What is it?

This PCB takes 7.5 V to 36 V input and A+ and B- from a Modbus RS485 serial link and pass it on to the SiPy, LoPy4, Gpy and FiPy chips from pycom.io. This allows you to communicate to and from MODBUS RS485 to NB-IoT, Sigfox, WIFI, LoRaWan or Bluetooth as supported by the pycom.io chip you decide to plug into the thing.

I will provide a sample code for up and downlink messages via Modbus RS485 to LoRaWan in Micropython, if you have other requirements look at the pycom docs for details.

Modbus is a messaging protocol that defines the packet structure for transferring data between devices in a master/slave architecture. The protocol is independent of the transmission medium and is usually transmitted over TCP (MODBUS TCP) or serial communication (MODBUS RTU). Have a look at for details micropython modbus

Why did you make it?

The reason this was made was my inability to get an off the shelf RS485 to LoRaWan bridge solution to work.

What makes it special?

There is no reason this PCB is special, it takes 7.5 V to 36 V input and A+ and B- from a Modbus RS485 serial link and process on a SiPy, LoPy4, Gpy and FiPy chips from [pycom.io]. This allows you to communicate to and from MODBUS RS485 to NB-IoT, Sigfox, WIFI, LoRaWan or Bluetooth as supported by the pycom.io chip you decide to plug into the thing.

You get the PCB with 7.5-36V to 5v power supply, 4 Pin Plug in Screw Dupont Cable Terminal Block Connector Right Angle to connect VIN, GND, A+ and B-, Headers for the pycom chip and RS485 Module Hardware Automatic Flow Control Module Serial UART module.

Units come fully soldered and assembled. Chip from [pycom.io] not included.