Mode. Used to initiate a connection request to the stored remote. Used to initiate a disconnection request to the stored remote. EventUsrBlePtsModeNext: Used to progress to the next stage when running in PTS Test Mode. EventUsrBleChangeWriteModePriority: EventUsrBleEnterSuspendMode: EventUsrBleExitSuspendMode: EventUsrBleEnableNotifications: EventUsrBleDisableNotifications: Used to change the write mode priority. Used to put all connected remote controllers into suspend mode. Used to take all connected remote controllers out of suspend mode. Used to enable notifications for all connected remote controllers. Used to disable notifications for all connected remote controllers. © Cambridge Silicon Radio Limited 2013-2014 Page 33 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide The BLE Input Monitor feature relies on a set of user events (that can be configured using the Sink Configuration tool) to control the task and its mode of operation. This section describes user and system events that are used by the BLE Input Manager. 10.8. System Events The following list describes each of the system events that are supported by the BLE Input Monitor: EventSysBleRemotePairingTimeout: EventSysBleRemotePairingSuccess: This event is used to indicate when a Bluetooth Smart HID Device has successfully paired with the Soundbar device. EventSysBleRemotePairingFailed This event is used to indicate when the Bluetooth Smart Pairing Timeout timer fires. This event is used to indicate when a Bluetooth Smart HID Device has unsuccessfully paired with the Soundbar device. EventSysBleRemoteConnected This event is used to indicate when a Bluetooth Smart HID Device has connected with the Soundbar device 10.9. Pairing and Connection Management The Soundbar application manages Bluetooth Smart connections with HID Devices allowing them to transfer HID commands to the Soundbar device, this section describes how the Soundbar application managers these connections. 10.9.1. Supporting Multiple HID Devices The BLE Input Monitor is capable of managing multiple concurrent connections with HID Devices, the number of concurrent connections is limited depending on the configuration setup, this section will discuss multiple concurrent connections in more detail. To configure the maximum number of supported concurrent connections, see ADK Sink Configuration User Guide. 10.9.2. Pairing with a HID Device The Bluetooth Smart Input Monitor uses a pairing mode for pairing with new HID Devices, this pairing mode is controlled by both user events and a pairing mode timeout. 10.9.2.1. Enabling Bluetooth Smart Pairing Mode The user event EventUsrBleEnablePairingMode is used to enable the Bluetooth Smart Pairing Mode, when the pairing mode has been enabled, any nearby (and unpaired) HID Device that is advertising is paired and connected. Advertisements from unpaired HID Devices are ignored at all other times. Pairing success with a particular HID Device cannot be guaranteed if there are multiple unpaired HID Devices advertising at the time Bluetooth Smart Pairing Mode is enabled. It is based on a first come first serve basis, where the first advertisement from an unpaired device is the device that is paired and connected to(if possible). When a nearby HID Device has been successfully paired, Bluetooth Smart Pairing Mode is automatically disabled. Pairing mode is not enabled if the maximum number of concurrent connected devices is already equal to the maximum supported. 10.9.2.2. Explicitly Disabling Bluetooth Smart Pairing Mode The user event EventUsrBleDisablePairingMode is used to disable the Bluetooth Smart Pairing Mode, if required the user can generate this event to disable the Bluetooth Smart Pairing Mode at any point while Bluetooth Smart Pairing Mode is enabled. © Cambridge Silicon Radio Limited 2013-2014 Page 34 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide 10.9.2.3. Connections with Paired Devices While Bluetooth Smart Pairing Mode is Enabled While the Bluetooth Smart Pairing Mode is enabled, paired HID Devices are still able to connect with the Soundbar. If a paired device connects while Pairing Mode is active, the pairing mode is only automatically disabled if the number of connections is equal to the maximum supported, see the ADK Sink Configuration User Guide for further details on configuring this option. 10.9.3. To Establish Connections with Paired HID Devices 10.9.3.1. Connection Establishment Procedure HID Devices must be paired before they can be connected; paired HID Devices are able to connect and disconnect as they like while they are still paired with the Soundbar device. A nearby HID Device can send out Bluetooth Smart advertisements that are picked by the Soundbar device; when an advertisement is picked up the Soundbar checks whether the advertisement is coming from a paired device, if it is, it sends a connection request to the HID Device. The BD/EDR state for the Soundbar is irrelevant to the Bluetooth Smart Input Monitor when managing connections with HID Devices, they may connect and disconnect whenever they require. Any paired HID Device can freely connect with the Soundbar while the number of c connected HID Devices is less than the maximum number allowed. When the number of concurrently connected HID Devices reaches the maximum allowed, the Soundbar device ignores advertisements from all other paired devices. 10.9.3.2. To Connect the Stored Device The Soundbar allows the Bluetooth address of a HID Device to be stored with the configuration data. The Soundbar can issue a connection request to this HID Device whenever the user requires by use of the EventUsrBleConnectStoredRemote user event. If the HID Device is not available for connection, the connection timesout and the device is not connected. 10.10. To Set Up the HID Device When the Soundbar has connected with a HID Device, even though the connection has been setup and the devices are connected, the devices are not ready to communicate. This section describes the processes to setup the HID Device so it is ready to communicate with the Soundbar. 10.10.1. Service Discovery The Soundbar must discover the services that are supported by the HID Device. Since the HID Device can update its GATT Database at any time while it is not connected; it is not safe for the Soundbar to store the GATT service handles between connections. Therefore, after each reconnection, the Soundbar must always discover which services are supported by the HID Device. 10.10.2. Included Services When all services of the HID Device have been discovered, the Soundbar must then find any included services that the HID Device has setup. 10.10.3. Characteristic Discovery When all the #includes (if any) have been discovered, the Soundbar must discover all the characteristics for each service and store the GATT handles. © Cambridge Silicon Radio Limited 2013-2014 Page 35 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide The Soundbar device must have enabled Bluetooth Smart scans to read advertisements being broadcast from nearby HID Devices, the Soundbar enables and disables Bluetooth Smart Scans automatically. While the number of connections to HID Devices is less than the maximum configured, Bluetooth Smart Scans are enabled to allow other paired HID Devices to connect. 10.10.4. Descriptor Discovery When all the characteristics for each service have been discovered, the Soundbar must discover all descriptors for each characteristic that the HID Device has setup. The Descriptors are used to describe each characteristic. Ssome characteristics may have multiple descriptors to describe what features are or are not supported. 10.10.5. Processing the Characteristics When all the descriptors have been discovered, the Soundbar has a clear picture of the GATT Data Base that has been setup for the HID Device. At this stage, the Soundbar knows what characteristics are supported, but does not know enough information about each one to make decisions on how they can be used. When the properties for each characteristic have been read and stored, the Soundbar finds Report characteristics defined by the HID Device. Report characteristics are used to transfer data from the HID Device to the Soundbar. In most cases they are used to notify when buttons are pressed on the HID Device. The Soundbar is only interested in Input Reports so must discover which input reports exist on the HID Device and enable notifications for each one that supports notifications. Enabling notifications allows the HID Device to know that the Soundbar wants to be notified of important events for that characteristic. When all notifications have been setup, the Soundbar needs to discover whether or not the HID device supports Suspend Mode, which is used to inform the HID Device when the Soundbar enters/exits a low power mode. The Soundbar searches for all HID Control Point characteristics defined on the HID device and stores a list of the ones that support Suspend Mode. When this is complete, the HID Device is considered fully connected. It is at this point that the system event EventSysBleRemoteConnected is used to indicate that an RC has connected and is ready for use. 10.10.6. Enabling and Disabling Notifications Manually If required, the Soundbar application allows the user to enable or disable notifications from all connected HID Devices. While notifications are disabled, the HID Device never sends notifications signalling that an event has occurred on the HID Device. This is not something is used often, but could be used to enable/disable the feature without having to disconnect all connected remote controllers. Note: This feature exists to pass PTS tests for the HID Over GATT Profile. 10.10.7. Enabling and Disabling Suspend Mode Manually If required, the Soundbar application allows the user to enable or disable Suspend Mode for all connected HID Devices. Note: This feature exists to pass PTS tests for the HID Over GATT Profile. 10.11. Using the Bluetooth Smart Input Monitor When a HID Device has connected with the Soundbar application, the Bluetooth Smart Input Monitor is responsible for managing this HOGP connection. Incoming report notifications from the HID Device that contain HID code(s) are converted to Input IDs (based on the configured lookup table), the Bluetooth Smart Input Monitor task then sends messages to the Input Manager task to indicate when a button on the HID Device has been pressed. If a HID code is received that does not exist within the configured lookup table, the Bluetooth Smart Input Monitor ignores the event. © Cambridge Silicon Radio Limited 2013-2014 Page 36 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide Each characteristic must have a characteristic declaration descriptor that declares the characteristic, part of this descriptor includes the properties of the characteristic and reading the properties lets the Soundbar know a list of operations it can perform on the characteristic, so the first stage is to find each characteristic declaration descriptor, read the descriptor and store the properties for each discovered characteristic. While the button is pressed and held, the Bluetooth Smart Input Monitor task continues to send input event messages to the input monitor (depending on the timer configuration), informing the input manager of the duration of the button press, when the button is released, the Bluetooth Smart Input Monitor sends an event to the input manager indicating that the button has been released. It is the responsibility of the input manager to listen to these input events from the Bluetooth Smart Input Monitor and generate user events the Soundbar application can process. 10.12. Bluetooth Smart Input Monitor Configuration See the ADK Sink Configuration User Guide for a complete guide on configuration for the Bluetooth Smart Input Monitor. BlueCore ADK Audio Sink Application User Guide © Cambridge Silicon Radio Limited 2013-2014 Page 37 of 42 CS-236868-UGP3 www.csr.com 11. Infra-red Input Monitor 11.1. Feature Overview The Infra-Red Input Monitor for the Soundbar application is responsible for managing events received from Infra-red remote controllers. Infra-red events are converted to input events and sent to the Input Manager so they can be processed. This section describes how to use the Infra-red Input Monitor task. Note: The Infra-red Input Monitor does not support Multiple Infra-red buttons being pressed. 11.2. Infra-red User Events EventUsrStartIRLearningMode: Event to enable Infra-red learning mode. EventUsrStopIRLearningMode: EventUsrClearIRCodes: Event to disable Infra-red learning mode. Event to clear all Infra-red codes learnt by the Soundbar. 11.3. Infra-red System Events The Infra-red Input Monitor has a set of system events that are used to notify of events that have occurred, the list of events is: EventSysIRCodeLearnSuccess: Inform that a new Infra-red event has been learnt. EventSysIRCodeLearnFail: EventSysIRLearningModeTimeout: EventSysIRLearningModeReminder: Indicates that a new Infra-red event failed to be learnt. Indicates that the Infra-red Learning mode has timed out and is now disabled. Repeat reminder to indicate that Learning mode is still active. 11.4. Supported Infra-red Consumer Protocols ADK 3.0 supports two Infra-red protocols: 1. NEC 2. RC5 However, ADK 3.0 cannot support both protocols simultaneously, i.e. cannot communicate with both an NEC and an RC5 remote simultaneously. 11.5. Infra-Red Transmissions Infra-red remote controllers transmit Infra-red data that is received by the Soundbar, these transmissions have two bits of information that identify the event being transmitted: 1. Address 2. IR Code The address is an 8-bit data type that contains the remote controller’s address. The IR Code is an 8 bit-data type that contains the IR Code the controller is transmitting. © Cambridge Silicon Radio Limited 2013-2014 Page 38 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide The Infra-red Input Monitor can be controlled through user events. The list of user events used to configure and setup the Infra-red input monitor are: When the Soundbar application is notified of an Infra-red transmission, the address and code must match an entry in either the default configuration lookup table or a special lookup table containing learnt Infra-red codes. 11.6. Infra-red Learning Mode The Infra-red Learning mode is a feature whereby new Infra-red codes can be learnt by the Soundbar application. When a new code has been learnt, it is added to a lookup table so that when the learnt code is received, the associated user event can be generated. To learn a new code Learning mode must be enabled, using the EventUsrStartIRLearningMode event. The process of learning a new code is with Learning mode enabled, a pre-configured (or pre-learnt) code from a remote controller is pressed, then the unknown button (the button to learn) is pressed on the second remote controller. Events can be learnt from any connected input whose input is monitored by an Input Monitor task that sends input events to the Input Manager. Infra-red learning mode can be explicitly disabled at any time by generating the EventUsrStopIRLearningMode user event. 11.7. Configuring the Infra-red Input Monitor See the ADK Sink Configuration User Guide for a complete guide on configuration for the Infra-red Input Monitor feature. © Cambridge Silicon Radio Limited 2013-2014 Page 39 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide Note: 12. Audio Sink Application States The Audio Sink application defines the application states in the source file sink_states.h. Each Bluetooth profile has its own state machine. Table 12.1 describes the main states used by the application. Description deviceLimbo The Audio Sink application is logically off but physically on – limbo. deviceConnectable The Audio Sink application is connectable - page scanning deviceConnDiscoverable The Audio Sink application is connectable and discoverable - page and inquiry scanning. deviceConnected The Audio Sink application is connected to an AG. deviceOutgoingCallEstablish The connected AG has an outgoing call in progress. deviceIncomingCallEstablish The connected AG has an incoming call in progress. deviceActiveCallSCO The connected AG has an active call in progress and the audio is in the Audio Sink application. deviceTestMode The Audio Sink application is in test mode. deviceThreeWayCallWaiting The connected AG has an active call and a second incoming call. deviceThreeWayCallOnHold The connected AG has an active call and a second call on hold. deviceThreeWayMulticall The connected AG has more than one active call. deviceIncomingCallOnHold The connected AG has an incoming call on hold. deviceActiveCallNoSCO The connected AG has an active call and the audio is in the handset. deviceA2DPStreaming The Audio Sink application is streaming A2DP audio. deviceLowBattery Low battery state, does not actually change to this state but will be used for independent low battery LED warning. Table 12.1: Audio Sink Application States © Cambridge Silicon Radio Limited 2013-2014 Page 40 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide State Document References Document Reference ADK Subwoofer User Guide CS-237475-UG ADK Sink Application Configuration User Guide CS-306726-UG Terms and Definitions Advanced Audio Distribution Profile AAC Advanced Audio Coding ADC Analogue-to-Digital Converter ADK Audio or Application Development Kit AG Audio Gateway AVRCP Audio/Video Remote Control Profile BLE Bluetooth low energy, now Bluetooth Smart BlueCore® Group term for CSR’s range of Bluetooth wireless technology chips Bluetooth® Set of technologies providing audio and data transfer over short-range radio connections Bluetooth Smart Previously BLE CSR Cambridge Silicon Radio DIP Device ID Profile DSP Digital Signal Processor e.g. exempli gratia, for example GAIA Generic Application Interface Architecture HFP Handsfree Profile i.e. Id est, that is IC Integrated Circuit ID Identifier LED Light Emitting Diode MAP Message Access Profile PBAP Phone Book Access Profile PC Personal Computer PDL Paired Device List PIO Programmable Input/Output © Cambridge Silicon Radio Limited 2013-2014 Page 41 of 42 CS-236868-UGP3 www.csr.com BlueCore ADK Audio Sink Application User Guide A2DP PS Key Persistent Store Key RSSI Received Signal Strength Indication SBC Sub-band Coding SCO Synchronous Connection-Oriented SIG (Bluetooth) Special Interest Group SPI Serial Peripheral Interface USB Universal Serial Bus xIDE CSR’s Integrated Development Environment BlueCore ADK Audio Sink Application User Guide © Cambridge Silicon Radio Limited 2013-2014 Page 42 of 42 CS-236868-UGP3 www.csr.com
