Re: [beagleboard] Logic level for PWM, kernel 4.1?

2016-09-20 Thread Graham
If you don't care about the initial state and when Linux is booting, why don't you just invert the duty cycle in software? That would effectively invert the pin polarity. --- Graham == On Tuesday, September 20, 2016 at 10:07:21 AM UTC-5, Gerald wrote: > > Do a PDF search for the pin number. >

Re: [beagleboard] Logic level for PWM, kernel 4.1?

2016-09-20 Thread Gerald Coley
Do a PDF search for the pin number. Gerald On Tue, Sep 20, 2016 at 10:02 AM, Nguyễn Hồng Quân wrote: > > > On Tue, Sep 20, 2016 at 9:50 PM, Gerald Coley > wrote: > >> >> Read the datasheet. It will tell you the state of the pin after reset, >>

Re: [beagleboard] Logic level for PWM, kernel 4.1?

2016-09-20 Thread Nguyễn Hồng Quân
On Tue, Sep 20, 2016 at 9:50 PM, Gerald Coley wrote: > > Read the datasheet. It will tell you the state of the pin after reset, > before the SW has run.. > I don't really care the status in short moment. The reason behind my question is: " ​I want the pin to be 0V when

Re: [beagleboard] Logic level for PWM, kernel 4.1?

2016-09-20 Thread Gerald Coley
Read the datasheet. It will tell you the state of the pin after reset, before the SW has run. Gerald On Tue, Sep 20, 2016 at 9:29 AM, evilwulfie wrote: > > > > you will need an external inverting buffer > > > > On 9/20/2016 7:06 AM, Nguyễn Hồng Quân wrote: > > What I want

Re: [beagleboard] Logic level for PWM, kernel 4.1?

2016-09-20 Thread Nguyễn Hồng Quân
Hi Robert, So there is no way to config the pin? I want the pin to be 0V when PWM is working, because I want to reduce the power drain from my BeagleBone board to feed the PWM pin. It is similar to why we have GPIO at 0V to turn on the LED. On Tue, Sep 20, 2016 at 9:20 PM, Robert Nelson

Re: [beagleboard] Logic level for PWM, kernel 4.1?

2016-09-20 Thread evilwulfie
you will need an external inverting buffer On 9/20/2016 7:06 AM, Nguyễn Hồng Quân wrote: > What I want is, after "reset", the servo motor is supposed to be off, > the pin is 3.3V, and when PWM starts, the servo is supposed to be > started, the pin is 0V. > > On Tue, Sep 20, 2016 at 8:40 PM,

Re: [beagleboard] Logic level for PWM, kernel 4.1?

2016-09-20 Thread Robert Nelson
On Tue, Sep 20, 2016 at 9:06 AM, Nguyễn Hồng Quân wrote: > What I want is, after "reset", the servo motor is supposed to be off, the > pin is 3.3V, and when PWM starts, the servo is supposed to be started, > the pin is 0V. > > Stick an inverter in there. Regards, --

Re: [beagleboard] Logic level for PWM, kernel 4.1?

2016-09-20 Thread Nguyễn Hồng Quân
What I want is, after "reset", the servo motor is supposed to be off, the pin is 3.3V, and when PWM starts, the servo is supposed to be started, the pin is 0V. On Tue, Sep 20, 2016 at 8:40 PM, evilwulfie wrote: you are not making sense. > > pwm pin low - 0v high = 3.3 v >

Re: [beagleboard] Logic level for PWM, kernel 4.1?

2016-09-20 Thread evilwulfie
you are not making sense. pwm pin low - 0v high = 3.3 v On 9/20/2016 1:48 AM, Hồng Quân Nguyễn wrote: > Hi, > > Is there any way to configure logic level for PWM on BeagleBone > Black/Green? I want that in duty cycle, the level of pinout is 0V, > instead of 3.3V. > > I'm using Debian 8 with