Friday, July 27, 2012

A4988 Single Axis Carrier Board

I recently ordered some simple boards from OSH Park.  These are single-axis versions of my 3-axis carrier board for the Pololu A4988 stepper carriers and (will) include pulldown resistors for the microstepping pins (which can be set using DIP switches), as well power and pull-down resistors for high- and low-limit switches.  All connections are made using 3.5mm screw terminals and the boards have mounting holes for more permanent installation.  They also feature a diode for reverse voltage protection on the logic supply (but not on the motor supply).

A quick test seems to indicate that the boards are electrically sound, although I have yet to fully populate one and test it fully.  If they work properly, I plan to fix a silkscreen error where the logic supply voltage and ground connections are unlabeled.  I also plan to break out the enable pin on the driver and the large capacitor across the motor supply suggested by the Pololu site.  When I'm content with how the boards work, I'll release the Eagle files.

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