eQEP1 setup problems with latest debian iOT

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1

Following on from my earlier messages related to this, I am using cape-universal now to setup and control the pins for my mechatronics project. Pinmap constraints mean I need to use eQEP1 and eQEP2. eQEP2 on P8_11, P8_12 and P8_16 is working, but I can’t get config-pin to setup eQEP1 on P8_31, P8_33 and P8_35.

root@beaglebone:/dev# config-pin -l P8_31
default gpio gpio_pu gpio_pd uart qep

You can see qep is a supported mode.

root@beaglebone:/dev# config-pin P8_31 qep
bash: line 0: echo: write error: No such device
Cannot write pinmux file: /sys/devices/platform/ocp/ocp:P8_31_pinmux/state

And that is the error I get…

Does anyone know what is going on here? This 2nd encoder input is the last bit of the pinmux’ing puzzle I need to sort out, all the other GPIO is working nicely now.

Thanks, Hugh

2

Anyone?

3

Found it - cape-universal doesn’t support eqep1, this was added to cape-universalh 4 months ago but the code wasn’t merged into cape-universal. I will look at doing this now.

4

I actually ran into this too recently and have modified cape-universala-00A0.dts to enable pins P8_33 and P8_35 for eqep1:
https://github.com/beagleboard/bb.org-overlays/pull/46

Thanks
Drew

5

I just pushed another sync up: P8_31 was mising ecap. :wink:

https://github.com/beagleboard/bb.org-overlays/commit/6197c268c1b875a2c066635413c9742b720762bc

I'm going to do a quick space -> tab conversion on cape-universal*.dts
as i need to also sync all the eqep options with 12 or so
univ-<board>-<enable>.dts

Regards,

6

Thanks guys, I’ll keep an eye on the repository and grab a copy once things are finalised.

7

Okay all pushed out..

run:

sudo apt update ; sudo apt upgrade

and it should show an upgrade for bb-cape-overlays
bb-cape-overlays_4.4.20170510.0

reboot and it should work, let us know..

Regards,

8

It looks like we are good-to-go. Thanks for sorting this out guys :slight_smile:

Hugh

9

Just to add to this again - this fix is still required if you use the 8.7 IoT image but is not required if you use the 9.1 image. Also note that the pru_ecap mode for P9_42 is now called PWM when you call config-pin

10

OK, looks like pru_ecap mode was removed from the .dtbo as an option for this pin - PWM is not what you want if you want to use the pru1 ecap device as a PWM generator - you need mode 3, which is no longer a valid option. Time to downgrade again to 8.6 :frowning: Why can’t these options stay when the universal overlays get updated?