In the
beginners section we learned about the basics of what stepper motors
can do. This section will look at the Robologic stepper motor and
discover how to program it.
The
Robologic stepper motor is a four phase unipolar motor with a step
angle of 7.5 degrees. It has 6 wires coming from it in 2 sets of 3.
Each set is connected to its own winding. The central pin is the
ground pin, and the 2 pins to the left (pin 1) and right (pin 2) are
connected to each winding. The arrangement is the same on the second
set of pins.
The Robocore can
control up to 2 stepper motors using its standard dc motor
connections. To follow this example attach pin 1 and 2 to the
Robocore's first motor output and pins 3 and 4 to the second motor
output. The two ground pins can be connected together and attached
to the batteries negative terminal.
The
following sequence steps the motor through one complete cycle.
Step |
Pin1 |
Pin2 |
Pin3 |
Pin4 |
1 |
ON |
OFF |
ON |
OFF |
2 |
ON |
OFF |
OFF |
ON |
3 |
OFF |
ON |
OFF |
ON |
4 |
OFF |
ON |
ON |
OFF |
1 |
ON |
OFF |
ON |
OFF |
The
motor can be made to rotate anticlockwise by stepping backwards
through the sequence. I.E. Step 4,3,2,1,4,3 etc |