Disabling the A4988

Good evening all,

I have the X5 board (and love it), however I have made a daughter board to allow me to use external drivers. This daughter board literally takes the driver breakout from the Smoothie, routes them to the new driver. Then drops them back onto the smoothie in position of the A4988.

For example M1 breakout goes to the daughter board, then the motor outputs are returned into the M1 output pins.

However, an over site on my behalf, i neglected to check if the A4988 can be disabled and not interfere with the external drivers.

Looking at the A4988 datasheet, pulling Enable to ground will disable the A4988’s outputs. However I notice that there is a resistor for the Sleep pin (for example R24), driving this pin high.

Any body know if removing this resistor and then pulling Sleep to ground would prevent any conflict between the two drivers?

I know its a long shot and thank you all in advance.


Mr D

Imported from wikidot


Once this issue is solved I will post the PCB for the daughter board if anyone is interested (will need some modding though)….

If you want a solution that doesn’t require de-soldering something, simply have your external drivers always enabled, and disable the on-board driver …