ESP8266 gateway: MQTT to 433mz

Minimalistic MQTT to 433mz remote socket gateway for ESP8266

A robust and minimalistic mqtt to 433mhz gateway for the esp8266. Enables cheap wireless sockets from the DIY store to be controlled via the MQTT home automation server. This project follows a minimalist approach, designed solely for reliability and easy Node-RED integration.

Requirenments

• ESP8266 board definition ( https://arduino-esp8266.readthedocs.io/en/latest/installing.html )
• PubSubClient.h ( https://pubsubclient.knolleary.net/ )
• RCSwitch.h ( https://github.com/sui77/rc-switch )
• ESP8266WiFi.h ( https://github.com/esp8266/Arduino/tree/master/libraries/ESP8266WiFi )
• Ticker.h ( https://github.com/esp8266/Arduino/tree/master/libraries/Ticker )

Install

• Download 433mhz_mqtt_gateway.ino
• Set wifi settings (ssid and passsword)
• Set mqtt settings (mqttServer, mqttPort, mqttUser, mqttPassword)
• Deploy to your esp8266

Node-RED integration

• Install the default mqtt node
• Create a function containing nodered_function.js:

Background information

• 433mhz sender is expected to be on pin 12 of the esp8266 but can be changed by changing "TRANSMIT_PIN"
• main loop has to finish every cycle in 10 seconds or the watchdog restarts the device
• if wifi reconnect fails 5 times in a row, the revice restarts

Further Improvements (maybe... maybe not):

• MQTT over TLS ( + verify certificate fingerprint )
• port project to esp32 and use firmware encryption to protect the passwords
• publish sensor values (dht22?) to mqtt