Previously we have driven servo and DC motor using this simple Arduino motor shield. And we saw how it is easy to interface these motors and write a code. This time we get to real business – stepper motor control. Actually this is what usually motor shields are used for. Stepper motors are more complex devices that require some knowledge. You cannot expect to plug some voltage and see it spinning. Their purpose is stepping, that gives precise control of how much motor is spinning. You can find stepper motor in any printer which feeds paper incrementally – and this is where you can get one. Disk drives is another great source to scavenge. We won’t get in to stepper motor working theory just take a peak on types and working principles before try to run one.
This is a continue of previous post where we have tried to run a servo using arduino motor shield. This was simple task to do with Arduino Servo library. Today we are going to push things a bit forward and drive DC motor using same motor shield. This motor shield is capable of running small DC motors that require less than 0.6A of current and operating voltage us less than 25V. In my drawer I found small 12V motor which will fit for this demo. Before we begin programming, we need to connect motor to the Board. We are going to use M1 connector.: Since motor requires 12V power supply we are going to use external power supply. It can be connected to External power screw terminal. Be sure to remove jumper as well.
Recently I’ve got Arduino motor shield. It is based on ladyada original mshield circuit. It uses two popular L293D quadruple half-H divers. It is cheap and reliable shield to drive various motors. These can be 2 hobby servo motors, 4 bidirectional DC motors or 2 (unipolar or bipolar) stepper motors. Load current is limited to L293D chips. Specification says that each channel can provide constant 0.6A and peak 1.2A. There is also a thermal shutdown to prevent circuit from damaging. Motors can be externally powered using voltage range from 4.5V to 36V. Each motor control channel is pulled down with resistor to disable any motor at power up. In this post we are going to try servo motor control There are couple connectors on motor shield where you can connect two servo motors using standard 3 wire connector (GND, VCC and PWM).