I haven’t found a way to wake the esp32 from sleep using the ulp and adc voltage in pin.
anyone have that working?
currently I’m just reading bat voltage in the loop and stopping the send and receive functions and shutting the led and silencing the can interface to not keep the car from going to sleep below 13.5volts. but the esp32 is still running. It looks like going into sleep mode using the voltage level is fairly straight forward using the examples, but I haven’t found a wake example using an adc input.
https://www.espressif.com/sites/default/files/documentation/esp32_technical_reference_manual_en.pdf#ulp
page 659 and 660 show the voltage pin 35 connected to VDET_2 (GPIO35) and can be used by the ulp coprocessor. I haven’t got my head rapped around programming it with the Arduino ide.