Programming Classes
 Monday: Sensor reading over TinyOS
 Wednesday: Message sending and receiving between
TelosB motes
 Friday: Android programming
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Course Project
 Check-out your devices
 TelosB motes: you can check-out your second mote from
the TA next week
 Smartphone: send me the type and quantity of phones
you need, then check-out from the TA
 Customized devices: purchase online, get money back at
the end of semester
 Start acting NOW!
 Next milestone
 Project midterm presentation & demo: 10/7 & 10/9
ECE 455 Embedded System Design
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ECE 455/555
Embedded System Design
TinyOS: Sensor Reading
Wei Gao
Fall 2015
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Recall about TinyOS
 Component model
 An application consists of
Application
Component
D
wired components
Component
A
 Application = graph of
components
 Components are wired
through interfaces
 Wiring specified by
configurations
configuration
 Configuration can be
hierarchical
Component
C
Component
B
Component
F
Component
E
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configuration
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Interfaces
 List of exposed events and commands
 Like ordinary C function declarations
Interface Receive
{
event message_t * Receive(message_t * msg, void * payload, uint8_t len);
command void * getPayload(message_t * msg, uint8_t * len);
command uint8_t payloadLength(message_t * msg);
}
 command needs to implemented by components
providing the interface
 event needs to be handled by components using the
interface
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The Surge Example
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Sensor Reading
 A sensor that reads from the internal voltage sensor,
and displays them on LEDs.
 /opt/tinyos-2.x/apps/Sense
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SenseC Configuration
configuration SenseAppC
{
}
implementation
{
Components SenseC, MainC, LedsC,
new TimerMilliC();
components new DemoSensorC() as
Sensor;
SenseC.Boot -> MainC;
SenseC.Leds -> LedsC;
SenseC.Timer -> TimerMilliC;
SenseC.Read -> Sensor;
}
The application starts after mote is booted
The application connects to the LEDs
Get sensor readings periodically,
controlled by a timer
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Sense Module
module SenseC
{
uses {
interface
interface
interface
interface
}}
Boot;
Leds;
Timer<TMilli>;
Read<uint16_t>;
event void Boot.booted() {
call
Timer.startPeriodic(SAMPLING_FREQUENCY);
}
event void Timer.fired()
{
call Read.read();
}
event void Read.readDone(error_t result,
uint16_t data)
{ // call Leds.led0/1/2 on/off()
}
Start the timer, when time is up,
read the data from sensor
Toggle the LEDs according to the
sensor readings
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Sense Module
event void Read.readDone(error_t result,
uint16_t data)
Integer in numbers of mV
{
if (result == SUCCESS){
Blue LED on if the 3rd lowest bit of data is 1
if (data & 0x0004)
call Leds.led2On();
else
call Leds.led2Off();
if (data & 0x0002)
Green LED on if the 2rd lowest bit of data is
call Leds.led1On();
else
call Leds.led1Off();
Red LED on if the lowest bit of data is 1
if (data & 0x0001)
call Leds.led0On();
else
call Leds.led0Off();
}
}
}
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Note the method of checking bits here!
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Implementation of DemoSensorC
generic configuration DemoSensorC() {
provides interface Read<uint16_t>;
}
Implementation {
components new VoltageC() as DemoSensor;
Read = DemoSensor;
}
tos/platforms/telosb/DemoSensorC.nc
generic configuration VoltageC() {
provides interface Read<uint16_t>;
}
implementation {
components new Msp430InternalVoltageC();
Read = Msp430InternalVoltageC.Read;
}
tos/platforms/telosb/VoltageC.nc
tos/chips/msp430/sensors/Msp430InternalVoltageC.nc
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Reading from more sensors
 Internal temperature sensor of MSP430 chip
 tos/chips/msp430/sensors/Msp430InternalTemperatur
eC.nc
 External temperature, humidity and light sensors
 Temperature: Sensirion SHT11
• tos/platforms/telosa/chips/sht11/SensirionSht11C.nc
 Humidity: Sensirion SHT11
• tos/platforms/telosa/chips/sht11/SensirionSht11C.nc
 Light: Hamamatsu S1087
• tos/platforms/telosa/chips/s1087/HamamatsuS1087ParC.nc
 Efficient display???
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Lab 2 Announcement
 Lab 2 is due 10/7 (5:30pm Wednesday)
 Check out your second sensor from the TA
 5% in final grade
 You will work on it on your own
 Need to let the TA check you off
• Turn in printed program codes after check-off
 Sensor reading and message sending/receiving
 Need to program two motes
• Everyone should check out two more motes from the TA
 Mote1 periodically reads light sensor, displays the readings
on the LEDs, and sends it to the radio
 Mote2 receives the reading and displays it on the LEDs
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