gan

gan includes some very simple scripts that read data from temperature sensors and save this data locally in CSV files. It is intended to be run on simple Raspberry Pi OS-based machines (usually Raspberry Pi Zero) with attached sensors.

stasi will be used to centralize data from multiple gan sensors and generate graphs.

Supported sensors

• USB-attached DS18B20 sensors. These are nice because they don't require you messing with wires and (some) are waterproof. You can find them on eBay. The downside is they only measure temperature.
• BME280 Breakout can measure temperature, humidity and pressure. You can buy it directly from Pimoroni.

Usage

• Use gan-gen to generate a minimal OS image which includes gan.
• Flash the image to a Micro SD card:
  • On Linux you can use Raspberry Pi Imager (rpi-imager).
  • On Mac you can use balenaEtcher.
• Boot your Pi Zero (with attached sensors - hot-plugging USB devices might not always work!).
• SSH into the Pi.
• If using the DS18B20 USB sensor, you will be using digitemp to read the data. digitemp is already installed on the SD card from gan-gen, but it needs a config file.
  • Generate a config file for digitemp. For example, if you have a single USB sensor, you can run digitemp_DS9097 -i -s /dev/ttyUSB0 && mv ~/.digitemprc ~/.digitemprc-0
• Create a directory to store the data files: mkdir -p /home/gan/data/<SENSOR_NAME>.
• Set up a cronjob that reads the sensors. The data will be saved locally.
  • For example: * * * * * cd /home/gan/data/<SENSOR_NAME> && python3 /home/gan/gan/read_digitemp.py 0
• You will need stasi to collect data from multiple gan sensors and generate graphs.
  • mkdir ~/.ssh && chmod 700 ~/.ssh then add the public key of the machine running stasi to ~/.ssh/authorized_keys

TODO

I use this system for my own home monitoring setup and it works fine, but it might not work for everyone nor is it easy enough to install for everyone.