BUS Temperature controller

Recently, we need to control the temperature of a dozen boxes, and the idea to make a controller for each box, and adjust/monitoring one by one is not ideal, so we resolve to make a temperature control on a bus based.

The module is to be the more universal and cheap possible, and the ideia to make it usefull and reuseable to use on another projects. Use a single power source (24VDC) to all modules.

Use a 4 wire cable to power and data to control all modules on network.

For the interface we choose RS485 and for the protocol the MODBUS RTU. It´s simple and practical.

This is what we made until now.