40X2, 2 different PWM - at same time?

[Tobias Simonsen]

Hi,

Does anybody knows if it is possible to have two different PWM signals out of the 40X2, at the same time?

I would like to make an upgrade on my lawn mower robot, and for that I would like to control the drive motors independent of each other. Eg. run the left motor on 45% PWM and the right motor on 77%, at same time.
Is that possible, and how could the code look like?

Br. Tobias

 

[BeanieBots]

Yes, you can but there are certain caveats some of which depend on which firmware you have.
I can't recall the latest but I'm sure someone will be along soon with a complete answer.
Meanwhile, have a good read about the command in manual 2.

 

[Tobias Simonsen]

Yes, I can see that on page 86 in manual 2, it is described how the HPWM is working. As I can read, I must use it in the single mode and set the setting to %1111. But what shall the polarity be? HHHH? Am I on right track, or have I misunderstood something?

 

[hippy]

@Tobias : The HPWM command is mainly for control of a single motor. What you want is to use are PWMOUT commands, one for each motor.

 

[Tobias Simonsen]

Yes Hippy, that's exactly what I want. Can I do that somehow? With a 40X2 chip, or a 20X2 chip (I got plenty of those).

 

[hippy]

The 20X2 has only a single PWMOUT channel so that will not be suitable, but a 28X2 or 40X2 has multiple PWMOUT channels.

 

[Tobias Simonsen]

Hippy: With independent PWMOUT channels (on the 40X2 chip, of course)?

 

[hippy]

Hippy: With independent PWMOUT channels (on the 40X2 chip, of course)?

Yes, separate channels, each with its own I/O pin, each with independent duty rate control.

 

[Tobias Simonsen]

Uuuuuh perfect! Thanks a million for your quick and fine help, Hippy.