Build a Test Setup for Micro ROS

[mike-matera]

A lot of work is going to have to come together if we're going to use Micro ROS. We need a hardware and software environment to enable development and testing. The first step is to build the hardware.

Hardware Environment

Should look like this:

RPI4 ---<uart>--- Pi Pico ---<i2c>--- IMU 
Laptop ---<usb>---^

RPi4 Software

The RPi4 has to run the Micro ROS agent software to bridge the messages coming over the UART to the network. The agent is available as source code, as a snap (x86-64 only) and as a Docker container. The easieset way to get this working on the Pi is via docker. The tasks here are:

1. Install the docker.io package on the PI
2. Add all users to the docker group
3. Update the launch configuration to launch the bridge node
4. Document how to independently launch the brige node

Pi Pico Micro ROS SDK

Getting software on the Pi Pico is a bit of a developer challenge. For now, let's assume we're only going to compile Pi Pico software on a laptop. People working on it should follow the instructions here:

https://ubuntu.com/blog/getting-started-with-micro-ros-on-raspberry-pi-pico

Here are some tasks:

1. Start by building and flashing the example program
2. Research how to use the Pi Pico to access the IMU over I2C
3. Add code to the example project to publish IMU messages

For now work in the example. We'll create a separate project later.