set up rflink to respond to 433MHz devices and then integrate them with Home Assistant
In this project we integrate inexpensive 433MHz RF devices with modern smart devices
see also: 433MHz smarter letterbox
how to set up RFlink so that it will read your RF sensors
The easiest ready-to-roll device to integrate 433MHz RF devices with smart home kit is the Sonoff RF Bridge. For example, I used it to sense when a door contact sensor reacts. I have 433MHz RF door bell buttons which I use to switch the room lights. In both cases a sensor transmits a wireless RF pulse which is picked up by a Sonoff RF Bridge. The bridge relays an MQTT message to Home Assistant. And then you can do anything.
But those may be lucky examples of compatibility. The Sonoff RF Bridge doesn’t respond to or control a lot of RF devices. You’d need to modify the Bridge (really hard) and install OpenMQTTGateway on the bridge to give it that capability (really hard as I couldn’t find step-by-step instructions). And then you’d still find devices that the bridge didn’t respond to. Luckily I stumbled upon RFlink – an alternative that is capable of recognising Oregon Scientific, HomeEasy and Friedland RF devices – and switching them too. Setting up my Rflink project took ages because the instructions are all over the place. The rest of this page seeks to put them in one place.
what you need
- A Raspberry Pi running Home Assistant
- An Arduino Mega R3 or clone (£10) to plug into the Raspberry Pi with a USB cable. I bought a clone Mega R3 from China. You just need an Arduino Mega R3 – anything else requires effort to save a £
- An RF transmitter and RF receiver and some wires (as below = under £5). Or you can buy a kit from Nodo webshop
- A tiny bit of soldering skill to attach the aerials
- Some 433MHz devices eg doorbell, alarm, PIR sensors that you want to make use of
- The RFlink firmware / software for the Arduino on a Windows PC.
install RFlink on the Arduino (in Windows)
Plug the Arduino Mega R3 into a Windows PC with a USB cable. Windows should install the necessary drivers for the CH340 and assign a COM port so that we can upload the software.
Above: download the RFlink firmware/software for the Arduino. Open the zip and launch the RFlinkloader application. Below: when the application launches it should find the COM port.
Notice that the software has a button to scan the available ports, a drop-down to select a COM port and a button to select the firmware file (rflinkloader.cpp.hex). You might need to press one of the physical buttons on the Arduino to wake it up. The firmware file uploads and your Arduino should be ready to go. When you click Serial port Logging you’ll see some signs that the software is working. Disconnect the Arduino to add the RF receiver kit next.
add the receiver and transmitter to the Arduino
You need six male-to-female Dupont wires, three for the RF transmitter and three for the RF receiver. Solder the correct aerial to the Antenna hole in each board. Connect them to the Arduino Mega as follows because the firmware is expecting to see things on the pins used here.
reconnect the Arduino to the Windows PC running RFlinkloader
With the Arduino and the RF kit connected to the PC click Serial port logging. Now send a signal from one of your RF devices and you ought see some output on the screen. Make a note of the device and what it’s recognised as. I’d recommend that you now power down everything to achieve radio silence and then steadily identify the name and code of as much kit as you have. You can copy and paste the log text or write this on paper. I wish I’d done this thoroughly.
If you find that some devices aren’t recognised, click Debug in the Rflinkloader window. You’ll at least find that they are working. I had the least success with piezo RF doorbells and I guessed that the reason is to do with them being coded or tied to the receivers. You might contact the RFlink software maker but first read how the protocol works here.
connect the Arduino to the Raspberry Pi running Home Assistant to get the USB port name
Click Supervisor > System > Hardware. If needed reboot the RPi to get the USB serial port. See the official docs
add some code to your configuration.yaml
The following code adds the RFlink integration and sets it to auto remember any RF signals it receives. Devices that are sensors (eg Oregon Scientific weather station) will be set as sensor entities. All other devices are understood as lights. Later on we’ll fix this and more. Right now, check your configuration and then reboot the Raspberry Pi.
rflink: port: /dev/serial/by-id/usb-1a86_USB2.0-Serial-if00-port0 logger: default: error # add the following to the existing logger section logs: rflink: debug homeassistant.components.rflink: debug light: # add the following to the existing light section - platform: rflink automatic_add: true sensor: # add the following to the existing sensor section - platform: rflink automatic_add: true
add the entities to your Home Assistant overview and automations
From now on Rflink will store the devices it discovers to Home Assistant. Home Assistant will create an entity for anything new. Of course you can display the state of the entities in the Overview / front page. However you must now do the work of identifying what sensor is what.
check the logs for probs
When the discovery above takes place Home Assistant keeps a log in the background. You can access this in the config folder – it might help you identify which device is which.
configure the light entities, write automations and scripts
When your switches (push switch; remote button) have all been identified (as lights) you can comment out the automatic_add line in your configuration.yaml. You next step will be to configure the lights as switches. Notice the name “newkaku_004c899e_b” (below) which tells you the protocol, the code and the unit number needed to send the switch signal from Home Assistant to your device. I found that my things worked better when I added the switch detail – though it might not be essential.
switch: platform: rflink devices: newkaku_004c899e_b: name: heunit1 friendly name
You can now place the entities you found on the Overview of Home Assistant. You can also incorporate the entities into an automation that turns on a light when a button is pressed.
keep a record of your codes!
I now put a label on each item and keep a record of the device RF codes and so on in a handy Google spreadsheet.