Xiao ESP32-C6 GPIO21 (D3) always HIGH?

[volkerforster]

Hi,
I have a problem with a brand new, never before used Seeed Xiao ESP32-C6. I tried to establish a SPI connection with an Atmega2560 (level converter in between) and I had no luck. I tried all different SPI modes and speeds down to 250kHz. Nothing.

Then I tested every single SPI pin: changing the level on the Atmel pins and reading the level on the ESP pins. I was surprised to find out that GPIO21 (D3) on the ESP32 always reads HIGH level. Even if I pull the pin down to GND, it still reads HIGH.

Is my Xiao bad? Or did I overlook something? According to the schematic, the pin is not connected to anything inside the Xiao.

[ESP_Sprite]

As far as I can see there's nothing special about that pin. Could be a defective board indeed.

[volkerforster]

Indeed, it seems defective. I tried other ESP32-C6 modules and their GPIO21 behave as expected.