H Bridge as stepper driver

UPDATE: This page is out-dated and works only with the Grbl v0.7 branch. Grbl doesn't officially support H-bridge drivers and recent versions do not work with this code. There are also have been too-many-to-list bug fixes pushed since v0.7. But if you have updated code to work with the new versions, please let us know!

GRBL can also be used to create the step pulses. This allows simple transistor arrays such as the uln2003 to be used as stepper driver. Example wiring can be found here.

Only 3 files need to be changed. Support for limit switches is removed because all i/o pins are used for the motors. The code is here.

The pin definitions can be adjusted in stepper.c

This setup does not have current limiting!