I have the same problem, I tried with a Stepper Motor with 28cm Lead Screw: Bipolar, 200 Steps/Rev, 42×38mm, 2.8V, 1.7 A/Phase (pololu.com/product/2268) at 12V and Vref=.62V for the drv8825.
So the limit current setting seems to be ok, almost 0.5A below the motor’s rated current but the drv8825 only gets hot and doesn’t make the motor move at all, any help?
Since it sounds like you have your current limit set to an appropriate value, it does not seem like you have the same problem, so I have moved your post to its own thread.
It is normal for the DRV8825 to heat up, since the stepper motor is drawing current even when it is stationary. Keep in mind that what you and I might consider hot is not necessarily hot for electronics. As pointed out in the warning on the DRV8825 product page, this product can get hot enough to burn you long before the chip overheats. Could you tell me more about your setup? How are you providing a step input to the DRV8825? How fast are you trying to step the motor? Are you using any microstepping? Also, is there any load on the stepper motor?
By the way, it should be fine to increase your current limit to something closer to the 1.68A rating of that stepper motor, as long as it is below the maximum that the DRV8825 can handle, which is 1.5A without any additional cooling.
Thank you Brandon, here are more details:
I am using the minimal connection diagram for full step mode in wich !fault pin is connected to logic voltage and sleep and reset are connected together,
Logic voltage comes from a 7.4V battery that goes into a 7805 regulator.
Motor voltage is 12V which comes from an AC power adapter.
The step pulses are provided by a PIC microcontroller, it is just a simple functional test so the PIC only gives a step every second, with the same direction all the time (dir pin to 5V).
No microstepping, or other fancy options, still the motor does not move it only makes a high pitch soud and noise when trying to move.
Now it works, seems that the delay I was using for the step high was quite not precise, used the timer to make a more precise pulse train and now it works.
Thank you very much
I am a new user here, and would you mind if I ask you some question about your posted.I am about to do what you are already did…
You posted here that you use the motor 2.8 v. voltage rating and drv8825.
You put 12v. to the VMOT of drv8825. and adjust the current limit.\
My question is…
Can we put 12v. to drive the 2.8v. motor ?
Because I am now about to drive 4v. motor with A4988 driver.
I am glad you were able to figure out what the problem was and get it working. Thank you for letting us know.
Pucomponent, a short answer to your question is that you can drive a stepper motor from higher than its rated voltage if you are using a driver capable of active current limiting (to keep the current below the rated current of the stepper motor so it does not overheat). However, I noticed that you posted a very similar question on another thread on our forum. It would probably be easier for everyone to follow if you continued your conversation with Derrill in the thread where you originally asked this question.
Thank you for your answer…
Now I am very clear with the driver …