GPIOs 18 and 19 are the ones the USB peripherals use.
If you use pinMode on them, you are basically making them behave as normal GPIOs, therefore losing the USB functionality.

I would recommend having a look at the RMT peripheral. I am pretty sure you can configure it according to your needs.

We got around 10 of them assembled and none of them work, so that doesn't seem to be the problem. For the power supply, we are just using a 3V3 LDO (XC6206P332MR) which should be more than enough for this application. About the exposed flash pins, as can be seen in this picture, they all are literal...

Hello, I just noticed we don't have the 10uF decoupling capacitor that is present in the "ESP32-PICO-KIT V3" schematic 3.3V rail.
We weren't going to use WIFI/BL at all so we ended up removing it to save board space.
Do you think that could be the reason the upload fails?

Those pins are not connected to anything else.
Any ideas on what else might be going wrong?

Hello, these pins have been left unconnected:
- IO6 (31) (CLK)
- IO7 (32) (SD0)
- IO8 (33) (SD1)
- IO9 (28) (SD2)
- IO10 (29) (SD3)
- IO11 (30) (CMD)

The datasheet also mentions IO16 and IO17 but those are not exposed in the PICO-V3 package.
Is there any other FLASH pin that we are missing?

Hello, we are transitioning a design from a ESP32-WROOM to a PICO-V3. Unfortunatelly, when trying to program the new custom board with the PICO-V3, the flashing procedure fails half way through. When starting the ESP in the normal way, this is outputted from the UART port: rst:0x10 (RTCWDT_RTC_RESET...