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Is there any way to wire 2 steppers to a Raspberry Pi with a ULN2803 Darlington chip? (http://www.adafruit.com/products/970) Can you wire multiple ULN2803's with 2 steppers attached? Is there any way to do this with a minimal amount of GPIO? If so, how?

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Almost certainly. Are they unipolar motors? Most of the hobby steppers I've seen come with driver boards containing a variant of the ULN2XXX.

Here a unipolar motor is been driven by a ULN2003A. The inputs are four Pi gpios. You'd need 8 for two such motors.

The software is trivial. The steppers should have timing diagrams to show the order to pulse the coils.

hobby stepper motor driven by ULN2003A

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For last part of the question on minimum GPIO pins, use Shift Register. Need 3 pins (Data, clock, latch).

Traditionally, ready made chips are in the TTL family. Easy for up to a few tens of bits.

Modern varieties of "field-programming-chip" allow you to "design and make your own" (high number of bits, highly complex functions, etc.). Reading 100 pages book may get you started while in-depth application can be complex. If high data bit number shift register (use ready made chip for low bit number) is the requirement, be sure to choose suitable starter-level reading materials.

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