SLR Sky Tracker Instructions
Bill of Material in PDF
Parts sourced from McMaster Car, Amazon, Stepper Online
Uses PrintRBot Revision F Board. Source and executable included. Instructions on compilation and downloading are available online. Uses Audrino 1.0.5 R2 for the AT90USB1286
Firmware steps at 18.07 steps per second (Simple PID loop in the firmare to achieve floating point step count)
There is 1 Switch for Forwards and 1 Switch for backwards at max rate (To reset the position to start).
These are triggered in the firmware by grounding Port Pins E0 and E1 (Pin #33 and #34 on U6). See Schematic:
These pins route to EXP2, You can solder to the holes or install a header. The pin order is not defined by the schematic, and is wrong on the board print. I suggest you ohm out from U6 to this header to verify the correct pin.