high resolution EhrPWM with Ubuntu Linux on BeagleBone

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Sameer

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Nov 16, 2012, 11:46:29 AM11/16/12

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Hi everyone -- another beagle question, hopefully someone here can help?

I am trying to get high resolution PWM out of my beagle bone running ubuntu 12.10 to control servos and other hobby RC gear. I have successfully been able to use the /sys/class/pwm/ehrpwm to create PWM output, however I am having trouble with the resolution.

The RC standard is to run at 50Hz with each PWM signal lasting from 1000-2000us. I have set the frequency to 50, however it appears that the duty_cycle must be passed as an integer percentage. Therefore in order to get 1ms I set the duty cycle to 5 and to get 2ms I set the duty cycle to 10. This gives me only 200us resolution, while I would prefer resolution closer to 1us,

Anyone know if that is that possible using the standard pwm support?

Thanks,

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