[najnielkp]

i am using a microcontroller Shopbot tools, to send step and direction to the gecko g 340.i have good speed and control but in one direction only. the step pin measures 3.3 volt with the multimeter. the direction pin measures 5.5v one direction and when attempting to reverse , the measurement
is 3.3v.is the voltage too high to create reversing, if so what remedy ,pull up, pull down resistor ?

[Evodyne]

Doesn't sound like your direction line is putting out a solid "low" signal. Here is a link that might help: TTL/CMOS Levels.

A real quick thing to try would be to disconnect the direction line and tie the input on the Gecko directly to ground. It should then reverse, verifying your theory.

Good luck. (wedge)

[najnielkp]

evodyne , thank you for the reply. yes , the direction reverses when the direction lead is disconnected.

[Evodyne]

I guess I'd be inclined to try a pulldown resistor from the direction input to ground-something on the order of 5K (for 1mA) as an initial try. Use your VOM to see what you have with it in place and adjust as necessary. I probably wouldn't go much below 1K (5mA) without checking to see what the output is rated for-don't want to let any smoke out, right? Good luck!

[najnielkp]

problem solved, works great. had 1k resistor from the controller to the gecko. thank you for the help.

[Evodyne]

Glad to hear you are up and running. Seems to me that you were on the right track from the beginning-good troubleshooting skills! Happy motoring.