Dylan, If I understand you correctly, you are looking for confirmation that with the ESP32-S2: 1) When the ULP wakes up from sleep, it has to re-initialize all the pin settings? 2) Re-initializing the pin settings after ULP wake-up works the first time but not for subsequent wake-ups (the pins are b...

Hi ESP_Sprite, That documentation was easy to find but wasn't explicit about how to program the ULP in C especially accessing the SDK functions and registers, however from running this sample https://github.com/espressif/esp-idf/tree/master/examples/system/ulp_riscv and updating it was easy to concl...

All, From the S2 IDF SDK: "The main difference from the FSM ULP is this variant can be programmed in C using standard GNU tools" Can someone explain exactly how to program and compile in C the RISC-V based ULP versus the main Tensilica core. Can all the SDK C commands be treated the same way as we w...

Is there any more information on programming the S2 RISC-V ULP, as Andy mentioned in this thread the IDF documentation isn't helpful to understand how to use the ULP, some examples of common functions would be useful.

Or do we just assume its exactly the same as the non S2 ULP?

Thanks for the help.

I had a similar problem with the Pico, and solved it by ensuring the decoupling capacitors were placed close to the chip and was very careful with the earth under the chip so that only current destined for the ESP32 was routed via the ground pad, so no other transient current could interfere. My boa...

The new board looks to be OK, the problem was the peripheral connection.

Lesson here - even though the PICO is a module on chip it still needs careful attention to PCB layout and decoupling.

Thanks for the help.

Hi Alvin, About to head back to work from vacation. I did get this working by doing a different PCB layout and paying a lot of attention to decoupling, ground and layout, and I can get it booting now but not when I attach a peripheral to the GPIOs (won't connect with the programmer). I'll continue d...

Should be clean due to the RC filter but I will check it (I have another board coming with a better layout, as I suspect the problem is eddie currents in the groundplane).

I don't understand - if the reset signal is before the resistor then it will be constantly tied to Vcc. The schematic as drawn will have EN/RESET high except for the RC constant during power up, and when the reset button is pressed, will go low to reset the MCU. This is consistent with the PICO D4 d...

Good idea, will try that