Home Assistant Gree Versati III modbus ESP32

 

Versati III has an interface that communicates via the Modbus software protocol over RS-485 (physical layer standard). RS-485 can between -7 and +12V.

This needs to be converted to TTL, Transistor-Transistor Logic, which operates at low voltages. TTL can be read by ESP32 (not RS-485)

Based on 

https://github.com/peca2345/ESPHome-modbus-heatpump-Gree-Versati-III/blob/main/README.md

Wiring Diagram

Versati_Modbus----RS485--DollatekModule--TTL----ESP32

Hardware

ESP32 NodeMCU Module USB Type-C ESP32 Development Board Dual-Core 2.4GHz WiFi + Bluetooth CH340C for Arduino
https://www.amazon.com.be/dp/B0D8VN3J77?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1

Pinout

https://lastminuteengineers.com/esp32-pinout-reference/

Note that the pinout can be differently ordered.

DollaTek 5 x 5V MAX485 / RS485 TTL Module to RS-485 MCU Development Board

https://www.amazon.com.be/dp/B07DK4QG6H?ref=ppx_yo2ov_dt_b_fed_asin_title

A & B are the connector for RS-485.

DI, DE, RE, RO are the connectors for TTL.

Good article explaining TTL-RS485

https://vault.nimc.gov.ng/blog/esp32-rs485-ttl-converter-guide-1764801490#:~:text=Hey%20guys!,expand%20your%20ESP32's%20communication%20horizons!