ESP32 Forum

Posted: **Fri Feb 11, 2022 5:36 pm**

Hi,

I have an ESP32-PICO-D4 chip and a very simple Arduino that toggles its pins using

digitalWrite(pin, HIGH/LOW);

I can toggle different pins, no problem, but specifically pin no.25 which the datasheet reports as
Name: IO16
Functions: GPIO16, HS1_DATA4, U2RXD, EMAC_CLK_OUT

doesn't work. Any ideas why?

I simply use

Code: Select all

pinMode(16, OUTPUT);

and

Code: Select all

digitalWrite(16, HIGH);

which works for all other pins.

Posted: **Sat Feb 12, 2022 6:24 am**

Potentially because according to the datasheet:

Pins IO16, IO17, CMD, CLK, SD0 and SD1 are used to connect the embedded flash, and can not be used for
other purposes. For details, please see Section 6 Schematics

Posted: **Mon Feb 14, 2022 5:27 pm**

Even though the datasheet says "Notice:", I didn't notice that!

Thank you

ESP32 Forum

Pin #25 - GPIO16 doesn't work on ESP32-PICO-D4

Pin #25 - GPIO16 doesn't work on ESP32-PICO-D4

Re: Pin #25 - GPIO16 doesn't work on ESP32-PICO-D4

Re: Pin #25 - GPIO16 doesn't work on ESP32-PICO-D4