Are my DRV8825's backwards?

I purchased a Rumba board and DRV8825 stepper controllers.
I inserted the 8825's just as I would A4988's. I plugged in the USB connector and proceeded to adjust the voltage on the 8825's. I am unable to adjust the voltage properly.
I tried several of the controllers and none of them would adjust properly.
I removed the controllers then plugged in one at a time, thinking that perhaps all 6 at once was too much for USB power. Same result they would only vary by about 0.1vdc.

So I tried some A4988's and the worked properly. I plugged in 4 and they all worked properly.

So I unplugged everything and sat puzzled for a while.
Then it occurred to me to check the pin-outs.
As it turns out the DRV8825's appear to be 180° out compared to the A4988's.

Has this ever happened to any one else?

[www.ebay.com]


A4988's Top Silkscreen_____DRV 8825 Bottom Silkscreen (upside-down)

1 EN------------ VMOT_______DIR--------GND
2 MS1-----------GND________STP--------FLT
3 MS2-----------2A__________SLP--------1A
4 MS3-----------1A__________RST--------2A
5 RST-----------2B__________M2---------1B
6 SLP----------- 1B__________M1---------2B
7 STEP---------VDO ________M0--------- GND
8 DIR------------GND________VMOT---- EN
Adjustment End Adjustment End

Edited 2 time(s). Last edit at 12/08/2016 11:27AM by kd6hq.

Yes, welcome to the club
The potmeter used for orientation trapped me too...

I went back an read the E-bay add again, "and interface that are nearly identical to those of our A4988 stepper motor driver board"


I did not catch this the first time around.

Were you able to get them to work with properly orientation?
I have not been able to, I guess I burnt a part or something, not sure what.

Thanks for responding.

Edited 1 time(s). Last edit at 12/08/2016 02:36PM by kd6hq.

Well I finally got around to trying the 8825's again. I can now adjust the voltage ok, but they are running hot for just a few minutes of operation.
It could be that I have damaged them, as I put the A4988 drivers back in and they are running normal.

Is anyone else using the DRV8825's in the Rumba board? I'm not even sure they will work with Rumba but I don't see why they would not - but then again I don't know for sure.

thanks

I had set this aside for a while and am just now getting back to it.
I have been building and waiting on parts to arrive.
I now have the basic printer assembled and have gotten the X & Y axis to more.
The DRV8825's seem to be working now. But as you can see my the pictures (above) they need to be rotated 180 degrees from the A4988.

I still need to lengthen the stepper leads, get the hot end working and the filament spool(s) mounted then I can give it a proper test, but so far so good.

Hi,

I think many people have had this issue, including me.

They do get damaged when you put them in backwards so i hope yours are fine.

I just got my megatronics v3 back to work, i had a broken fuse in the board, i bridged the original one and placed a car 10A fuse between psu and board.
If it ever blows, i just plug in a new one in the adaptor.



Edited 1 time(s). Last edit at 01/22/2017 08:38PM by Govahnator.

I think so also, that's why I included the diagrams.

Well I lost 2 before I figured out what happened.
I had extra's so it was ok I guess.