Originally posted by **GR8Dane604** November 19, 2021
Thanks for this awesome project! I'm finally making the plunge into programming microcontrollers and using the ESP32 and this will be my first project.
I'm wiring up the cable now, and stuck on [connecting the Tracer to the MAX485](https://github.com/Bettapro/Solar-Tracer-Blynk-V3/blob/v3.x.x/docs/Esp32_max485_epever_rj45.md#max485-module---epever-controller-rj45) and wondering if anyone can clarify which Ethernet pinout standard was used for this step? [T568A or T568B](https://www.comms-express.com/infozone/wp-content/uploads/2017/01/T568A-and-T568B-wiring-spec-standards.jpg)? I'm getting confused on the _Ethernet green, pin 5 ->_ I'm assuming that's the green wire in the cable, and mine use the T568B standard meaning it's green is pin 6. That would be pin 2 using the T568A standard. Neither cable standard uses pin 5 for green, so maybe that's the ESP32 pin? A and B are on the MAX485, but does it need to go to the ESP32 pin 5 as well? I've terminated a bunch of ethernet cables in my day, so maybe I'm over complicating things. I've got an Epever official modbus cable, but that doesn't seem to match-up either. Thanks in advance for any assistance.
> MAX485 module <-> EPEVER CONTROLLER (RJ45)
> Cut open your ethernet cable and split out pin 3, 5, 7 (B, A, GND). Refer to Tracer Modbus PDF for additional info.
>
> Connect cables as follows:
>
> Ethernet green, pin 5 -> A
> Ethernet blue, pin 3 -> B
> Ethernet brown, pin 7 -> GND on module and EPS32 GND pin - -> to prevent ground loops - important!
> DON' T use pin 1 or 2 to feed the ESP8266 (they supply 7,5/5V - 50mA maximum)
Discussed in https://github.com/Bettapro/Solar-Tracer-Blynk-V3/discussions/25