IoT Home Controller

This project is a Python-based Internet of Things (IoT) application. It started as a hobby project for home automation system that uses a Raspberry Pi as a gateway. The Raspberry Pi is connected to a 433Mhz RF module and a USB-to-serial RS-485 adapter. The RF module is used to control RF-based devices, such as remote switch buttons. RS-485 adapter is used to control ModBus-based devices.

The main work flow when I switch ON/OFF lamp via a remote switch:

1. The RF module (connected to RPi) receives a signal from a remote switch (microservice rc-mqtt) and publishes the signal in MQTT with topic "rc_code" and RC code as the payload (e.g. {"rc_code": 12345678}).
2. The MQTT subscriber (microservice mqtt-sub) receives all messages (not only from rc-mqtt) and post them to the Django via API.
3. The Django get raw message from mqtt-sub, parse it, and if found a match, it will perform an action and send command to last microservice hw-ctrl. Example, if we turn ON kitchen lamp, Django found record like 0123456789 (RC code) is relay number 1 and unit number 2 (kitchen lamp connected) and make http request /relay/1/1/?cmd=on to hw-ctrl.
4. The hw-ctrl microservice receives the request, parse it and send command to the relay (if it commands to relay) via ModBus protocol. Now service hw-ctrl is able to control the relay (set in get state) and some type of sensors (get state).

Commands from RC switches - its only one way to control devices. You can send commands directly to MQTT, example it can be web interface like Node-RED or Home Assistant. I added support for Alice assistant (Yandex) and you can control devices via voice commands (its really cool).

A little bit about hardware. As I said, the heart of the system is Raspberry Pi. Important part of project is relay, I use chipper relay boards from AliExpress like this:

16-Channel 12V 10A Board RS485 Modbus RTU Relay Module

16 Input 16 Output RS485 Board Modbus RTU Module

Remote switches - I use 433Mhz transmitter:

433MHz Universal Wireless Remote Control Wall Panel RF Transmitter

Beside ModBus devices service support some type of sensors, like DS18B20, BH1750, BME280, BMP280 & etc., connected via I2C or Wire1 bus, support devices you can see at hw_ctrl.py. I use sensors for monitoring temperature, humidity, light, etc.