I've verified this experimentally and it does actually work. I'm able to detect an I2C device and read registers, even while using the serial monitor. I assume that sending bytes via the monitor could cause issues, but I don't plan to be doing that in my use case.

I have a device with a large number of connections, and I'm trying to conserve as many GPIO pins as possible.

Would it be safe to use GPIO0 and GPIO3 with the I2C or I2S peripherals? I know these pins are needed by the serial bootloader, but they aren't needed once application code is running, right?

Yes, I think you're right that this is a variant of those bugs. Just for one more data point, what ESP-IDF version are you using? I'm using a fork of v3.3. It is just v3.3 with two commits backported onto it from: https://github.com/espressif/esp-idf/issues/3592 Here is the exact branch that I am u...

@ESP_Angus, do you think this is due to the PSRAM cache issue reported here: https://github.com/espressif/esp-idf/issues/2892 Looking around, I found a similar report of string corruption here: https://github.com/espressif/esp-idf/issues/3006 I'm also noticing that I can't repro the issue if I use M...

OK, it looks like I can get this to recur pretty frequently when I put the device under a lot of load. This code is part of a loop that copies incoming MQTT messages into a destination buffer, up to 32 bytes at a time. This time, the out buffer started with 611 bytes of data, zero-padded to 1024 byt...

There is definitely no overlap. I also tried replacing memcpy with memmove and hit the same issue.

This actually only occurs intermittently. I'll try to catch it in debug mode again tomorrow and I'll post the affected memory addresses.

Has anyone else run into an issue with memcpy somehow replacing bytes with null characters? I seem to be "losing" bytes during a copy. For example, I have a zero-initialized buffer with a capacity of 512 bytes, with 390 bytes filled with non-null data. I attempt to copy 32 additional bytes onto the ...

In case anyone else is wondering whether the EEPROM is at all necessary, it's not. I physically removed it from my ESP32-WROVER-KIT and everything still works as expected. So if you're building a similar system, feel free to omit the EEPROM entirely.