Stepper motor driver overheating, always driving motor, how do I stop it?

Hi,

I was writing a simple code for the arduino to test out my setup and i noticed that the stepper board were getting immediately hot, very hot.

By accident I figured out that they are always driving the motors by trying to turn of the driving rods while power was on, but no signal was given to turn.

I am sending a low signal to all step and dir wires, the GNDs are connected to the arduino GND and the enable wires are not connected to the arduino

Is this the expected behavior from the driver board?
Can I stop this from happening?
What does the enable pin do?

Thanks!
-Leav

RTFM!!!
[reprap.org]

-Leav

I did the same thing about 10 times when I first started firing up my Darwin - ask a question on the forum, only to find the answer 4 minutes later.



Wade

Leav: I dont think this problem is only RTFM.

I suspect that there is some noise problems involving.
Namely, if I attache the step, dir, gnd cable without connecting anywhere(it is only connected on the stepper board and not at arduino).

It turns like a crazy. If I remove this cables, it stops turning.

So I think there are some noisy problem.

Even if the enable pin is high by default, it should not turn without step and dir command. I think.

khiraly1, I think Leav was talking about the "enable" pin, which isn't used with the Arduino electronics currently. The steppers are always on, but not moving, just holding position - one of the advantages of steppers, depending on how you use it. It also means you have to set your currents carefully, as they're going to be on all the time. I haven't turned mine off in over a week now.

You're right about the noise thing - the stepper shouldn't turn unless the driver gets a pulse on the "step" pin.

Sounds like you might have a grounding problem; poke around with a scope, or even a multimeter set to V AC; look for AC voltages on your grounds. Check the Reprap power supply ground voltage, AC and DC, relative to the Arduino ground voltage. Mine had 48V AC at one point due to an ungrounded laptop power supply, and my Arduino being grounded to the laptop, but the stepper boards grounded to the Reprap power supply.

Properly grounding my laptop chassis helped tons. Also, make sure you've got a proper 3 wire ground on your Reprap power supply; I was using a 2 wire cord for a while, and it was making my temperature measurements a tad noisy, which resulted in higher than normal heater temperatures, due to a quirk in the firmware.

Wade

Edited 1 time(s). Last edit at 11/10/2008 12:51PM by Wade.