Two concerns: WS2812B expects 5V logic on the data line, but the ESP32 GPIOs only provide 3.3V. Since 3.3V is around the WS2812B high value cutoff, sending 3.3V signals to the WS2812B will sometimes work and sometimes not work, and it can go between working and not working with little warning. You s...

Which board are you using? Some boards, like the ESP32-S3, only have 4 TX and 4 RX channels.

Does it help if you mark the global variable as volatile?

The header block and pin layout description for the ESP32-C3-DevKitM-1 suggests that GPIO19 is connected to D+, which is connected to the CP2102N USB-UART bridge, which may have its own pullup for that line (unclear from the CP2102N documentation). If that is the case, the pulldown on the ESP32-C3 w...

Sven, this inverted F antenna design is not new and is rather widely used. There are a couple benefits to using this type of antenna: It is a small antenna compared to many other designs, which is great for a PCB antenna and for creating small IoT devices. The antenna is nearly omnidirectional in 3D...

we configured the pins as input pins and tried to read the pin status using the ESP IDF read function, gpio_get_level(). If you are not initializing the pin through gpio_config(), try a call to gpio_reset_pin() before setting the pin direction and reading the pin. Some pins are not connected to the...

@ESP_Sprite, any chance the documentation for gpio_set_direction() can be updated to note this behavior? It is very unintuitive that gpio_set_direction() does not always result in an input or output pin. There is already a note under gpio_reset_pin() , but I would not think to do a "reset" for pins ...

Are you measuring the output on your scope? In the off chance you are using gpio_get_level(40), that function will always return 0 if the gpio is set to output. Otherwise, from what I can see, Arduino's pinMode() makes a call to gpio_config() , which does a few more things than gpio_set_direction() ...

There are some schematics in the datasheet. See chapters 5 and 6.

The internal pullup on GPIO0 is reenabled during every chip reset. It is unclear from your description: are you resetting the pin state every time you press the button and restart the ESP? What version of Arduino are you using? Old versions of Arduino did not alter the pullup/pulldown state when pin...