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RMII pins on a custom board

Posted: Mon Aug 17, 2020 9:10 pm
by pinhead
Hi,

I made a custom ESP32 board with an lan8720 controller to provide ethernet. Using the wifi/lan8720 example in arduino I am able to see if a device is connected but can't communicate with the router.

On closer inspection it seems I messed up and wired the TXD0 pin on the lan8720 to the TXD1 on the ESP32, and similarly the TXD1 goes to the TXD0. Urgh.

Is there a way to reassign the TXD0 and TXD1 pins on the ESP32 ? from what I am finding it seems these are part of the RMII bus which is fixed... :(

Re: RMII pins on a custom board

Posted: Tue Aug 18, 2020 2:55 am
by ESP_morris
Correct, you can't switch the pin without hack your board. RMII signals are all routed by IO MUX, not IO Matrix.