Issues with PicoCoreMX6UL-V4 - GPIO_J1_29

  • Hi,
    we´ve ordered a starterkit of version PCoreMX6UL-V4. I´m trying to switch the GPIO_J1_29, but it doesn´t work. If I take a look in the GPIO Reference Card, I have to export GPIO 135.

    1st I was wondering why in the GPIO Reference Card it is written the pin can be used by J10-24. If I download the PcoreBBRGB-REV120-Schematic.pdf it is J9-24. So I think there is something wrong, either it should be J9 or J10.

    Here my steps to reproduce.

    1. Unpack PCoreMX6ULL-V4 starterkit
    2. Plug power supply and debug interface
    3. boot into linux and login
    4. export GPIO 135, "echo 135 > /sys/class/gpio/export"
    5. Setup GPIO direction: "echo out > /sys/class/gpio/gpio135/direction"
    6. Switch GPIO to 0: "echo 0 > /sys/class/gpio/gpio135/value"
    7. Switch GPIO to 1: "echo 1 > /sys/class/gpio/gpio135/value"
    • If I measure on J9/10 - Pin 24, I didn´t see any change. It is always 0V.

    Any hints what I missed?

  • DetectiveDuck

    Changed the title of the thread from “Issues with PicoCoreMX6UL - GPIO_J1_29” to “Issues with PicoCoreMX6UL-V4 - GPIO_J1_29”.
  • Hello and welcome to the forum,

    You are right there seems to be a mistake in the GPIO Reference card and the PcoreBBRGB-REV120-Schematic.pdf.

    The feature connector in the schematic should be named J10 as stated in the…ore/PicoCoreBBRGB_eng.pdf

    J10_24 is connected to GPIO4_16 on the PicoCoreMX6ULL sinc revision 1.1, so please try to export GPIO 112.

    We will correct both documents right away.

    Thank you for the hints

    Your F&S Support Team

  • Hello,

    i get this information from the…oreMX6UL_Hardware_eng.pdf.

    Page 8 shows, that J1_29 is connected to NAND_DQS.

    If I check the pad settings for this pin in the Linux kernel I see, that this pin can be muxed to GPIO4_IO16 which should map to GPIO 112 ((GPIO_BANK-1)*32+IO_NUM)…dts/imx6ul-pinfunc.h#L806

    J1_29  was connected to GPIO5_IO07  in Boardrevision 1.0. This changed starting Boardrevision 1.1 but the GPIO Reference Card is not correctly updated at this point.

    Please excuse the inconvenience, we are currently checking the reference card for further mistakes.

    Does it work for you with GPIO 112 ?

    Your F&S Support Team