Interconnecting Enable pin on DRV8825s

Hey everyone,

I am having some issues with my DRV8825 stepper drivers. I am using two of them, for two NEMA17 motors. I have hooked them both up and one of them is working fine, while the other is not. The wiring is identical, and all measurements I have made seem to indicate that it is fine.

I think the problem lies in the enable pin. This is why: The wiring seems to be okay on both DRV8825s, but even when one of them is enabled, I would expect the power to go to the other one as well, since I interconnected the enable pins so it would only use one output on the Arduino (Uno by the way). I did this because in the design I want both stepper drivers to be enabled or disabled at the same time, and figured I could do this with only one pin. The power DOES get to the first stepper, but then somehow not to the second one, even though the board itself IS powered.

The other option I am thinking of is that I somehow fried my driver?

So my question: Is what I want possible or do I have to hook the other one up to an extra pin on the Arduino? Or is something else wrong?

Thanks guys!

As you have not provided a wiring diagram I can't tell what you might be trying.

It is certainly easy to fry a stepper driver if you allow a wire from the motor to the driver to be disconnected even briefly while the driver is powered.

...R
Stepper Motor Basics
Simple Stepper Code

The bar _ over the enable pin means it it active low. Does your program set it low or high to enable the chip?

Paul

I have driven 4 DRV8825 enable pins from one Arduino output, so driving multiple enable pins is not a problem.

Test each driver board with the same test sketch to see if it works.
If they both work separately then swap them and see if the problem moves with the driver
or is with one of the Arduino pins.

Post your code too...

Hey guys I just did some more measurements, and realized I left out one crucial measurement. I forgot to measure the value of the fault-pin to determine whether or not something was wrong. The value reports back LOW, which basically means my board has shut down to overcurrent and/or thermal protection. Since it does not get hot at all, I am assuming it must be the overcurrent protection. Does this mean it is fried? Because there is literally nothing happening for the motor, so an overcurrent problem does not seem likely, am I right?

Also, I would be completely fine making a Fritzing schematic, but for now I am trying to figure it out without one, because I figured I didn't need it since I wired the two identically, and one of them is working.

If I absolutely need to though I will definitely post one for you guys (since I do not have one before I started soldering :slight_smile: )

Thanks guys!

Visually inspect carefully for any shorts on the board that might have triggered the problem?