Docs are here .

Section 7.1 of the TRM:
The ESP32-C6 chip features 31 GPIO pins. Each pin can be [...] connected to an internal peripheral signal. [...] peripheral input signals can be from any IO pins, and peripheral output signals can be routed to any IO pins.

You don't want to use any of ...

When I looking for the i2c peripheral pins in some esp32 modules, I couldn't find anything in espressif website. Turns out all the gpio pins can be used as i2c. Is that true? I'm going to design my custom board, and I don't want to change the pins later.

Just configure each interface to use the pins you want, see e.g. here.

Does that mean I can use any pins for any peripherals?

I'm using esp32-c6 for my project and I need to use all the peripheral such as UART, I2C and SPI. But I can't use I2C and SPI together because they share the same pins. How can I solve this problem?

Yes, you can. Either program the STM as a passthrough device (so anything on the PC can talk to the ESP directly) or you can use esp-serial-flasher.

Thanks you. That explained what I need to know

I connected my esp32-c3 module with my stm32 microcontroller via UART. My question is can I flash or upload my firmware through UART not USB because I already have USB for stm32 and it would be better if I can use just one USB for both stm32 and esp32.

Esp32-c3 is only used for wifi and bluetooth ...

Option1:
https://github.com/espressif/esp-at#esp-at-support-policy-for-esp-chip-series
Option 2 (not sure if there is version with C3):
https://www.u-blox.com/en/product/nina-w10-series-open-cpu
https://github.com/arduino/nina-fw

Thanks you for your reply. Second option is to use NINA instead of ...

Hi, I want to use stm32 with esp32-c3 as wifi and bluetooth module. When I search the development boards with wifi module, I didn't find any boards that used esp32 as wifi module, instead they used other modules from other manufactures. I want to make mobile robot controller with STM32 and ESP32-c3 ...