PWM

[markus-aurelius]

Hi,

First of all: Nice Work!

Question: Is there anything to consider/prepare when using the PWM?. Demo_PWM does compile and starts but there is no signal (anymore). Only a single time there was output but after rebooting (pwr off/on) the BBB I don't get it running anymore. Using Python with Adfruit_BBIO PWM it works.

Thanks for any advice!

[ML-Cai]

Hi markus,

I think the pin mux mode of your PWM pins not configured to ehrPWM mode ,

using ./EP_status toolkit to list the pin information you want to use ,
compared MUXMODE filed with BBB_SRM table.11 and table.12 (Expansion Header
P8/P9 Pinout).

BBBio can't change the pin mux mode , because the configure register
,CONTROL_MODULE register , only accessible in privilege mode.

I try to configure pin mux mode using device tree overlays , reference from
this website .

https://learn.adafruit.com/introduction-to-the-beaglebone-black-device-tree/overview

the ehrPWM overlay is BBBIO-EHRPWM-00A0.dtbo in BBBIOlib/overlay directory
, please try these :

cp BBBIOlib/overlay/BBBIO-EHRPWM-00A0.dtbo /lib/firmware/
echo BBBIO-EHRPWM >> /sys/devices/bone_capemgr.*/slots

using ./EP_status toolkit check again , the pin mode of P9.22, P9.21 will
be mode 3 .

and the ehrPWM pins can configured in different expansion header pinout ,
you can modify the BBBIO-EHRPWM-00A0.dts and recompile it using build
script .

hope these information works, i'm sorry i dont specify these question
clearly in github .

Thank you for your advice !

2014-05-01 3:51 GMT+08:00 markus-aurelius notifications@github.com:

Hi,

First of all: Nice Work!

Question: Is there anything to consider/prepare when using the PWM?.
Demo_PWM does compile and starts but there is no signal (anymore). Only a
single time there was output but after rebooting (pwr off/on) the BBB I
don't get it running anymore. Using Python with Adfruit_BBIO PWM it works.

Thanks for any advice!

—
Reply to this email directly or view it on GitHubhttps://github.com//issues/2
.

[Gnrody]

Hi VegetableAvenger,

thank you for a clear BBBLib !!
I would like to ask if you have an updated lib?

I am new to the BBB, and I have compiled and run successfully the GPIO,
The PWM demo has a an issue since it stop the time base clock so it always exit with the clock faillure.

Also the new systems (debian 9 ) the slots file is removed, the universal cap is enabled automaticaly in the uboot! but since this library in based on the MemMap this is not a big issues!!

Thank for your advice!!

Rodrigue.

[hugoboss00]

Hi VegetableAvenger,
do you have any update on the PWM "clock failure" problem?