PocketBeagle cannot access ADC with RT Kernel 4.9

Embedded Linux Discussions
1

Hello,
Just received my PocketBeagle and I looking to implement a Flight Controler based on the BBBMicro.
Flashed the latest Debian IOT and I can read the ADC when disabling
disable_uboot_overlay_emmc=1
disable_uboot_overlay_video=1
disable_uboot_overlay_audio=1
disable_uboot_overlay_wireless=1

cat sys/bus/iio/devices/iio:device0$ cat in_voltage0_raw read values OK

Upgrade to RT sudo /opt/scripts/tools/update_kernel.sh --bone-rt-kernel --lts-4_9

reboot
there is no file sys/bus/iio/devices/iio:device0$ cat in_voltage0_raw

Thanks

2

Hi @patrickpoirier51,

I haven’t finished back-porting PocketBeagle support to all the old kernel versions.

Use the “v4.14.x-bone-rt” instead of “v4.9.x-bone-rt”…

sudo /opt/scripts/tools/update_kernel.sh --bone-rt-kernel --lts-4_14

Edit: these are ignored by the PocketBeagle…

disable_uboot_overlay_emmc=1
disable_uboot_overlay_video=1
disable_uboot_overlay_audio=1
disable_uboot_overlay_wireless=1

Regards,

3

OK thanks

WHAT about PRU ?
Do we have to set anything special to get them working on the Pocket under 4.14 RT ?

4

All the bone releases, have the pru enabled by default thru uio. (aka compatible with 3.8.x’s)

But let us know if you have any issues, i haven’t personally had time to test the uio_pruss interface yet in v4.14.x kernel’s…

Regards,

Edit: patches in v4.14.x:

5

OK I will report back

Thanks Robert, for your excellent service.

6

Hello,

ADC is working OK with 4.14 RT
PRU I am still struggling… Question:
You say that pru are enabled by default thru uio, it seem contradictory with my uEnv.txt:
###PRUSS OPTIONS
###pru_rproc (4.4.x-ti kernel)
uboot_overlay_pru=/lib/firmware/AM335X-PRU-RPROC-4-4-TI-00A0.dtbo
###pru_uio (4.4.x-ti & mainline/bone kernel)
#uboot_overlay_pru=/lib/firmware/AM335X-PRU-UIO-00A0.dtbo

and shouldn’t the compatible field within dtbo include the pocket ?

Best Regards

7

Comment out, the 4.4 option, that’s for ti’s v4.4.x-ti kernel

uboot_overlay_pru=/lib/firmware/AM335X-PRU-RPROC-4-4-TI-00A0.dtbo

and give this a go:

uboot_overlay_pru=/lib/firmware/AM335X-PRU-UIO-00A0.dtbo

Regards,

8

Yes, thats what I did and so far so good, hopefully a little Pocket will be flying soon :wink: