Andrey Klimov

LightHub — Developer Documentation

LightHub is a flexible open-source smart-home controller firmware for Arduino Mega 2560, Arduino Due, ESP8266, ESP32 / ESP32-C3, STM32, NRF52840 and M5Stack.

Links:

What is LightHub?

A microcontroller-based smart-home hub that exposes every physical channel as an MQTT-addressable “item” (virtual channel):

myhome/in/<device>/<item>[/subitem]/<suffix>   <- commands
myhome/s_out/<device>/<item>[/subitem]/<suffix> <- status

24 channel types (CH_*, 0..23): DMX dimmers, PWM, relays, groups, thermostats, PID, Modbus (dimmer + universal master), Haier AC, NeoPixel strips, motorized gates, UART bridges, relay-PWM, multizone ventilation (VENTS), elevator, counters, humidifier, Mercury energy meters, sprinkler controller.
Inputs: buttons with single/double/triple/long-press detection, analog inputs with map transformations, rotary encoders with profiles, DHT22, CCS811, HDC1080, 1-Wire.
Buses: Modbus RTU, CAN (50 kbit/s, non-IP “lightspot” controllers), IP-Modbus gateway, UART bridges, 1-Wire (DS2482).
Integrations: Home Assistant, OpenHAB, Node-Red, HomeRemote; Homie discovery topics; OTA updates; JSON config from server or via web/CLI.

Doxygen API reference

The complete API reference for the firmware source is published under doxygen/.

Highlights:

item.h — items (virtual channels), channel types, suffixes
itemCmd.h — command set and command codes
inputs.h — input types (buttons, sensors, rotary encoder)
candriver.h — CAN protocol (datagram format, payload types)
config.h — config load/save, ETag, MAC
modules/out_*.h — one driver class per channel type (JSON config format, handled commands, published status topics)

Building

git clone https://github.com/anklimov/lighthub
cd lighthub
pio run -e <target>          # due | mega2560 | esp32-wifi | esp32c3-wifi |
                             # lighthub21 | nrf52840 | stm32 | ... (16 targets)

Precompiled binaries for all targets are attached to the GitHub releases.