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JTrotta / RaspberrySharp

A .NET/Mono IO Library for Raspberry Pi This library is a complete refactoring of Raspberry-Sharp libraries, merged into one library and updated to RB3, CM3 and RB3+
MIT License
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Generating PWM Signals #12

Open moelski opened 6 years ago

moelski commented 6 years ago

Hi ! There is one thing missing in this Lib ... generating PWM signals. At the Moment I see 3 different ways ....

1) Using the Hardware like in this lib: http://www.ofitselfso.com/RPICSIO/Help/RPICSIOHelp_PWMPortExample.html

    # enable one PWM with GPIO_18, header Pin12 by default
    dtoverlay=pwm.dtbo
    # enable two PWMs GPIO_18, header Pin12 and GPIO_19, header Pin35 by default
    dtoverlay=pwm-2chan.dtbo

2) Using Software PWM with Pigpiod as a service (can be accessed by TCP). I used that in some cases and it works really well. 3) Writing an own Software PWM class - but at the moment I have no idea how fast we can toggle Pins...

What do you think about generating PWM directly on the Pi ?

Dominik

JTrotta commented 6 years ago

We can try. But I remember on old P1, PWM was very CPU expensive. Now I'm using external chips, but we can try on new pis. I do not have any preference; point 1 should be tested, point 2 do not know you can try , point 3 should be easy, we can toggle at 1ms.

JTrotta commented 6 years ago

Good news, I'm going to implement the original bcm2835 PWM code. I will create a new folder like InterIntegratedCircuit that will contain all PWM driver code. Stay tuned.

moelski commented 6 years ago

Hmm that means we will only have 2 Channels, correct ? I will place my pigpio based code the next days as a PR. Not the best solution, but itś ok for controlling Servos and Motors.

Dominik

JTrotta commented 6 years ago

Yes 2 channels gpio 18 and 19. If we want more, we need external chip like TLC5940 or PCA9633.

wezzix commented 6 years ago

I was just looking for PWM functionality. Did you make it work?

JTrotta commented 6 years ago

@wezzix I did not do any test on PWM.