Install pi_mqtt_gpio on Raspbian

Posted byMvandeK

I want to receive a notification when someone rings the doorbell at my front door. For this I can buy all kinds of expensive (wireless) doorbells, but I want to use the existing wiring. Because I use Home Assistant for all kinds of automation at home, I also want to integrate this into Home Assistant. Since there is already a Raspberry Pi in the meter cupboard for reading my smart meter, this seemed a logical addition to me.

For this I found this repository: https://github.com/flyte/pi-mqtt-gpio

This Python application does exactly what I want:

  1. It reads the GPIO pins from the Raspberry Pi Board
  2. It allows me to configure which pins have to be read
  3. It allows the Pi to send the information to an MQTT broker

This allows me to use my Home Assistant installation to notify me when someone rang my doorbell, thereby always being informed when someone was at my front door, even when I’m not at home. It also makes it possible to automatically turn on a light in the hallway when it’s dark.

It was a little headache to make it work on my Raspberry Pi 3b with Raspbian, so that’s why I wrote down the instructions.

All the commands are executed as root user

Virtual Env

First you need to create a virtual environment with Python version 3, in /home/pi

/home/pi# python3 -m venv pi_mqtt_gpio

Next, you enter the virtual environment

/home/pi# . pi_mqtt_gpio/bin/activate

Your shell should now show this:

(pi_mqtt_gpio) root@rpi3:

Install the following packages with pip3 (if it’s not installed, use apt install python3-pip)

  • pi_mqtt_gpio
  • rpi.gpio
(pi_mqtt_gpio) root@rpi3: pip3 install rpi.gpio pi_mqtt_gpio

In addition, other packages are also installed (enum34, PyYAML, cerberus, paho-mqtt)

Configuration

In the configuration file you define which MQTT broker the data should be sent to, but also to which GPIO pins should be listened.

Read more about the configuration of pi_mqtt_gpio on this Github page.

Note: this tutorial assumes you save the file pi-mqtt-gpio-config.yaml in the folder /home/pi

Supervisor

Supervisor is a client/server system that allows its users to monitor and control a number of processes on UNIX-like operating systems.

Install Supervisor

apt install supervisor

Open the Supervisor configuration folder 

cd /etc/supervisor/conf.d/

Create a new file with the filename pi_mqtt_gpio.conf

nano pi_mqtt_gpio.conf

Add the following lines:

[program:pi_mqtt_gpio]
command = /home/pi/pi_mqtt_gpio/bin/python -m pi_mqtt_gpio.server /home/pi/pi-mqtt-gpio-config.yaml
autorestart = false # added to avoid a restart loop
directory = /home/pi
redirect_stderr = true
stdout_logfile = /var/log/pi-mqtt-gpio.log

Update supervisor to include this program during the startup of the operating system:

supervisorctl update

This should give the following output:

pi_mqtt_gpio: updated process group

Now it’s time to start pi_mqtt_gpio with Supervisor

supervisorctl start pi_mqtt_gpio

This should give the following output:

pi_mqtt_gpio: started

Check the logfile for the correct operation of the program:

tail -f /var/log/pi-mqtt-gpio.log

An example of an working configuration:

2020-04-28 12:06:28,550 mqtt_gpio (INFO): Startup
2020-04-28 12:06:29,039 mqtt_gpio (INFO): Connected to the MQTT broker with protocol v3.1.1.
2020-04-28 12:06:29,049 mqtt_gpio (INFO): Polling: Input 'doorbell' state changed to False

Now you can connect a doorbell to your Raspberry Pi. When you ring the doorbell, a message should be sent to your MQTT broker.