I am not a n00b to the Raspberry Pi, Python or programming. What I am new to however is using a stepper motor with the Pi.
I am looking to build a CNC machine that I can send a file to over Wireless and launch LinuxCNC (which I have compiled my own kernel) and start cutting.
What I have:
- 3 x Nema17 stepper motors
- 3 x HG7881 H-Bridge drivers
- 1 x Raspberry Pi with a custom LinuxCNC kernel
- All cabling required
The issue I am having is that the Nema17 stepper motors have 4 cables, the HG7881 has 4 inputs and 4 outputs and I have them wired the correct way around according to the polarity of the stepper motor however LinuxCNC only has 2 outputs per stepper motor configured with the Raspberry Pi settings I am using. 1 wire is step and the other is drive. How do I connect the Step/Drive (2 cable) setup from LinuxCNC to the 4 inputs on the HG7881 H-Bridge? Or do I need another piece of hardware in between the Pi and the Stepper motors to replace the H-Bridge, is that where I am going wrong?
This is the H-Bridge that I was talking about:
http://www.ebay.com.au/itm/190866391027 ... 1439.l2649