Arduino Forum

Using Arduino => Motors, Mechanics, Power and CNC => Topic started by: markmarkmark on Apr 11, 2015, 08:27 pm

Title: DRV8825 stepper motor driver problems
Post by: markmarkmark on Apr 11, 2015, 08:27 pm
Hi there, I am using DRV8825 stepper drivers (3 of) to control 2A motors.

They are wired up as so...

http://mchobby.be/wiki/index.php?title=DRV8825

(it shows how the wiring is done about half way down the page)

with the Enable pin attached to a pin but LOW when in use.

I pulled the enable pin of two of the drivers and now they seem to not work even when the enable pin is connected again? (and it was set to LOW anyway)

I know the code is okay because it was working previously, it is just a slightly adapted version of that shown on the webpage.

Does anyone have any advice on how to get this working again or have I destroyed the DRV8825 drivers?

Thanks, Mark

Title: Re: DRV8825 stepper motor driver problems
Post by: Robin2 on Apr 11, 2015, 09:02 pm
I don't know what you mean by "pulled the enable pin of two of the drivers" (is it anything like pulling teeth?).

Assuming you kept the voltage between 0 and 5v I can't see how any damage could have happened. I don't think it is normally necessary to have the enable pin connected.

If you disconnect the motor from the driver (or allow it to be disconnected) while the system is powered up that will probably damage the driver.

Try this simple servo code (http://forum.arduino.cc/index.php?topic=277692.0)

What power supply are you using for the motors (volts and amps).

...R
Stepper Motor Basics (http://forum.arduino.cc/index.php?topic=284828.0)
Title: Re: DRV8825 stepper motor driver problems
Post by: markmarkmark on Apr 11, 2015, 09:50 pm
I mean that there was a cable connected between the enable pin and the arduino on pin 13

pin 13 on the arduino was set to LOW and everything was great.

But then I pulled the cable out of this pin whilst the motor was spinning by accident.

Now the motor just hisses but the motor does not move, even though I have plugged this cable back in... It does not work with the cable out or in :(

Is there a possible reset?

cheers, Mark
Title: Re: DRV8825 stepper motor driver problems
Post by: markmarkmark on Apr 11, 2015, 09:51 pm
the supply is 24v 6A
Title: Re: DRV8825 stepper motor driver problems
Post by: MarkT on Apr 12, 2015, 12:00 am
You perhaps let the loose cable hit the 24V supply, that would fry it nicely...

Disconnecting the logic connection to enable shouldn't have any permanent ill-effects.

Disconnecting the _motor_ itself when things are powered up is likely to destroy the
driver.
Title: Re: DRV8825 stepper motor driver problems
Post by: markmarkmark on Apr 12, 2015, 10:55 am
I am sure that didn't happen as I kept hold of it an plugged it straight back in...

is there perhaps a way to reset this driver so I can give that a try?

Thanks everyone, Mark
Title: Re: DRV8825 stepper motor driver problems
Post by: Robin2 on Apr 12, 2015, 10:59 am
Is there a possible reset?
I'm not sure that there is a diagnostic alternative to trying another stepper driver board.

...R
Title: Re: DRV8825 stepper motor driver problems
Post by: markmarkmark on Apr 12, 2015, 11:12 am
I thought this may be the case...

I was just thinking, it could be in sleep mode. I have the reset and sleep joined together with a jumper.

It wasnt previously but it's behaviour seems sleepy
Title: Re: DRV8825 stepper motor driver problems
Post by: Robin2 on Apr 12, 2015, 03:38 pm
It wasnt previously but it's behaviour seems sleepy
Do you mean it was working when the reset and sleep were NOT connected and now it is not working when they ARE connected ?

I don't think "sleepy" is a recognized technical term for computers or motors - only for brains

...R
Planning an Implementing a Program (http://forum.arduino.cc/index.php?topic=261445.0)   Several things at a time (http://forum.arduino.cc/index.php?topic=223286.0)    Serial Input Basics (http://forum.arduino.cc/index.php?topic=288234.0)    Stepper Motor Basics (http://forum.arduino.cc/index.php?topic=284828.0)
Python-Arduino Comms (http://forum.arduino.cc/index.php?topic=225329.msg1810764#msg1810764)   Python GUI demo (http://forum.arduino.cc/index.php?topic=271097.0)    EzScrn (http://forum.arduino.cc/index.php?topic=312547.0)
Title: Re: DRV8825 stepper motor driver problems
Post by: MarkT on Apr 12, 2015, 08:33 pm
It does sound like the DRV8825 got fried, the chip doesn't have persistent state, so power
cycling is all you can do.

Perhaps ground came loose too - then you'd risk static-discharge on reconnection if the step/dir/enable pin(s) made contact before ground.  The 24V supply is floating?