I'm trying to trigger a picture using the GPIO13 of an esp32-cam, AI Thinker model. I'm using that example as a base: https://randomnerdtutorials.com/esp32-cam-pir-motion-detector-photo-capture/ but instead of the PIR/Transistor combination, I'm using a press button with a pull-up resistor that pulls the GPIO13 pin down when pressed, simulating the PIR signal. I'm feeding the esp-32 cam with a 5V power supply and the button circuit with the 3.3v pin of the esp32, all grounded. All hardware, SD card and so on is tested ok, I got the right voltages and I can see the GPIO13 Pin going to ground on my scope, but I just doesn't work. Any ideas? Edit 1: I'm using the ESP32-CAM-MB USB Board
This may or may not be a problem, as the state of
GPIO13 is only relevant for sleep/wakeup when the chip is sleeping, and only relevant for SD card access when the chip is running; but there is an external addon: your pullup resistor on the button is still there when the chip is running. The PIR module from the tutorial that you're trying to replace probably has an open collector output (floating when inactive, pulled LOW when active).
My best hunch is to get rid of the pullup resistor on your button, so that the pin is floating during SD card access.
There still is the possibility that you then interfere with the SD card data when you keep the button pressed. If that is the case, you may need to put a resistor in series with the button, so that the wake-up signal is weaker than the SD card data signal (start at 100KOhm and reduce until wake-up works).
If that isn't it, the question is lacking details. As you did not even post a description of what exactly "just does not work", first thing would be to produce a minimal sketch just to test sleep/wakeup via GPIO13 and post that here.