This is the driver I ported and extended:

https://github.com/MartyMacGyver/ESP32- ... ED-Drivers

As for the interrupt allocator info, a search shows it moved here:

https://github.com/espressif/esp-idf/bl ... _alloc.rst

I added an oled display and an arduino to my I2C setup to generate some traffic. While testing some changes to make things faster I ran into issues with unreliable communication. Errors will pop up several times a day, causing my reboot logic to trigger. Please update to the latest Arduino-ESP32 - ...

I've also tried it with a borrowed arduino Due and it also works. That Seeed-Studio repo you're based on is rather ancient... I just tried the Adafruit PN532 library ( https://github.com/adafruit/Adafruit-PN532 ) and with a few small modifications examples/iso14443a_uid worked fine on both Particle...

I've got no idea why this would be failing, but as I'm curious about the tech in general anyway I ordered what appears to be the same one from Amazon. I'll have it on Monday and can delve into it then.

I don't have one of these boards (yet)... it'd take a few days to get one here. Is it specifically the HiLetgo one you linked to? Version 3 or something earlier? What GPIO pins are you wiring to what pins on the board? Where's your code? Are you using the latest Arduino-ESP32 as well as latest Ardui...

mvrhov wrote:Well even with the latest patch I2C still doesn't work with PN532 boards. e.g ones like this

It doesn't work at all or has glitches? Does that device work with any other Arduino-type device you have?

: I have a normal SSD1306 display that works utterly fine on other MCUs, but glitches to the point of being non-functional on the ESP32 Someone else has reported that this fix stopped their SSD1306 from glitching . So it's possible the clock speed/waveform itself was a red herring. Although we'll c...

This I2C thread is the result of one problem: I have a normal SSD1306 display that works utterly fine on other MCUs, but glitches to the point of being non-functional on the ESP32. That led me to examine the I2C frequency (very sensitive and inexact), the waveform (the 50% duty cycle is naive and ma...

Note that the change was made and merged into Arduino-ESP32 pretty quickly. Not sure what the state of esp-idf is though.

Hans, Others have been having this problem as well and I shared your post with them. Thanks to your discovery, the problem may be resolved. An issue has been raised on Github regarding this: https://github.com/espressif/arduino-esp32/issues/286 . You might want to subscribe to that issue on there to...