Reply To: Stepper Driver Current Limit & parallel Stepper Motors

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#6716

AH
Participant

Hello,

I’m building one of this amazing CNC’s. I’m on a electronic phase (previously I did a Cyclone PCB engraving using a 4988 + Ramps 1.4).
On this CNC I’m using a DRV8825 steep drivers on RAMPs 1.4, as recomended, but I have some questions.
I did a comparation of the pinouts between the A4988 and DRV8825 and i found some differences:
a) On Ramps using A4988, nSLEEP and nRESET signals are just conected together –> on DRV8825 Polulu manual, the same signals must be connected to VDD +5V.
b) On Ramps the VDD is supplied to A4988, this pin it’s a nFault signal on the DRV8825 (output signal). That means we are connecting a output signal to a VDD.
https://www.pololu.com/picture/view/0J3360
https://www.pololu.com/picture/view/0J4124
http://reprap.org/mediawiki/images/f/f6/RAMPS1.4schematic.png

Could you pls confirm if I need to do any rewiring/cutting on Ramps, to use the DRV8825 instead A4988, or it’s just replace one by the other?

Thank you in advance.
AH