Interfacing with Home Assistant

Home Assistant is an open source home automation platform. It has a vast amount of interfaces (over 740 when this article was written). 

They have a well documented Getting Started Guide for Raspberry Pi so we will not cover installing Home Assistant on your Raspberry Pi in this tutorial. Here is the link for common Home Assistant tasks on Raspberry Pi.

What you will need:

1. Any model Raspberry Pi with preferably the full Raspbian distro 
2. Wireless Base Station for Raspberry Pi or Flex RF Module
3. Any wireless sensor

What you need to know beforehand:

1. How to operate a Raspberry Pi
2. You have already set up your wireless base station and tested your sensor
3. Some Python programming knowledge is preferable but not mandatory as we provide you with the source code

Step 1: Download the JemRF MQTT library:

git clone https://github.com/JemRF/MQTT

cd MQTT

Step 2: Install MQTT (if you haven't already)

sudo pip install paho-mqtt

Step 3: Configure your IP address

sudo nano rf2mqtt.py

Page down and edit the ip_address in the Configurations section.

#Configurations===============
DEBUG = True
Fahrenheit = False
mqtt_server = "192.168.2.201" #Enter the IP address of your MQTT server 
topic = "myhome"
device_prefix = "RF_Device"
#=============================

Pres CTRL-X to exit and save.

Step 4: Edit the Home Assistant YAML file and configure MQTT and your sensors

Type: 

sudo nano /home/homeassistant/.homeassistant/configuration.yaml

Then add the following section to the bottom of the file:

mqtt:
broker: 192.168.2.201

# Example configuration.yaml entry temperature & humidity sensor with a DeviceID of 04:

sensor:
  - platform: mqtt
    name: "Temperature"
    state_topic: "myhome/RF_Device04"
    unit_of_measurement: '°C'
    value_template: "{{ value_json.TMP }}"

  - platform: mqtt
    name: "Humidity"
    state_topic: "myhome/RF_Device04"
    unit_of_measurement: '%'
    value_template: "{{ value_json.HUM }}"

Remember to restart the Home Assistant service:

sudo systemctl restart home-assistant@homeassistant.service

Step 5: Run the interface

python rf2mqtt.py

You should see output like this:

pi@raspberrypi:~/MQTT $ python rf2mqtt.py
Sat Aug 4 18:50:12 2018 a04STARTED--
Sat Aug 4 18:50:12 2018 a04STARTED--
Sat Aug 4 18:50:18 2018 a04TMPB25.39
Sat Aug 4 18:50:18 2018 a04TMPB25.39
Sat Aug 4 18:50:18 2018 a04TMPB25.39
Sat Aug 4 18:50:18 2018 a04HUM58.70-
Processing data : DevId=04,Type=4,Value1=25.39,Value2=58.70
{"TMP": "25.39", "HUM": "58.70"}
Sat Aug 4 18:50:18 2018 a04HUM58.70-
Sat Aug 4 18:50:18 2018 a04HUM58.70-
Sat Aug 4 18:50:18 2018 a04SLEEPING-