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This example is for Wiring version 1.0 build 0100+. If you have a previous version, use the examples included with your software. If you see any errors or have comments, please let us know.

Driving a DC Motor by BARRAGAN http://barraganstudio.com
Demonstrates the use a DC Motor motor with the L293D Motor Driver chip. On Wiring v1 boards the PWM capable pins are: 29, 30, 31, 35, 36 and 37 On Wiring S board the PWM capable pins are: 4, 5, 6, 7, 19 and 20

    int motorpin = 4;  // L293D Pin En1 connected to pin PWM 4

    void setup()
    {
      pinMode(motorpin, OUTPUT);
    }

    void loop()
    {
      analogWrite(motorpin, 125);  // turn ON the Motor at medium speed
      delay(100);
    }