Trouble hooking up a driver

[Daftlander]

I'm trying to make this scanner. https://www.instructables.com/id/Build-a-DIY-Desktop-3d-Scanner-With-Infinite-Resol/

But I'm trying to use an polulu A4988, because that's all I've got hanging around, instead of the big easy driver he has used.

But I can't get my head around the wiring. Do I need a second power source? In the diagram he and photos he seems to be plugging the arduino in and using that to power the motor. Which, as far as I know you cant do with the polulu. 

 

 

 

 

 

 

Thanks for any advice.

[ImAlsoRan]

7 minutes ago, Daftlander said:

I'm trying to make this scanner. https://www.instructables.com/id/Build-a-DIY-Desktop-3d-Scanner-With-Infinite-Resol/

But I'm trying to use an polulu A4988, because that's all I've got hanging around, instead of the big easy driver he has used.

But I can't get my head around the wiring. Do I need a second power source? In the diagram he and photos he seems to be plugging the arduino in and using that to power the motor. Which, as far as I know you cant do with the polulu. 

 

 

 

 

 

 

Thanks for any advice.

Yes, you need at least 8V to the motor with the A4988, which the Arduino doesn’t have. I’m not sure if the board has a pass through for a microcontroller, but I wouldn’t count on it.

[Daftlander]

4 minutes ago, ImAlsoRan said:

Yes, you need at least 8V to the motor with the A4988,

Bugger. So definitely have to buy a big easy then...

 

Thanks! 

[Hackentosher]

In my experience, usually the issue with stepper motors is the current required to drive them. They pull a lot more than a single GPIO pin can provide, thus the driver. Just make sure everything has common grounds and it should be fine.