mbed Hands-On
Instructor Workshop
ESWEEK 2013
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Agenda
• mbed Hands-On Instructor Workshop
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The ARM University Program - Khaled Benkrid, ARM UP Manager
Introduction to mbed – Professor James Hamblen Georgia Tech
Hands-on Lab 1: mbed registration and Hello World demo
Hands-on Lab 2: Bubble Level on mbed application board
Hands-on Lab 3: Interfacing with a temperature sensor & PC I/O
Hands-on Lab 4: RTOS and Threads
Instructor Demo Lab 5: Internet Clock
Instructor Demo Lab 6 : HTML5 Web sockets
Instructor Demo Lab 7 : Debugging and Breakpoints in offline compiler
Q&A with Khaled Benkrid and Joe Bungo ARM University Program
Introduction to mbed
James Hamblen
Georgia Tech ECE
Atlanta, GA USA
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What’s happening in Microcontrollers?
• Microcontrollers are getting cheap
– 32-bit ARM Cortex-M3 Microcontrollers @ $1
– 32-bit ARM Cortex-M0+ Microcontrollers @ $0.50
• Microcontrollers are getting powerful
– Lots of processing, memory, I/O in one package
• Microcontrollers are getting interactive
– Internet connectivity, new sensors and actuators
• Creates new opportunities for microcontrollers
Rapid Prototyping
• Rapid Prototyping helps industries create new products
– Control, communication and interaction increasingly define products
– Development cycles for microelectronics have not kept pace
3D Moulding
3D Printing
2D/3D Design
Web Frameworks
mbed.org - Rapid Prototyping for
MCUs
• Fastest way to get started with ARM microcontrollers
– Plug ‘n’ Play Hardware, Online Compiler
– Get setup and run “Hello World!” in 60 seconds
– Removes entry barriers to MCU technology
• Focused on rapid prototyping for a diverse audience
– DIP form-factor, High-level APIs, Developer website
– Technology and trade-offs to enable fast experiments
– Creates new applications for MCU technology
• Launched at ESC Boston with live demo
– Internet-enabled “Twittering Billy” read out tweets
– An embedded internet device, prototyped in ½ day
– Over ¼ million video views in first week!
mbed Rapid Prototyping Platform
• Complete Hardware, Software and Web 2.0 Solution
Dedicated Developer Website
Lightweight Online Compiler
High-level Peripheral APIs
Prototyping Form-Factor
mbed Website
• Dedicated Developer Web Platform
– Custom Web 2.0 tools and environment focused on developers
– Simple route to get started, comprehensive resources and support
http://mbed.org
mbed Compiler
• Lightweight Online C/C++ Compiler
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Web 2.0 browser-based IDE with personal workspace “in the cloud”
Nothing to install or configure, login from anywhere
Industry leading RVCT 4.1 back end. It is a real tool!
Very easy to use, great for students!
mbed SDK
• C/C++ SDK for ARM Microcontrollers
– High-level APIs and standard environment
– Low level control as needed
– Portable across different ARM silicon vendor MCUs
• Built on industry standard technology
– ANSI/ISO C/C++
– CMSIS Compliant
– Compatible with all major professional MCU tools
• Open Source
– Released under permissive Apache 2.0 license
– Suitable for commercial and non-commercial use
– Managed, maintained and tested by ARM
mbed API Library
• High-level Peripheral APIs using C++ Classes
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Trading a bit of memory and CPU performance for ease of use
Abstract software interfaces for controlling microcontroller hardware
Intuitive peripheral access, encapsulation of implementation details
Treat hardware and software the same
mbed-enabled Hardware
• Expanding range of off-the-shelf mbed-enabled hardware
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ARM Cortex-M0, M0+, M3 all represented; M4 TBA
All boards implement the mbed HDK
Hardware is designed and/or made by ARM or 3rd parties
mbed HDK enables anyone to build alternate board designs
mbed LPC1768 Microcontroller
• Cortex-M3 MCU in a Prototyping Form-Factor
– 0.1” pitch DIP with “USB Flash Drive” interface and support
components
– Nothing to install or configure, practical for breadboard and PCBs
What IO is there?
Courses that could utilize
an embedded computer
• C/C++ Programing Class – Need easy to use full C++ support
• Computer Architecture – Need C and ARM? Assembly Language
• Microprocessor/Embedded Systems Design - Need C/C++, most
common I/O interfaces, Networking and OS support.
• Senior Design Projects– Needs to be easy to add custom hardware
and build prototypes. Networking and RTOS needed in many
cases.
• Elective Courses
– Robotics/Mechatronics: Need extensive easy-to-use I/O support
– Networking: Need Ethernet TCP/IP support for “Internet of Things” Devices
– Operating Systems: Need RTOS (Open Source)
Using mbed at Georgia Tech
• For the past two years, all undergraduate ECE students
purchase their own mbed computer board and a parts kit that
is used in several undergraduate classes for hands-on
laboratory assignments. Total cost is just under $100.
• Supports full C/C++, ARM Assembly Language, Networking,
and an optional Operating System along with a wide range of
I/O interfaces.
• The cloud compiler and a C++ I/O API library make it easy to
use
• Student breadboards can be used to build custom embedded
systems and this also enables use later in design projects.
Students can work anywhere with mbed
• A PC or Mac with a Wi Fi or wired network connection and a web browser
is all that is needed with the cloud compiler
• Downloads new C/C++ code files just like a USB flash drive
• Breadboard is powered by the USB connection (5V and 3.3V)
• A Wi Fi to Ethernet bridge setup can even be used on a laptop for
developing and testing “Internet of Things” applications
• Wiki eliminates requirement for a dedicated textbook on the device
ECE students working in hallway
A traditional student laboratory setup
Rapid Prototyping using a Breadboard
GT student mbed Inventor’s Kit
Internet of Things Example:
NTP Clock on a Breadboard
Experience using mbed at Georgia Tech
• The cloud compiler and breadboard approach works well and greatly
reduces the student computer and lab support issues. Breadboarding
provides increased flexibility for laboratory and design projects.
• Higher-level I/O support with C/C++ APIs and wiki documentation enables
the introduction of embedded systems earlier in the curriculum.
• Assembly Language, RTOS, and networking support enables future use in
additional undergraduate courses and senior design projects.
• The majority of students wanted more embedded assignments and felt
that the breadboarding experience was worthwhile.
ECE Students working on mbed project
HKN mbed inventor’s kit sales
Breadboard or Baseboard?
• A breadboard allows students to generate a custom hardware
design adding new parts as needed. There is some
educational value in having students connect parts. Most I/O
connections are serial, so few wires are needed.
• The mbed module can also plug into a baseboard with an
assortment of parts already hooked up. To use parts on
baseboard a breadboard and jumper wires are not needed.
Can still run long jumper wires to a breadboard. Less time to
get started, but perhaps harder to use in design projects with
custom hardware needs.
• The mbed application board is a new low-cost baseboard
option for mbed that will be used in the hands-on demos
mbed application board
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128x32 Graphics LCD
5 way joystick
2 x Potentiometers
3.5mm Audio jack (Analog Out)
Speaker, PWM Connected
3 Axis +/1 1.5g Accelerometer
3.5mm Audio jack (Analog In)
2 x Servo motor headers
RGB LED, PWM connected
USB-B Connector
Temperature sensor
Socket for for Xbee (Zigbee) or RN-XV (Wifi)
USB-A Connector
RJ45 Ethernet connector
1.3mm DC Jack input
http://mbed.org/cookbook/mbed-application-board
Connecting up the TextLCD
• The LCD module has an SPI interface and a few digital outputs
for reset, chips select and so on
• mbed keeps it simple
– Libraries in Cookbook Wiki for many common I/O devices
– Standard C/C++ interface via printf
– Hello World : http://mbed.org/users/chris/code/app-board-LCD
Hands-On Labs
• First Connect to Wi-Fi – needed for cloud compiler!
– Connect to “Marriot_CONF” using auth code: 98HKM
– If above not working, try “Marriot_GUEST” using room number and
last name
• Open the page below in a web browser:
https://mbed.org/users/4180_1/notebook/mbed-applicationboard-hands-on-demos/
Note: Keep this web page open while using the compiler in
another browser tab for links to import demo projects and follow
along instructions throughout the demos
ARM University Program mbed workshop videos
• http://www.youtube.com/playlist?list=PLgyFKd2HIZlaJM1b0Y
q0tvWnddQ7D6Dae
• Application boards and mbeds are available at:
www.sparkfun.com/products/11695
• Other sources at:
• mbed.org/cookbook/mbed-application-board#where-to-buy
Summary
• There is huge opportunity for microcontroller applications
– A major barrier to adoption is simple experimentation
• mbed helps with getting started and rapid prototyping
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Fast turnaround of experiments and prototyping new ideas
Try out new technology and new ideas
Easy for students to use
Handbook and Cookbook Wiki provide documentation and examples
• Makes the technology very accessible for students
– Hands-on demos will show a start to finish prototyping example
– From getting a user started to enabling an application experiment
Q&A