Balena Sense HAT

A balenaCloud project using a Raspberry Pi 4 together with a Sense Hat.

Components

• messenger - The messenger container offers a REST API to display messages on the Sense Hat display, for example:

  uuid=$(balena devices | grep <app-name> | awk '{print $2}')
  ip=$(balena device $uuid | grep "IP ADDRESS" | awk -F ':' '{print $2}' | xargs)
  curl -X POST -H "Content-Type: application/json" -d '{"message": "hello world"}' $ip:5000/display

• sensor - the sensor component reads the sensors of the SenseHat and writes it into a InfluxDB database.

• dashboard - Grafana dashboard displaying the sensor data.

Deployment

balena push <app-name>

Development

Executing code in container

In order to test the code easily, the container uses a trick to allow using PyCharm locally and execute the code in the remote container. For that the container needs to open an SSH port. This can be achieved setting the device service variable START_SSHD=1. This will start sshd and allow PyCharm to use the container as a remote execution environment.