Project for having an MQTT to DMX bridge. This project is tested with the home assistant MQTT light.
This repository exists out of 2 parts: software implementation in Arduino and PCB drawing in KiCad
The software is written in Arduino. The serial registers are written directly. The sofware can be found in the folder 'Arduino/Dmx' Needed library:
- pubsubclient
Before uploading this software, a serial number need to be uploaded in EEPROM. This way of programming gives every arduino a fixed number, without the constant need of changing the software. You can find the way of programming the serial number in my other repository: https://github.com/sgoudsme/Write-EEPROM-numbers.
Fill in the ip, username and password of your broker in the code.
This bridge supports up to 50 DMX channels. Enlarging the buffer size is possible, but I had some unstabilities.
The mqtt topic the arduino connects to is 'D0000/X/command' where D0000 will be overwritten with the serial number, found in the EEPROM and x the channel that need to be changed.
The payload of the MQTT messages should have the following structure:
{ "state": ON, "brightness": 127, "transition": 5 }
with: state is ON or OFF, the brighness is a value between 0 and 255, the transition is a value in seconds
The hardware drawing is made in Kicad V5. It simply contains a footprint for an arduino and a MAX485. Also some extra pins are exposed, when I would need some small button. This is not used for the moment. The MAX485 is connected to pin D1. A regular ethernetshield (W5100) is also needed for the MQTT part.
The plots are found in the folder "plots", and the PCB's are ordered at JLCPCB.
At the moment of writing, the PCB's are in production, so I haven't tested them. The circuit is made on a breadboard and should be working.