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External Stepper Driver

Release status: Working

Description External Stepper driver slot
License GPL
Author brupje
Based-on Pololu Electronics
Categories Megatronics
CAD Models none
External Link none


The Megatronics boards allows you to connect extra stepper drivers to an axis. This board can take advantage of that feature and allows you to run 2 stepper motors on one axis using two stepper drivers. Or 3. Or 4. Or how much you like, they can be connected in series.

Major features

  1. You can connect (theoretically) unlimited amount of stepper motors to one axis.
  2. Compatible with Megatronics 1.0 and Megatronics 2.0
  3. Compatible with Pololu 498X, Pololu DRV8825 and Stepstick
  4. Easy to assemble and connect



Note: Red circles are +

Name Description
12V input Power input (12v max) You can connect this to the 12v output of Megatronics, when the megatronics is powered by a 12V power supply.
12V output Power output
Stepper motor output Output connector for stepper motor
5V output 5V power output
Data input Input connector (left to right: Enable, Step, Dir, GND)
Data Output Output connector for other external stepper drivers(left to right: Enable, Step, Dir, GND)

Power from 24V

When you want to run this board on 24V, you should not place the 7805 component. Instead you can connect the 5V output connector to the Megatronics 5V output.

Required Components

Designation(s) Name
U1 7805 voltage regulator (Do not place when powered from 24V)
C20,C21,C22 100Uf Capacitor
C14 100nF capacitor
R63 100K Resistor
R90 10K resistor

Assembling and connecting the board


First place the headers. The jumpers control the stepsize (MS0, MS1 and MS2). Refer to the stepper driver documentation for details. If you want to use the DRV8825, you should also jumper the 4th pins.


Place the three capacitors. The long lead should be next to the + sign.


Place the blue capacitor. Orientation doesn't matter.


Place the resistors. Orientation doesn't matter.


Place the 7805 like this. If you want to power the board from 24 skip this step.


Solder the cables to the board, Red wires on the left.


Place the Pololu/Stepstick like this. The Pololu DRV8825 should have the trimpot on the other side.


Place a 4 way header on the Megatronics output connector, for each axis you want to connect


Connect the board to the Megatronics


  1. DesignSpark PCB design File:ExtSTepSources.zip
  2. PCB Design PDF files File:ExtStep - PDF.zip