Alternative Modbus Gateway Solution

[Waz-Cpt]

Hello Everyone,

I was playing around with alternative ways to communicate with the KellerZa integration over the long weekend.

I have been thinking that there must be a way to use an ESP32 as a modbus gateway device.

I stumbled across the following project.

https://github.com/zivillian/esp32-modbus-gateway

It works really well, I will be forking it as there are some tweaks I am working on. Need to enable the change the code to factor in use of the ethernet port instead of the WiFi. I would like to see if I can rework it to be used as a custom component in ESPhome. I suspect that with some effort you could get newer ESP32 module to run two RS485 modules

What is important to know is that youe RS485 to UART/TTL device needs to have Automatic Hardware Flow Control. This is not found on many of the devices.
This is the converter I used:
https://www.prototypediy.co.za/product/ttl-to-rs485-module-serial-port-uart/

The other option is to use a newer ESP32 S3 DevKit C which support USB on the go and then rework the code to use that with a USB RS485 device. Have not played around with that as yet.

I have set this up currently with a LilyGo T-Ethernet-PoE unit and powering of PoE but using Wifi.

I understand that there are also cost effective Modbus gateways out there. Probably work out to a similar price of the hardware I used. But this could be done with a far more affordable ESP32 module and stepdown voltage converter to power it directly from the inverter.