Request for GPIO Examples

[punit vara]

On Wed, Mar 23, 2016 at 7:51 PM, Worth Burruss <worth at motioncontrol.org> wrote:
> On 23 Mar 2016 at 0:57, punit vara wrote:
>
>> Hi Worth Burruss,
>>
>> This year I proposed a plan (https://goo.gl/cGCXbS) to develop Beagle
>> bone black BSP which includes PWM drivers as well as I2C driver. Could
>> you please suggest me testing methods to test PWM on BBB ?
>>
>> Regards,
>> Punit
>>
>
> Punit,
>
> I will preface this with my solutions tend to be overly complex and I do not know specifically
> what is available to use to test with in the BBB.  So this may not be what you are looking for.
> It also depends on the frequency of your PWM signals.
>
> When I think of test on hardware, I want to know it is working the way I think it is working
> (proving correctness).  For PWM, this means the duty cycle is correct.  I would be using
> another hardware counter timer to measure the High time followed by the Low time and doing
> the math to prove that the times are correct for the programmed duty cycle.
>
> As an alternate, with appropriate selection of PWM frequency and software timers, you can
> do the High and low counting using the timers.
>
> As for me, I would find it hard to see the change in an LED's intensity except in a crude
> fashion, so would not meet my personal goal of proving correctness.   But you may be
> thinking of ON and OFF times in seconds, In which case an LED and maybe a stop watch
> would be appropriate.
>
> Hopefully this gives you some ideas.
>
> Thank you,
>
> Worth Burruss
>
>
>
>
Did you mean to say ?  General purpose timer that is continuous
increasing can be configured to toggle the PWM output high when a
certain value reached and low when it overflows. I have referred this
from here (

Activating PWM via Timer Registers)

http://elinux.org/BeagleBoardPWM#OMAP_Mux_Configuration