# Matter Arm Mbed OS Lighting Example Application
The Arm Mbed OS Lighting Example demonstrates how to remotely control a dimmable
white light source. The example takes advantage of the IO available on board:
- A button press turns the light on or off.
- Intensity can be displayed and changed depending on the target IO (PWM
output, slider).
You can use this example as a reference for creating your own application.
The example is based on
[Matter](https://github.com/project-chip/connectedhomeip) and Arm Mbed OS, and
supports remote access and control of lighting over a WiFi network.
The example behaves as a Matter accessory, in other words a device that can be
paired into an existing Matter network and can be controlled by this network.
Pigweed functionalities are also integrated into this application. The Remote
Procedure Call (RPC) server is created. It allows sending commands through the
serial port to the device. The following RPC protocols services are available:
- **Device** - perform basic operations on device: reboot, factory reset,
software update or get basic device information
- **Button** - trigger specific button event (push/release)
- **Lighting** - set/get lighting state (on/off/brightness level)
- [Overview](#overview)
- [Bluetooth Low Energy advertising](#bluetooth-low-energy-advertising)
- [Bluetooth Low Energy rendezvous](#bluetooth-low-energy-rendezvous)
- [WiFi provisioning](#wifi-provisioning)
- [Run application](#run-application)
- [Environment setup](#environment-setup)
- [Building](#building)
- [Flashing](#flashing)
- [Debugging](#debugging)
- [Testing](#testing)
- [Serial port terminal](#serial-port-terminal)
- [CHIP Tools](#chip-tools)
- [RPC console](#rpc-console)
- [Supported devices](#supported-devices)
- [Notes](#notes)
- [Device UI](#device-ui)
- [Notes](#notes-1)
## Overview
The Matter device that runs the lighting application is controlled by the Matter
controller device over WiFi. By default, the Matter device is disconnected , and
it should be paired with Matter controller and get configuration from it.
Actions required before establishing full communication are described below.
### Bluetooth Low Energy advertising
To commission the device onto a Matter network, the device must be discoverable
over BLE. The BLE advertising starts automatically after device boot-up.
### Bluetooth Low Energy rendezvous
In Matter, the commissioning procedure (called rendezvous) is done over BLE
between a Matter device and the Matter controller, where the controller has the
commissioner role.
To start the rendezvous, the controller must get the commissioning information
from the Matter device. The data payload is encoded within a QR code, printed to
the UART console.
### WiFi provisioning
The last part of the rendezvous procedure, provisioning involves sending the
network credentials from the Matter controller to the Matter device. As a
result, device is able to join the network and communicate with other devices in
the network.
## Run application
### Environment setup
Before building the example, check out the Matter repository and sync submodules
using the following command:
```
$ git submodule update --init
```
Building the example application requires the use of **ARM Mbed-OS** sources and
the **arm-none-gnu-eabi** toolchain.
The Cypress OpenOCD package is required for flashing purpose. Install the
Cypress OpenOCD and set env var `OPENOCD_PATH` before calling the flashing
script.
```
cd ~
wget https://github.com/Infineon/openocd/releases/download/release-v4.3.0/openocd-4.3.0.1746-linux.tar.gz
tar xzvf openocd-4.3.0.1746-linux.tar.gz
export OPENOCD_PATH=$HOME/openocd
```
Some additional packages may be needed, depending on selected build target and
its requirements.
> **The VSCode devcontainer has these components pre-installed. Using the VSCode
> devcontainer is the recommended way to interact with Arm Mbed-OS port of the
> Matter Project.**
>
> **Please read this [README.md](../../..//docs/VSCODE_DEVELOPMENT.md) for more
> information about using VSCode in container.**
To initialize the development environment, download all registered sub-modules
and activate the environment:
```
$ source ./scripts/bootstrap.sh
$ source ./scripts/activate.sh
```
If packages are already installed then you just need to activate the development
environment:
```
$ source ./scripts/activate.sh
```
### Building
The Lighting application can be built in the same way as any other Matter
example ported to the mbed-os platform.
- **by using generic vscode task**:
```
Command Palette (F1) => Run Task... => Run Mbed Application => build => lighting-app => (board name) => (build profile) => (build type)
```
- **by calling explicitly building script:**
```
${MATTER_ROOT}/scripts/examples/mbed_example.sh -c=build -a=lighting-app -b= -p= -T=
```
Both approaches are limited to supported evaluation boards which are listed in
[Supported devices](#supported-devices) paragraph.
Mbed OS defines three building profiles: _develop, debug_ and _release_. For
more details please visit
[ARM Mbed OS build profiles](https://os.mbed.com/docs/mbed-os/latest/program-setup/build-profiles-and-rules.html).
There are also three types of built application: _simple, boot_ and _upgrade_:
- **simple** - standalone application, mainly for developing and testing
purpose (all building profiles are supported)
- **boot** - signed application + bootloader, it supports booting process and
can be use for firmware update (only _release_ building profiles is
supported)
- **update** - signed application, application image can be used for firmware
update (only _release_ building profiles is supported)
When using the building script, it is possible expand the list of acceptable
targets; this may be useful for rapid testing of a new mbed-targets.
### Flashing
The Lighting application can be flashed in the same way as any other Matter
example ported to mbed-os platform.
The [Open On-Chip Debugger](http://openocd.org/) is used to upload a binary
image and reset the device.
- **by using VSCode task**:
```
Command Palette (F1) => Run Task... -> Run Mbed Application => flash => lighting-app => (board name) => (build profile)
```
- **by calling explicitly building script:**
```
${MATTER_ROOT}/scripts/examples/mbed_example.sh -c=flash -a=lighting-app -b= -p=
```
- **by using VSCode launch task**:
```
Run and Debug (Ctrl+Shift+D) => Flash Mbed examples => Start Debugging (F5) => (board name) => lighting-app => (build profile)
```
The last option uses the Open On-Chip Debugger to open and manage the gdb-server
session. Then gdb-client (arm-none-eabi-gdb) upload binary image and reset
device.
It is possible to connect to an external gdb-server session by using specific
**'Flash Mbed examples [remote]'** task.
### Debugging
Debugging can be performed in the same was as with any other Matter example
ported to mbed-os platform.
The [Open On-Chip Debugger](http://openocd.org/) is used to to open and manage
the gdb-server session. Then gdb-client (arm-none-eabi-gdb) connect the server
to upload binary image and control debugging.
```
Run and Debug (Ctrl+Shift+D) => Debug Mbed examples => Start Debugging (F5) => (board name) => lighting-app => (build profile)
```
It is possible to connect to an external gdb-server session by using specific
**'Debug Mbed examples [remote]'** task.
### Testing
#### Serial port terminal
The application traces are streaming to serial output. To start communication
open a terminal session and connect to the serial port of the device. You can
use **mbed-tools** for this purpose
([mbed-tools](https://github.com/ARMmbed/mbed-tools)):
```
mbed-tools sterm -p /dev/ttyACM0 -b 115200 -e off
```
After device reset these lines should be visible:
```
[INFO][CHIP]: [-]Mbed lighting-app example application start
...
[INFO][CHIP]: [-]Mbed lighting-app example application run
```
The lighting-app application launched correctly and you can follow traces in the
terminal.
#### CHIP Tools
Read the
[MbedCommissioning](../../../docs/platforms/mbedos/mbedos_commissioning.md) to
see how to use different CHIP tools to commission and control the application
within a WiFi network.
#### RPC console
The RPC console is an interactive Python shell console, where the different RPC
command can be invoked. It is a complete solution for interacting with hardware
devices using pw_rpc over a pw_hdlc transport. For more details about Pigweed
modules visit [Pigweed modules](https://pigweed.dev/module_guides.html).
** Building and installing
**
To build and install the RPC console check the guide
[CHIP RPC console](../../common/pigweed/rpc_console/README.md).
** Run
**
To start the RPC console run the following command and provide device connection
parameters as arguments:
- --device/-d the serial port to use.
- --baudrate/-b the baud rate to use.
- --output/-o the file to which to write device output (HDLC channel 1),
provide - or omit for stdout.
- --socket-addr/-s alternatively use socket to connect to server, type default
for localhost:33000, or manually input the server address:port.
Example:
```
chip-console -d /dev/ttyUSB0 -b 115200 -o /tmp/pw_rpc.out
```
To control the lighting type the following command, where you define if 'on'
state is true or false:
```
In [1]: rpcs.chip.rpc.Lighting.Set(on=True)
```
The response from the device should be:
```
Out[1]: (Status.OK, pw.protobuf.Empty())
```
To check the lighting state type the following command:
```
In [1]: rpcs.chip.rpc.Lighting.Get()
```
The response from the device should contain the current lighting state:
```
Out[1]: Status.OK, chip.rpc.LightingState(on=True))
```
For more details about RPC console and supported services visit
[CHIP RPC console](../../common/pigweed/rpc_console/README.md).
### Supported devices
The example supports building and running on the following mbed-enabled devices:
| Manufacturer | Hardware platform | Build target | Platform image | Status | Platform components |
| ----------------------------------------------------- | ------------------------------------------------------------------------- | --------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | :----: | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [Cypress
Semiconductor](https://www.cypress.com/) | [CY8CPROTO-062-4343W](https://os.mbed.com/platforms/CY8CPROTO-062-4343W/) | `CY8CPROTO_062_4343W` | CY8CPROTO-062-4343W
LEDs
- Board has only one usable LED (LED4) which corresponds to USER LED from UI.
- Lighting LED should be an external component connected to PB9_6 pin (active high).
Buttons
- SW2 push-button is not used in this example due to its interaction with WIFI module interrupt line.
- Button 0 corresponds to BTN0 capacitive button.
- Button 1 corresponds to BTN1 capacitive button.
Slider
- The board's touch slider corresponds to UI slider