I'm not familiar with your board, but if it's like the Espressif ESP32 Core Board, the auto-programming is handled by two transistors hooked to the RTS and DTR lines of the onboard USB to serial bridge IC. Have you verified that the DTR and RTS lines are toggling when you attempt to flash? If not it...

Ok, I feel stupid now. It occurred to me that the printf and log stuff might be a problem in the ISR, so I commented them out. Turns out I missed one.
I commented this last one out and now it works without crashing. Thanks!

Here is the output of make monitor after the crash: 0x4008216f: lock_acquire_generic at C:/esp-idf/components/newlib/locks.c:141 Backtrace: 0x40086184:0x3ffc01c0 0x40086283:0x3ffc01e0 0x4008216f:0x3ffc0200 0x4 008228d:0x3ffc0230 0x400d4ede:0x3ffc0250 0x400d8119:0x3ffc0560 0x40081e35:0x3ffc 0590 0x40...

I have a project using the ESP32's PCNT peripheral to count pulses from a sensor. I don't have the sensor yet, but I'm trying to simulate sensor values with a function generator set to 50% duty cycle and 3.3V square waves. When I switch from the 2 KHz scale to the 20 KHz scale, or 20 KHz scale to th...

THANK YOU SpenZerX for posting that code! I was tearing my hair out trying to get that PCNT peripheral to clear its counter.

Espressif, please get this fix integrated into the ESP-IDF.