Free/Available GPIO PINs Question

  • I've been trying to see what pins are useable/free on the major revision (Core1, Core2, CoreS3) versions of pinouts, and I have a few random (should be easy to answer) questions:

    1] GPIO 10 on the CoreS3 - is it used? I couldnt find it on the schematic. It's used in the Core1/Core2 products for Flash write-protect, but cant see anything on the CoresS3 - is it free? Found it

    2] GPIO 22 through 27, and GPIO 32 for the CoreS3 - same thing - Are they used? I can't find them referenced in the schematics, although they are -all- used on the Core1 and Core2 (except for GPIO 24 which seemingly isnt used by anything) GPIO 26 and 27 are available

    3] GPIO 20 on the Core1 and Core2 - Are they USed? Used by USB

    4] GPIO 28 through 31 - are they used on any product? No

    5] GPIO 40 through 48, on Core1 or Core2 - Do they exist? I know they are used for a Camera interface on the CoreS3 Only exist on CoreS3, used by camera interface (gpios 38 through 48)

    6] GPIO 19/20 on the CoreS3 - they are used for something with USB? Yes

    Thanks for any help!strikethrough text

  • This is what Ive been able to put together from the (often conflicting!) Documents and schematics. Probably has several mistakes, but then so do the docs and schematics :/
    Several question marks remain though.

  • Hello @mtylerjr

    for ESP32 (Core1 / Core2) have a look here:

    3] GPIO20 doesn't exist.
    5] last GPIO is 39; so no, GPIO40 to 48 do not exist.

    And for ESP32S3 see here:

    6] yes, GPIO19 / 20 are connected to the USB connector.


  • For Core1, Core2, and CoreS3 versions, GPIO 22-27 and GPIO 32 are free. GPIO 20 on Core1 and Core2 is used. GPIO 28-31 are unused. GPIO 40-48 are not on Core1/Core2 but are used for Camera on CoreS3. GPIO 19/20 on CoreS3 are used for USB.

  • Thanks for the replies