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Cannot get output on MIO pin on Picozed 7030 board

mubashirazaman

I found out from the PicoZed 7015_7030_User's Guide that the 1st and 2nd pins of JX2 are basically MIO 10 and 13 respectively.

Now the zynq_gpio basically starts from gpiochip906 that is the 0th pin of gpio is at position 906, and as i want to access the 10th pin that is JX2.1, so I used the following commands in the linux terminal.

root@picotry2:/sys/class/gpio# echo 916 > export
root@picotry2:/sys/class/gpio# echo out > gpio916/direction
root@picotry2:/sys/class/gpio# cat gpio916/direction
out
root@picotry2:/sys/class/gpio# echo 1 > gpio916/value
 
The logic behind me using 916 is that if the 0th pin is at 906 so the tenth pin of MIO will be at 916. But the problem is that when i check the output in the multimeter, JX2.1 is not showing significant voltage, it just shows 0.04 V.
 
I have also attached two extra gpio modules in the block design. The first one starts from gpiochip 897 and the second one starts from gpiochip 902.
 
Can anyone please give me a suggestion as to what mistake i am making?
  • 0

    Hi Mubashira Zaman,

    If you take a look at the PicoZed 7030 Schematic, you will see that there is a MUX between Zynq MIO[0, 9, 10, 11, 12, 13, 14, 15] pins and the carrier card JX connectors.  By default, these MIOs are used in SDIO controller mode so that the eMMC storage device on the SOM can be reached as an SDHC device. 

    If you wish to use these MIO pins as GPIOs out to the JX connectors, you will need to first set PS MIO0 such that the appropriate MUX channel is selected to route the MIO signals to the JX connector rather than the eMMC device.  You will also need to disable the SDIO controller that is connected to the eMMC in your hardware platform settings such that the pins can be used in MIO GPIO mode.

    My suggestion is to focus on getting MIO0 to toggle first so that you can set the MUX appropriately.  Once you have reached that point, the remaining path to success should be more clear.

    Best Regards,

    -Kevin

  • 0 in reply to zedhed

    I am relatively new to using these boards so can you please guide me as how to disable the sdio controller in the hardware platform settings? Also how do i choose the needed MUX channel?

  • 0

    Hello there,

    Have you gone through the user guide?

    The most current is located here:

    http://zedboard.org/support/documentation/4736

    Second, to change the various hardware of the Zynq at this level, I would suggest you take the time to go through our Speedways.  Using this material, you will become familiar with the basics of Zynq's Hardware and Software Platforms as well as how to manipulate the platform configuration as you are asking.

    You can locate those on our training resources page:

    http://zedboard.org/support/trainings-and-videos

     

    Start with the Software Speedway.  Once you complete that, the hardware speedway will contain the answer to your question.

    --Dan

  • 0 in reply to zedhed

    I was researching on the thing you told me about choosing between eMMC and the MIO's and found that the jumper JT6 is used to choose between the two, but i cant find jt6 on the fmc carrier card, can you guide me as to where it is available?