Build with Ardunio IDE and Board Extension ESP8266WiFi //

Using the following pins:

Function Pin  
Force WLAN Config D4 / GPIO2

Press during normal work, causes acess point to open for WLAN config

declared in local_conf.h

Transmitter D1 / GPIO5 declared in local_conf.h
USB/flashing D9 / GPIO3 fixed
  D10/ GPIO1 fixed
Free (check reset) D8 / GPIO15 must be low for reset (bad with I2C pullups)
  D4 / GPIO2 sometimes used for buildin LED (must be high for reset)
  D3 / GPIO0 must be low for reset

Libraries required:    

Adafruit_MQTT.h Required Adafruit MQTT Lib Version >=0.16.1


Sorcecode is available at

For the hardware use any ESP8266.
For beginners use a module with "buildin" USB (Like NodeMCU or WEMOS D1 mini or D1 minipro).

The receiver MUST be operated with 3.3V (therefor the most "Arduino transmitters" don't work) and you MUST attach an antenna (at least a cable with exactly 17,3cm).
If you coil up the antena you reduce range (or use one of the listed below).

For Gemany:
ACHTUNG! Stellen Sie vor Inbetriebnahme sicher, diese nur mit der zulässigen Sendeleistung zu betreiben. Die aktuellen Bestimmungen können unter überprüft werden.;jsessionid=26A12072F86B6B3DECFD82321C669DA9?__blob=publicationFile&v=5
(Sollte bei einem reinen Empfänger natürlich automatisch der Fall sein.)

For other countries:
Check your allowed frequency (mostly 433MHz or 315MHz), max transmitting power (for example in Germany 10 mW) and what other laws you have to follow.
(Should be no option for a receiver, but better check your lcoal laws.)

Easiest way: Use only official and licensed modules for your country , no self build stuff.

Hardware examples (only examples, I used other parts, but don't have the links anymore):

433MHz transmitter



I use this with my MQTT-broker (
The broker subcribes to the path the receiver is sending the codes received, then it's mapped with codes/devices known via an mysql-table, and sends out a text based answer (ON/OFF) to different MQTT-path (for my OpenHAB).
"Unknown" devices are ignored (or will be mapped/learned in the future for easy learning new devices or to see which house codes are already in use in your neighborhood).