Wiring discrepancy

[schwack]

When connecting the item# 1182 stepper motor to a A4988 Stepper Motor Driver Carrier the driver board order is 2B-2A-1A-1B. According to the FAQ, leads B & D are 2A & 2B, while A & C are 1A & 1B. This would result in a color order of Blu-Red-Blk-Grn down the right side of the carrier.

The motor however is wired Blu-Red-Grn-Blk. According to the instructions, this will make the motor run backwards. This would be true in full step mode, but would result in the coils being energized in the wrong order when microstepping. Should I swap the pins on the motor lead, or is this actually done for a reason?

Minimal wiring diagram for connecting a microcontroller to an A4988 stepper motor driver carrier (full-step mode).

Item #2268 wiring diagram The above diagram shows a standard bipolar stepper motor. To control this with the A4988, connect stepper leads A and C to board outputs 1A and 1B, respectively, and stepper leads B and D to board outputs 2A and 2B, respectively. Note that if you happen to swap which way the wires are connected for any coil, the stepper motor will turn in the opposite direction, and if you happen to pair up wires from different coils, the motor should be noticeably erratic when you try to step it, if it even moves at all. See the A4988 datasheet for more information.

Stepper Motor with 28cm Lead Screw: Bipolar, 200 Steps/Rev, 42×38mm, 2.8V, 1.7 A/Phase

[nathanb]

In general, there is nothing electrically important about which end of a coil in the motor gets connected to which side of the channel on the stepper driver. The only thing that affects is the rotation direction of the motor. As long as you have both sides of one of the coils connected to the #1 channel and both sides of the other coil connected to the #2 channel, the motor will turn.

If you have a system where the motor is moving opposite the desired direction, one solution is to swap the connections to the coils on one of the channels. Alternatively, inverting the logic used to control the DIR pin would have the same practical effect.

The direction the motor moves for a given set of coil connections and a given logic state of the DIR pin does not change between full-step mode and different microstepping modes.

-Nathan