Welcome! Log In Create A New Profile

Cannot run A4988

Posted by Arnold

Arnold

Cannot run A4988
November 09, 2015 07:54AM

Registered: 10 years ago
Posts: 150

Hi all,
so I connected everything like in this schema:

[www.pololu.com]

but Iam not able to spin the motor. It looks like that motor is even not connected. I meassured current on stepper and there is. Also checked 5V from board and 24 from power supply, its ok.
Is there anything else I have to check ?

Reply Quote

Arnold

Re: Cannot run A4988
November 09, 2015 08:09AM

Registered: 10 years ago
Posts: 150

ok, I did not have connected RESET with SLEEP, but anyway, not motor is working but the steps are so loud, its rattling. How to drive it smoothly ? I changed currect from stepper but it does not work. Motor is nema 17.

Reply Quote

dc42

Re: Cannot run A4988
November 09, 2015 08:20AM

Registered: 10 years ago
Posts: 14,672

Quote
Arnold
ok, I did not have connected RESET with SLEEP, but anyway, not motor is working but the steps are so loud, its rattling. How to drive it smoothly ? I changed currect from stepper but it does not work. Motor is nema 17.

Try enabling microstepping, by connecting the MS1, MS2 and MS3 pins to +5V.

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Reply Quote

Arnold

Re: Cannot run A4988
November 09, 2015 08:36AM

Registered: 10 years ago
Posts: 150

You mean all pins MS1,MS2,MS3 to one 5V on arduino UNO ? Can you tell me more how it works ?

Reply Quote

Arnold

Re: Cannot run A4988
November 09, 2015 09:26AM

Registered: 10 years ago
Posts: 150

Ok, I tried it, microstepping works, but there is still rattling, its not so silent and smooth as it works for example with ramps 1.4 on arduino mega.
So anyone knows ?

Reply Quote

imqqmi

Re: Cannot run A4988
November 11, 2015 12:32PM

Registered: 9 years ago
Posts: 752

Did you try adjusting the motor current using the tiny potmeter on the A4988 step stick?

Also try 12V, I've driven the A4988 using a pic microcontroller using my own code and works well. Also make sure the pulses you supply to the DIR and STEP pins are not too short. Lookup the minimum pulse widths in the A4988 datasheet.