Miceuz blogged about his DIY driver for EQ2 equatorial mount motor:
We wanted to give a telescope as a Christmas present to one kid. Luckily enough we have happened to find one standing under the autumn rain in a second hand junk yard in Berlin. The telescope itself was dusty and wet, but the mount was in a good shape, just the driver electronics for the motor were missing.
After some poking and googling I was able to determine that the mount uses a bipolar stepper motor to compensate for Earth’s rotation. How do you drive a bipolar stepper? Well, you just hook up a couple of H-bridges and let the microcontroller switch them.I didn’t have enought time to order parts, design and etch the PCB, etc, so I decided to use whatever I had around. The code and schematics are available on my github repo if someone wants to reproduce this or just to poke around.