Page 287 - ARM Based Microcontroller Projects Using MBED

9.5 PROJECT 4—SIMPLE STEPPER MOTOR CONTROL 273

FIG. 9.17 Bipolar stepper motor windings.

TABLE 9.2 Bipolar Motor Excitation

Step a c b d
1 +
2 +
3 +
4 +

FIG. 9.18 Block diagram of the project.

• Operating voltage: 5V
• Number of phases: 4
• Gear ratio: 64
The common pins of the windings are joined together and as a result the motor has only
five terminals. The terminals are identified as follows:

Pin Description
2 (Pink) Winding 1 terminal
4 (Orange) Winding 1 terminal
5 (Red) Winding1+Winding 2 common terminal
3 (Yellow) Winding 2 terminal
1 (Blue) Winding 2 terminal