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stepper v1.2 + RAMPS

Posted by LiavK 
stepper v1.2 + RAMPS
February 02, 2011 09:13PM
Hi. I'm curious if RAMPS can drive my old skool stepper boards. Right now I'm using the Tonokip firmware + repstrapper. I've tried with the stepper boards and RAMPS set to both full and half stepping -- neither seems to work. The motors will turn a step, then seize.

Is there something else I need to do to get this working, or does it just not work?

L
Re: stepper v1.2 + RAMPS
February 02, 2011 10:21PM
Are you sure the step and direction pins are not crossed up? You might also try inverting the enable pin in the firmware. Looks like the v1.2 stepper driver enable pin works differently from the normal polulu boards. You have to set the enable pin "high" or "on" in order to enable the stepper motor outputs. With the polulu drivers, it has to be "low" to enable the outputs.

Any stepper driver that is capable of accepting 0 to 5V signals and has enable, step, and direction inputs should work.
Re: stepper v1.2 + RAMPS
February 03, 2011 08:02PM
Hi dazed.dnc.

I know there is an issue with the inverted enable pin, but I've tested the v1.2 boards *many many many* times successfully with the setup described at: [reprap.org].

Just a dir + step single, and a connection to ground.

Direction and step pins were correct, as far as I could tell (I did try swapping them, just to be sure, and got nothing.)

L
Re: stepper v1.2 + RAMPS
February 03, 2011 08:51PM
Your board has two LEDs near the motor output that should flash as the output switches. If one or the other or both don't flash, it may indicate a damaged stepper driver chip.

Maybe the motor is wired wrong? IE: maybe one coil has reversed polarity? I think that would cause more of a vibration between two magnetic poles rather than just taking one step, but it might be worth a check.

Another guess would be that maybe one of the step/direction output pins got fried. Pull them off the stepper driver and hook up a volt meter or LED while you try to drive a motor. Make sure they can't short circuit with anything! This should show you if the output is working or not.
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