[Dr Honda]

Hi All,

OK… I think I know the answer to this… but I want to make sure.

I am working on automating a saw for my shop, and I want to use a Gecko with a servo to feed the stock. If I’m using a PIC or a stamp to run the Gecko… All I need to do is hold the “Direction pin” either high or low while pulsing (bit high to low) the “Step pin” to drive the servo…Right?

Then… does anyone know if the logic level (bit high or low) from a Stamp or a PIC, IO is good enough to drive a Gecko?

Thanks

[Dr Honda]

Hello.

I guess it wasn't a simple question.

[Richards]

It's more involved that you might think. I can't find the current rating for the Step and the Direction signals for the G320 servo driver, but the G201 and the G202 stepper drivers require at least 15mA of current per signal. (The G203 is the exception, requiring much less current.) Also, I'm not familiar with the PIC or Stamp microprocessors, but the microprocessors that I use can NOT drive an output requiring 15mA. They must be used with an extermal driver chip (buffer). Also, unless you're going to be running the motor at very low speeds, you'll need to program both an acceleration ramp and a deceleration ramp. The actual step pulse for a G320 servo driver starts high, goes low for at least 0.5 microseconds, and then goes high again. The direction signal is as you described it, High for one direction and Low for the other direction. The G320 manual does not have information about when you can change the direction signals, so be careful; however, the G202 manual has some information on the last page that may also apply to the G320.