June 02, 2020, 03:44:53 pm

bb a4983 current

Started by 0crash0, December 13, 2016, 12:45:00 pm

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0crash0

Hello how i can control current of stepper motor at this driver?
https://www.olimex.com/Products/RobotParts/MotorDrivers/BB-A4983/open-source-hardware

i must change r7 = 100k   to variable resistor?

crallian

March 28, 2017, 11:59:43 pm #1 Last Edit: March 29, 2017, 12:44:09 am by crallian
As I understand, by default, Vref=Vdd/2
Rsense=0
To make Rsense >0, I cut the lines at R4 and R5.

I could then put resistors between the Rsense connectors and ground.
As Vref=2.5v, 0.330 ohm Rsense would give approx 1A.
At this current the driver was warm, but I could touch it.

To make a neater solution I just put 0.330 ohm resistors at R4 and R5.

Modifying R2 and R7 would change vref, but i still think you need Rsense>0.

Edit, see image
https://m.facebook.com/photo.php?fbid=10208430076339480&id=1533426356&set=a.2306553273303.2099245.1533426356&source=56&ref=bookmarks