PWMOUT only on two output, that are really inputs?

Am I reading the manual (section 2, page 128) correctly? Can I only use the PWMOUT on 2 specific ports on my 28X1?

This would mean that I can't run more than two outputs with pwm, and that has to be the digital in/outs 1 and 2, so there's no hope of running it through the onboard L293D??

I must have missed something, surely there is a way around this. Pulsout maybe? I'm R'ing T. F'ing M. now, but if somebody already knows the answer, that would be helpful..





Oh, wait, HPWM (page 62) might be what I'm looking for, isn't it...?


You are correct. Thats one of the reasons I build my own board for edward. Also, and that’s a real bummer, you cant use pwm and servo/servopos at the same time.

So even if you have a board where the pwm ports are connected to a motor driver, you’d have to replace either the servo or the pwm commands with repeated pulsout commands.


You can speed-control two motors with 2 PWM pins and to regular out pins.

If you understand how HPWM works, please let me know because it remains a mystery to me.

so if I hook oddbots Simple
so if I hook oddbots Simple motor control to a PWM output, I’ll Have smooth motor operation, But I can forget about running any servos? fuggit! I left my manuals at work and hate reading on screen. This’ll be a loong weekend…


You can have smooth motor operation with oddbots simple motor control, but you’ll have to program the PWM bit yourself. You can use both commands in one program, but they wont run at the same time because they both use the same timed interrupt to run in the background.

Its not all that hard to write your own PWM code to pulse the motor controller pins.

What’s unclear about HPWM?
What’s unclear about HPWM?

But, if I only use the

But, if I only use the PWMOUT upon startup, and then only use PWMDUTY after that, would that allow for use of servos?

If I understood the manual correctly PWMDUTY wont reset the internal clock…

As far as i know you can’t.

As far as i know you can’t. If you have your PWM already running that means it is using the internal timer to coordinate itself. Whenever you call the servo command (since it sends pulses at regular timings, similar to PWM in some way) it screws the timing for PWM, and vice-versa (if you call pwm after servo, the servo timing gets screwed).

I guess you’ll have to use 2 brains…

These guys are all correct.

There is simply no way of running PWM and servos at the same time. I switched to an I2C servo driver for this reason -By the way there is a good servo driver chip available for about 20 bucks… And yes, this is a major downfall of the 28x board.

Now, in terms of the Hpwm stuff… No one anywhere knows how it works -it you get it done, you would be the first.

Time to make your own board

i don’t see what’s so hard
i don’t see what’s so hard about hpwm… the manual says it all!

maybe Sasquash IS HPWM! :slight_smile:
maybe Sasquash IS HPWM! :slight_smile: i’ll give it a go when i have some free time, maybe having an oscilloscope might help in this case (but i don’t have it!)