Smart Home 433MHz RF <-> MQTT Gateway with some extras

Smart Home 433Mhz RF <-> MQTT Gateway with some extras

This project was originally published on my personal homepage. The MQTT-433mhz-gateway-homie project is a simple bidirectional gateway to transmit and receive 433Mhz RF signals connected to MQTT. The gateway is built with a cost-effective ESP8266 WiFi chip (I used a Wemos D1 mini, NodeMCU will do as well), simple 433Mhz RF modules and an additional BMP085 sensor.

It enables you to:

• receive MQTT data from a topic and send the 433Mhz signal.
• receive 433Mhz signal from a traditional remote, optional map it to a channel and publish the data to a MQTT topic.
• additionally, a simple temperature sensor can record the room temperature of the room where the gateway is installed.

The software is based on Homie to enable an easy integration with home automation systems like OpenHab.

Hardware

• ESP8266 (Wemos D1 mini, Nodemcu)
• RF Receiver 433Mhz
• RF Transmitter 433MHz
• BMP085 or BMP180 sensor breakout

I got the RF modules from https://www.sparkfun.com, others will do as well. Additionally, I got some Wemos Protoboards, an USB power supply with a very short cable, and an enclosure to hold it all together.

Building the circuit

Software

The following software libraries are used. If using PlatformIO all dependencies are resolved automatically.

• Homie V2 (dev) including dependencies
• RCSwitch
• Adafruit BMP085 Unified
• Adafruit Unified Sensor
• Optionally, PlatformIO environment for building the code

MQTT

For a detailed documentation of the MQTT topics and commands used, see Homie documentation. Sample gateway messages:

homie/mqtt-gateway-livingroom/$homie 2.0.0 
homie/mqtt-gateway-livingroom/$implementation esp8266 
homie/mqtt-gateway-livingroom/$implementation/config {"wifi":{"ssid":"XYZ"},"mqtt":{"host":"192.168.1.20","port":1883,"auth":false},"name":"JaMa Villa MQTT Gateway Livingroom","ota":{"enabled":false},"device_id":"mqtt-gateway-livingroom","settings":{"temperatureOffset":-8.0,"channels":"o-1:[139400];o-2:[139707];o-3:[1398097,1398100];o-4:[139803];i-1:[44618];i-2:[44620];i-3:[44623];i-4:[44638];i-5:[44700];","temperatureInterval":300}} 
homie/mqtt-gateway-livingroom/$implementation/version 2.0.0 
homie/mqtt-gateway-livingroom/temperature/$type temperature 
homie/mqtt-gateway-livingroom/temperature/$properties unit,degrees 
homie/mqtt-gateway-livingroom/temperature/unit c 
homie/mqtt-gateway-livingroom/$name JaMa Villa MQTT Gateway Livingroom 
homie/mqtt-gateway-livingroom/$stats/signal 54 
homie/mqtt-gateway-livingroom/$stats/uptime 125581 
homie/mqtt-gateway-livingroom/$fw/name mqtt-gateway-livingroom 
homie/mqtt-gateway-livingroom/$fw/version 1.0.0 
homie/mqtt-gateway-livingroom/$online true 
homie/mqtt-gateway-livingroom/MQTTto433/$type switch 
homie/mqtt-gateway-livingroom/MQTTto433/$properties on:settable 
homie/mqtt-gateway-livingroom/433toMQTT/$type switch 
homie/mqtt-gateway-livingroom/433toMQTT/$properties channel-0 
homie/mqtt-gateway-livingroom/433toMQTT/channel-i-2 4462019 
homie/mqtt-gateway-livingroom/433toMQTT/channel-o-1 1394004 
homie/mqtt-gateway-livingroom/433toMQTT/channel-i-1 4461884 
homie/mqtt-gateway-livingroom/433toMQTT/channel-o-2 1397073 

Sample gateway messages:

# sensor temperature reading
homie/mqtt-gateway-livingroom/temperature/degrees 23.70 

Temperature value send form device.

# send RF command via MQTT & response
homie/mqtt-gateway-livingroom/MQTTto433/on/set 1394001 
homie/mqtt-gateway-livingroom/MQTTto433/on 1394001  

First line: MQTT command send from MQTT client or smart home solution. Translates into the code send by the RF transmitter.

Second line: Response from device after RF signal was send.

Config

The following config parameters are available via MQTT message (see Homie documentation how to use):

Parameter Type Usage temperatureInterval long temperature reading interval in seconds temperatureOffset double temperature offset (-/+) to correct the sensor reading. For example, if used in enclosure box, channels const char* mapping of 433MHz signals to MQTT channels, useful if used with OpenHab. All configs can be set during the init procedure of the module or via MQTT messages (see Homie specification).

Sample config:

{
    "settings": {
        "channels": "o-1:[139400];o-2:[139707];o-3:[1398097,1398100];o-4:[139803];i-1:[44618];i-2:[44620];i-3:[44623];i-4:[44638];i-5:[44700];“,
        "temperatureOffset“: -2.4,
        "temperatureInterval": 300
    }
}

Credits

This project is was inspired by 1 Technophile's 433toMQTTto433 solution.