Is it possible to have a self-healing esp-wifi-net in which each node also offers a wifi AP, so that all devices (phones, laptops) that join through one of the esp32s in tge mesh are placed in a local area network and can communicate with each other?

I second this.

Even better, there should be load balancing across multiple routers

there seem to be different ways to do mesh networking with ESP2866 and ESP32 and I'm a bit confused currently. There seems to be ESP-WiFi-Mesh (https://www.espressif.com/en/products/sdks/esp-wifi-mesh/overview) and there is ESP-Mesh (https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-gu...

Is it valid to write (without reading back) to PSRAM while within an interrupt?

My code works, I'm just not sure if it's well-defined/legal or not.

I just noticed that the released Arduino framework has been compiled as Debug build.

After compiling it myself as Release build, my app runs a lot faster.

Is this an oversight or is there a reason for this?

Does that mean there's currently no automatic handling of this and if more than 4MB of external ram should be used then one needs to meticulously map and unmap the ranges used by hand?

I have a ESP32-D0WD with 8MB of external ram. When I run my program, this is the start of the output I get: [0;32mI (621) boot: Disabling RNG early entropy source...␛[0m ␛[0;32mI (621) psram: This chip is ESP32-D0WD␛[0m ␛[0;32mI (626) spiram: Found 64MBit SPI RAM device␛[0m ␛[0;32mI (631) spiram: SP...

but functions like __atomic_load_8 could still be implemented using semaphores - so just because the hardware doesn't support it doesn't mean the functionality gotta be missing from the library

Can you post the error and decoded call stack?

Where can I read about these attempts?