Running on single core variant of a chip, but app is built with multi-core support.

[jnorrish]

I have code that runs fine Esp32-Mini-1 Development board. And it runs on one of our custom boards. But we recently did a new custom board and wen I run the same code on the board I get an error.

The error is Running on single core variant of a chip, but app is built with multi-core support.

I am using IDF framework for the development.
The module in all cases is the the ESP32-mini-1. The difference is the marking on the module.
The modules that work are marked with the code DXN4.
The modules that are giving the single core error are marked with the code XXN4.

My first question is what do the different codes mean?

The second question is there a hardware issue that could cause the module to thin it only has one core?

[ESP_igrr]

Hi jnorrish,

Until 2021, ESP32-Mini-1 module was shipped with a single core variant of the ESP32. This changed in 2021 when the module was upgraded to the dual-core version. See this product change notification. Page 4 shows the difference in module markings. Looks like one of the modules is indeed from the earlier batch with single-core chips, which explains this error you are getting.