PWM frequency on BeagleBone

Hardware
1

Is there a method to control the PWM frequency form node-red running on BeagleBone Black? The Raspberry PI nodes have this but the BBB seems to have poor support for features like this. It suck because the BBB has a nice IO assortment but no easy way to use them.

2

It’s just waiting for you to seize the opportunity and write it. Then it won’t suck.

3

Ok. Fair enough. But now you open up a whole new can of worm questions...

Here is what I think I know:
The only available (and current) module to control the IO pins of BBB is "node-red-contrib-gpio". It just uses johnny-five and johnny-five uses beaglebone-io.

Is all that just one one library wrapping around another and that around another just to get the job done?

What I mean is, isn't beaglebone-io the code that is actually doing the work of talking and controlling the physical hardware, and if I want to add, say, PWM frequency then it better be a feature of beaglebone-io in the first place... Right?

So lets say the PWM frequency is not a control that is written into beaglebone-io, then what? Do i have to rewrite my own version of beaglebone-io and then a new version of johnny-five to include it and then finally a new node-red-contrib-gpio to allow those new feature access?

I have know Idea where to start and all above is just a total assumption of what I supposed to do. Also. I don't actually even know how to do any of the above anyways.

4

That's the basic problem with boards that have been made to compete with the Raspberry Pi ones.

There just isn't the same level of support for them, as the Pi, in any programming language

2 Likes
5

Actually reading the docs for node-red-contrib-gpio says it should already support PWM so what have you tried ? Where is it failing ? Failing that there are numerous how to guides for python scripts that could be called from an exec node.

6

node-red-contrib-gpio supports PWM duty cycle only. I need to set the frequency too. Problem is that the the frequency is 2khz hard coded and that makes a lovey noise in my circuit. I need something above the audible range.