CHIP EFR32 Pigweed Example Application

The EFR32 example demonstrates the usage of Pigweed module functionalities in an application.

The example is based on CHIP, the Pigweed module, which is a collection of libraries that provide different functionalities for embedded systems, and the EFR32 platform.

You can use this example as a training ground for making experiments, testing Pigweed module features and checking what actions are necessary to fully integrate Pigweed in a CHIP project.

Pigweed functionalities are being gradually integrated into CHIP. Currently, the following features are available:

Echo RPC - Creates a Remote Procedure Call server and allows sending commands through the serial port to the device, which makes echo and sends the received commands back.

CHIP EFR32 Pigweed Example Application
- Building the Example Application
  - Flashing the Application
- Testing the Example Application

Building the Example Application

Download or clone the sdk_support from GitHub

    git clone https://github.com/SiliconLabs/sdk_support.git

and export the path with :

    export EFR32_SDK_ROOT=<Path to cloned git repo>

Download the Simplicity Commander command line tool, and ensure that commander is your shell search path. (For Mac OS X, commander is located inside Commander.app/Contents/MacOS/.)
```
    export PATH=/Applications/Commander.app/Contents/MacOS:$PATH
```
Download and install a suitable ARM gcc tool chain: GNU Arm Embedded Toolchain 9-2019-q4-major
Install some additional tools(likely already present for CHIP developers):
- Linux
```
  sudo apt-get install git libwebkitgtk-1.0-0 ninja-build
```
- Mac OS X
```
  brew install ninja
```
Supported hardware:
MG12 boards:
- BRD4161A / SLWSTK6000B / Wireless Starter Kit / 2.4GHz@19dBm
- BRD4162A / SLWSTK6000B / Wireless Starter Kit / 2.4GHz@10dBm
- BRD4163A / SLWSTK6000B / Dual band Wireless Starter Kit / 2.4GHz@19dBm, 868MHz@19dBm
- BRD4164A / SLWSTK6000B / Dual band Wireless Starter Kit / 2.4GHz@19dBm, 915MHz@19dBm
- BRD4166A / SLTB004A / Thunderboard Sense 2 / 2.4GHz@10dBm
- BRD4170A / SLWSTK6000B / Multiband Wireless Starter Kit / 2.4GHz@19dBm, 915MHz@19dBm
- BRD4304A / SLWSTK6000B / MGM12P Module / 2.4GHz@19dBm
MG21 boards: Currently not supported due to RAM limitation.
- BRD4180A / SLWSTK6006A / Wireless Starter Kit / 2.4GHz@20dBm
MG24 boards :
- BRD2601B / SLWSTK6000B / Wireless Starter Kit / 2.4GHz@10dBm
- BRD2703A / SLWSTK6000B / Wireless Starter Kit / 2.4GHz@10dBm
- BRD4186A / SLWSTK6006A / Wireless Starter Kit / 2.4GHz@10dBm
- BRD4186C / SLWSTK6006A / Wireless Starter Kit / 2.4GHz@10dBm
- BRD4187A / SLWSTK6006A / Wireless Starter Kit / 2.4GHz@20dBm
- BRD4187C / SLWSTK6006A / Wireless Starter Kit / 2.4GHz@20dBm

Build the example application:

cd ~/connectedhomeip/examples/pigweed-app/efr32
git submodule update --init
source third_party/connectedhomeip/scripts/activate.sh
export EFR32_BOARD=BRD4161A
gn gen out/debug
ninja -C out/debug

To delete generated executable, libraries and object files use:

  cd ~/connectedhomeip/examples/pigweed-app/efr32
  rm -rf out/

Flashing the Application

On the command line:

cd ~/connectedhomeip/examples/pigweed-app/efr32
python3 out/debug/chip-efr32-pigweed-example.flash.py

With the Commander app, just load the .s37 file.
Or with the Ozone debugger, just load the .out file.

Testing the Example Application

Determine the serial port name for the EFR device by checking /dev: ls /dev/tty*

It should look like this :
- On Linux
    /dev/ttyACM0
- On MAC
    /dev/tty.usbmodem0004401548451

Run the following command to start an interactive Python shell, where the Echo RPC commands can be invoked:

python -m pw_hdlc.rpc_console --device /dev/tty.usbmodem0004401548451 -b 115200 <CHIP_ROOT>/third_party/pigweed/repo/pw_rpc/pw_rpc_protos/echo.proto -o /tmp/pw_rpc.out

To send an Echo RPC message, type the following command, where the actual message is the text in quotation marks after the msg= phrase:
```
rpcs.pw.rpc.EchoService.Echo(msg="hi")
```
Note: Some users might have to install the VCP driver before the device shows up on /dev/tty.

Memory settings

While most of the RAM usage in CHIP is static, allowing easier debugging and optimization with symbols analysis, we still need some HEAP for the crypto and OpenThread. Size of the HEAP can be modified by changing the value of the SL_STACK_SIZE define inside of the BUILD.gn file of this example. Please take note that a HEAP size smaller than 5k can and will cause a Mbedtls failure during the BLE rendez-vous.