I have a problem with my DRV8825 running a nanotec 6018L3008 stepper motor when I level up the voltage.
Raspberry Pi → frequency generator → DRV8825 → nanotec 6018L3008
The testing power supply had 11VDC and way enough current. The motor runs good.
Now I used a new power supply with a variable voltage adjustment. When leveling up the voltage the motor starts stumbling.
The graph of the oscilloscope shows the trigger signal (yellow) and one outcome for a single coil at 10V, 11V and 20V.
What do I do wrong.
Thx for answering.
It looks like you are observing the switching caused by the current limiting feature of the driver. Did you set the current limit for your stepper motor? You can find more information about how to do that in our video in this post on our blog.
If you already set the current limit, what did you set it to?
thanks for your advise and that helpful link. I adjusted the current level as it is said. Sadly, there is no change in function. (1V at V_Ref)
Now I disconnected the motor from the controller and the results on the oscilloscope are very good. So, there has to be something wrong between the motor and the controller, I guess.
What can that be?
20V - with Motor Nanotec 6018L3008
20V - no Motor
I do not see anything wrong with those plots. The rapid switching on and off shown on the plot with the motor attached is exactly what we would expect for a current limiting driver controlling the motor current with PWM switching.
Setting the current limit to 2A (by setting vref to 1V) on this driver will probably result in the driver overheating and shutting itself off. We do not recommend setting the current limit above 1.5A without sufficient external cooling.
What benefit are you trying to achieve by using a 20V supply? It sounds like 11V was working well.