rtl433_to_mqtt

Simple ruby script to be used with a Software Defined Radio (SDR) with the rtl-sdr libraries and the rtl_433 tool that scans 433.9 MHz and decodes traffic from things like temperature sensors.

This tool is focused on:

• Run the rtl_433 command and parses the JSON formatted messages.
• Captures messages into a log file with automatic daily log-rotation.
• De-duplicates messages.
  • Some sensors send triplicate messages to ensure delivery. Script drops dups.
• Adds a current unix timestamp ts value to the payload.
• Publish de-duplicated messages onto an MQTT topic.

This allows downstream MQTT clients to subscribe to the de-duplicated feed for filtering, logging, and analysis.

Included tools:

• setup.sh - debian/ubuntu/raspbian setup script to install needed dependancies to use this.
• rtl433_to_mqtt.rb - core tool that does the work
• launch.sh - simple launcher for the rtl433_to_mqtt.rb that will automatically, after 5 seconds, relaunches the tool incase it dies.
• tmux-launch.sh - create a new tmux session and runs launch.sh

software setup

Install on a Raspberry Pi with Raspbian is super simple!

git clone https://github.com/dayne/rtl433_to_mqtt
cd rtl433_to_mqtt
sudo ./setup.sh
# wait a while and say yes to a few things
sudo reboot

Login and you should be ready to configure and launch the collection script

cd rtl433_to_mqtt # location of code
./launch.sh

Default configuration in the config.yml.example will have all the messages pushed to default MQTT server and topic.

• server: localhost
• topic: /rtl_433/raw

You can watch that default flow by opening up a terminal and using mosquitto_sub to watch that local topic:

mosquitto_sub -h localhost -t /rtl_433/raw

To customize the MQTT broker or topic published copy the config.yml.example to config.yml and change appropriately.

The details of setup.sh:

Install rtl-sdr libraries and drivers: more details

apt install rtl-sdr
echo "blacklist dvb_usb_rtl28xxu" | sudo tee -a /etc/modprobe.d/blacklist-rtl.conf
reboot

Install rtl_433 via the build instructions

Install mosqitto MQTT server and ensure it is launched

sudo apt install mosquitto

Runs ruby bundler to get the script dependancies.

usage

cp config.yml.example config.yml
# edit to point at your mqtt server (or leave alone for localhost)
./launch.sh

If you want to launch in tmux: use ./tmux-launch.sh

Autolaunch on reboot? Add the following line to your crontab: (fix the path of course)

@reboot /home/pi/projects/rtl433_to_mqtt/tmux-launch.sh

hardware requirements

• Raspbery Pi $50
• A USB Software Defined Radio (SDR) like the NooElec NESDR Mini USB RTL-SDR $20
• External/Internal temp sensor that broadcasts on 433 Mhz like the AcuRite-06002M $12