Simple DC Motor code? Without motor shield?
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Simple DC Motor code? Without motor shield?

by 1EAS1 on Sun May 05, 2013 3:03 pm

Ok so here's the setup, I have 2 dc motors, 1 in the back for forward/backward and 1 in the front for steering left and right. I just started arduino so Im still in the noob range, but what I had in mind is to control how far or how long each motor will run and then repeat so it runs on a pre-programmed track almost. For example, I would like it to go forward using the forward/backwards motor for say 3 seconds on a certain speed and then turn left using the left and right motor for a certain time on a certain speed then going forward again to achieve that turn. Is there already a code like this? As well, I would like to use a Dual-H bridge how ever its spelt.

Thanks!
-Ethan
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Re: Simple DC Motor code? Without motor shield?

by adafruit_support_mike on Sun May 05, 2013 4:35 pm

Even if you don't use the motor shield itself, you can look at the circuit and the code for suggestions on what to do.

The simplest way to drive a DC motor is just to turn on the power. A half bridge controls power to the motor by creating low-resistance connections to the high or low voltage rails, depending on what you tell it to do.

To make a DC motor turn either direction, connect each wire to its own half bridge. Send half-bridge A HIGH and half-bridge B LOW to make the motor turn one direction, A LOW and B HIGH to make the motor turn the other direction.

To control the motor's speed, you turn the power on and off quickly, using a technique called "pulse-width modulation" or "PWM". Over the long term, a half-bridge that's HIGH 80% of the time and LOW the remaining 20% of the time gives the motor 80% as much power as one that's HIGH all the time.

The Motor Shield has all the hardware and software issues worked out, but like I said, even if you don't use the device itself, the circuit diagrams and the library code give you an example of stuff that's known to work.
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Re: Simple DC Motor code? Without motor shield?

by 1EAS1 on Sun May 05, 2013 8:01 pm

ok thanks!!
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