ESP32 Forum

Hello all.
I've still not gotten the hang of deciphering the Pin Functions listed in Espressif datasheets.
Could someone help point me in the right direction/ explain in a little more detail the functions of some of the pins of the ESP32-S3-Pico-1 ?

Specifically the SPI-ish pins, like GPIO10;
RTC_GPIO10, GPIO10, TOUCH10, ADC1_CH9, FSPIIO4, SUBSPICS0, FSPICS0

https://www.espressif.com/sites/default ... eet_en.pdf

Many thanks,
Ben

Hi Ben,

FSPI signals are described in "Table 30-­3. Functional Description of FSPI/SPI3 Bus Signals" of the ESP32-S3 technical reference manual. Other signals like SPI and SUBSPI are used only for connecting SPI Flash or PSRAM, and are typically handled by the low-level drivers (e.g. in ESP-IDF).

Note that if you simply need to use the SPI peripheral, you can use any available GPIO. In addition to the dedicated pins, SPI signals can be freely routed to any GPIO using the GPIO Matrix.

Fantastic, thank you!
I need to start referring to the technical reference manual more! (it's in the name).


Bonus question about pin assignments, which may well be in the TRM;
This appendix from the ESP32-S3 Datasheet shows GPIO0/1/2/3 are enabled for I2C using the ULP.
https://www.espressif.com/sites/default ... 00,1046,76

Would I be able to use GPIO1 and GPIO2 as an I2C pair, leaving GPIO0 and GPIO3 free for bootstrapping?
Or can you suggest another way to use I2C in DeepSleep?

(or have I misunderstood something?)

Many thanks, and Kind Regards,

Ben

Hi Ben,
Yes you can use GPIO1 as the SDA pin and GPIO2 as the SCL pin when using the ULP I2C. You would need to update the i2c_pin_cfg when initializing the ULP I2C - https://github.com/espressif/esp-idf/bl ... _i2c.h#L44