PWMPal, Reversible R/C ESC's, and the Basic Stamp 2

Audiorigami

I've got a BS2 and a Novak Super Rooster reversible ESC from an R/C car. The ESC acts as an h-bridge, accepting PWM and controlling a DC motor.

A PULSOUT loop on the BS2 will allow me to create PWM of the type that the ESC wants, but at much too low a frequency. Because the PAUSE command has a 1 ms minimum, my frequency is limited to 60Hz when I'd rather be operating in the 1kHz range. As a result, I get spotty response from the ESC.

My question is this: will the PWMPal help? Can it allow me to control the duty cycle at 1khz or more? Can I control three such ESC's and still do other processing if I get the PWMPal?

Thanks in advance!

Jon Williams

The PWMPAL should work fine for you -- just consider the frequency versus duty-cycle resolution.· The high- and low-time resolution is 25 microsecods.· A 1 kHz period is 1 millisecond, so your output control will be limited to 2.5% (100% / (0.001 / 0.000025)).· If you can live with 2.5% resolution on your PWM signal, then you're good to go.

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Jon Williams
Applications Engineer, Parallax

Audiorigami

Thanks a lot, it worked. I have a PWMPAL working as a controller for two Novak Super Roosters, if anyone has any questions about them.

Next question: My ESCs, the Super Roosters, can only handle 12v. I'd like to use the Motor Mind C instead--will I still need the PWMPAL to obtain a good range of frequencies/duty cycles, or will the Motor Mind C and BS2 work fine together without the PWMPAL?