2 drivers DRV8825 can not work at the same time

Support Motor controllers/drivers and motors
1

Hi,
This is my schematic:

933×646 26.6 KB

I use msp430g2553 to control these two drivers.
But when I connect 2 drivers, noise happens and only one of steppers (not causing noise) works. The other does not work.
It’s weird that when I remove one of any of them (the one causes noise or the normal one). The other works.
I really don’t know why? I realize that when I connect more DIR STEP pin it will cause noise.
Please help me.

Video:
youtu.be/2UYPJq2iHSA
youtu.be/noQiXciUlck

p/s: I have another system with 2 big easy drivers and having the same schematic and they both work perfectly. But I really want to use TI drivers for this project. Please give me some solutions.

2

What are is the voltage and the current capability of the power supply?
What stepper motors are you using (what are their voltage and current ratings)?

3

not really find a way… :frowning:

4

Hello.

The potentiometer on the stepper motor driver is used to set the active current limit. Just spinning the potentiometer on the drivers is not an appropriate way to set the current limit, and I suspect they are not set correctly for your stepper motors. You should follow the steps described under the “Current limiting” section on the DRV8825 stepper motor driver’s product page to set the current limit on your drivers.

- Jeremy

5

Only one of my steppers work perfectly but it gets hot.
The other also works but weaker and does not get hot.

Sometime the cool one stop working.
Any solution to fix this.

6

[quote]Any solution to fix this.[/quote]Set the current limit correctly, as Jeremy suggested.

7

Can anyone make a video tutorial how to set current limit?
I measure VRef is always larger than 1V. :(.

8

How are you measuring the VREF pin? Could you post pictures of your setup and how you are measuring the VREF pin?

A video tutorial for setting the current limit is something we are interested in making; however, it is not currently in the works.

- Jeremy

9

[quote=“JeremyT”]How are you measuring the VREF pin? Could you post pictures of your setup and how you are measuring the VREF pin?

A video tutorial for setting the current limit is something we are interested in making; however, it is not currently in the works.

  • Jeremy[/quote]
    Sorry for slow reply.
    That’s how I measure VREF. (In Full Step Mode).

    The schematic is at first post.
    When the VMOT is off VREF is always > 1V.
    VMOT on VREF ~~ 10V.
    VMOT = 12V.

Steppers: Minea 17PM-K303V - Rated Voltage: 3.2V. Rated Current 1.2 A. (as in datasheet).

My drivers still does not work.

10

If Vref = 10V, there is a major problem, and your board is bust.

Try this instead: Don’t bother measuring at that Via that you pointed to in the picture. Just put your positive (red) probe onto the metal potentiometer (screw terminal thing.) Measure from there.

I am hoping maybe you didn’t measure the via correctly. But if you get 10V again, then you have a blown board for sure. I don’t think Vref is 10V tolerant, and the most it ever should get is 3.3V