ESP32-POE-ISO WROVER I2C GPIO16 <-used by PSRAM, Pin List?

Started by daabutts, February 09, 2024, 08:37:54 PM

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Quote from: LubOlimex on February 02, 2024, 08:48:13 AMDoubts ESP32-POE-ISO Wrover

In trying to get I2C to work, I found a little note on the quote above that indicates that GPIO16 is used for PSRAM.  I2C is normally on SLC=GPIO13 SDA=GPIO16.  I tried all kinds of things, and searched forever before I found this.  I moved SDA to GPIO32 and it works fine!

#include <Wire.h>
void setup() {
 // Wire.begin();
   Wire.begin (13, 32);  // Can't use GPIO16!!!!!

I have the file from Olimex ESP32-Poe-ISO_Rev_L.pdf, but I don't see this noted.  It took me quite a while to find the -ISO ETH settings as well (see quote below).  It would be nice to have complete examples on the Olimex website for each version of the boards.  Specifically, Rev L WROOM and Rev L WROOM.
Quote from: daabutts on February 07, 2024, 05:58:51 PMESP32 / Re: ESP32-POE-ISO ESPHome: wrong chip ID
Is there a better, complete, all in one place, source of information for the ESP32-POE-ISO WROVER that lists what pins are used and what are available?



When WROVER module (instead of the default WROOM) is used then GPIO16 and GPIO17 are unavailable (both are used for the PSRAM inside the module).

In that case we have set GPIO33 to go on UEXT1 pin #5 (instead of GPIO16).

Also the clock for the Ethernet is now GPIO0 (instead of GPIO17).

This requires software modifications in case you've used GPIO16, GPIO17 or related functions (I2C, Ethernet) previously.

This is visible in the schematic in this part:

Technical support and documentation manager at Olimex