Beer Temperature Monitor

A Python service that relays a Raspberry Pi temperature to an external service for processing.

More info to come later!

Requirements

• Raspberry Pi (current development on Raspberry Pi Zero)
• Adafruit MCP9808 Temperature sensor
• Virtualenv

Prerequisites

Python virtualenv

Running this project becomes infinitely easier when run in a virtual environment.

Install virtualenv (assuming you have access to python3):

$> python3 -m venv venv

Once virtualenv is installed, activate it:

$> source venv/bin/activate

From here, you should be able to follow the Install section.

Install

1. Download repo

2. Go into project folder

   $> cd beer_temp_monitor

3. Install required packages

   $> pip install -r requirements.txt

4. Run the monitor! (Currently, receiving server must be up and running!)

   $> python src/beer_temp_monitor.py

Auto Start

This project is meant to run on the Pi at boot, without intervention. To that end, I currently use systemd to start the program on boot. More info on systemd here.

Details on how to accomplish this can be found here and here.

I thought I'd share some particulars on the systemd service file that eventually worked for me. In the following service file:

[Unit]
Description=Beer Monitor Service
After=multi-user.target

[Service]
Type=forking
User=pi
ExecStart=/bin/bash /home/pi/scripts/beer-monitor.sh > /home/pi/    service-logs/monitor.log 2>&1

[Install]
WantedBy=multi-user.target

Type was set to forking, because I run this project in a detched screen. My previous attempt had it set to simple. It failed, however, because simple tells systemd that the main process is meant to run forever. In contrast, Screen is doing the opposite; it starts a new session and forks to background. Details on how I discovered this can be read in the answer found here.

I wanted to run this script, and ultimately the project, as the user that the pi is setup on, so User is set to pi_user, where pi_user is whatever your user is.