ESP32 Forum

Hi all,
I'm doing a design in a custom PCB including the ESP32-S3FN8, and I have some questions about the usage of certain pins, concretely the 32, 33, 34 and 35. Theorically, according to the datasheet, these pins are used by the flash in package.
But can we also use these pins for another thing? And in this case, can we use this pins as GPIO at the same time that the flash in package is being used?

No. On the S series chips, with ESP-IDF as it is right now, it's not possible to use the flash pins for anything else. (Theoretically you could connect another SPI device to it, but software support for that is hairy so ESP-IDF does not support that at this moment.)

Hi,
Firstly, thanks for the answer!
Anoter question related to this... We have the ESP32-S3FN8, which does not have In-Package PSRAM.
We want to use the GPIO26 (SPICS1), which according to the datasheet is used for In-Package PSRAM. As we do not have, it should be that easy to use as a normal GPIO, shouldn't be?
But when we configure this GPIO it does not work. Do you know why?

It should, indeed. How are you configuring that pin? Does gpio_reset() help?

We are using these functions to configure the GPIO:
gpio_reset_pin(GPIO_NUM_26);
gpio_set_direction(GPIO_NUM_26, GPIO_MODE_OUTPUT);
And the, we put the GPIO to '1', but always stays in '0':
gpio_set_level(GPIO_NUM_26, 1);

We tried some other GPIOs and they work fine

Strange. You're using the chip itself, and not a module?

Yes, we are using the chip itself, concretely the ESP32-S3FN8