Toggling of GPIO4_IO23 on humming board pulse

NXP i.MX8M Plus
1

Hi,

I want to toggle the gpio pin 119 attached in screen shot. But not able to toggle when i see on oscilloscope/multimeter. Can you please correct me if i am wrong?

I followed the below steps to toggle it.

  1. echo 119 > /sys/class/gpio/export
  2. echo out > /sys/class/gpio/gpio119/direction
  3. echo 1 > /sys/class/gpio/gpio119/value
  4. echo 0 > /sys/class/gpio/gpio119/value

Thanks,
Kartheek

Screenshot from 2023-10-09 19-03-38
Screenshot from 2023-10-09 19-03-381565×727 133 KB

2

What BSP image are you running?

3

Hi

Please see the metioned screen shot for Linux BSP version. And i have followed the steps mentioned in link for yocto

Thanks & Regards,
Kartheek
Screenshot from 2023-10-10 15-03-43

4

and what revision of the carrier are you using? The pin connected to the mikrobus changed between rev 2.3 and rev 2.5 carriers

5

May i know how to find the rev. I have rev 2.2, 2.3 & 2.5 downloaded from this link. And we are following rev 2.5.

6

You should be able to check the SKU, but otherwise it is silk screened onto the board underneath where the SOM is mounted.

7

Unable to find the rev. Attached board underneath image for your refernce. Can you please help me.

MicrosoftTeams-image
MicrosoftTeams-image1860×2462 665 KB

8

It is on the top of the board in between the SOM connectors. You need to remove the SOM to see it.

9

Hi Jnettlet. Sorry for late response. My humming board pulse(imx8mplus) is rev 2.5.
Can you please tell how to toggle gpio on mikrobus.

10

Rev 2.5 has the SAI2_RXD pin connected to SAI3_RXD of the iMX8MP SOM. This pin is also shared with the wm8904 audio so they can’t be used at the same time. To use this pin as a GPIO you need to remove it from the &pinctrl_sai3 group and add it to the &pinctrl_hog group as a GPIO. It should be GPIO 158.