RETIRED - SparkFun Inventor's Kit Experiment Guide - v4.0

Last, the switch is not polarized. It works the same no matter its orientation.

Ready to start hooking everything up? Check out the circuit diagram and hookup table below to see how everything is connected.

Circuit Diagram

Hookup Table

Open the Sketch

To open the code, go to: File > Examples > SIK_Guide_Code-V_4 > SIK_Circuit_5A-MotorBasics.

You can also copy and paste the following code into the Arduino IDE. Hit upload, and see what happens!

language:cpp
/*
SparkFun Inventor’s Kit
Circuit 5A - Motor Basics

Learn how to control one motor with the motor driver. 

This sketch was written by SparkFun Electronics, with lots of help from the Arduino community.
This code is completely free for any use.

View circuit diagram and instructions at: https://learn.sparkfun.com/tutorials/sparkfun-inventors-kit-experiment-guide---v40
Download drawings and code at: https://github.com/sparkfun/SIK-Guide-Code
*/

//PIN VARIABLES
//the motor will be controlled by the motor A pins on the motor driver
const int AIN1 = 11;           //control pin 1 on the motor driver for the right motor
const int AIN2 = 12;            //control pin 2 on the motor driver for the right motor
const int PWMA = 13;            //speed control pin on the motor driver for the right motor

int switchPin = 7;             //switch to turn the robot on and off

//VARIABLES
int motorSpeed = 0;       //starting speed for the motor

void setup() {
  pinMode(switchPin, INPUT_PULLUP);   //set this as a pullup to sense whether the switch is flipped

  //set the motor contro pins as outputs
  pinMode(AIN1, OUTPUT);
  pinMode(AIN2, OUTPUT);
  pinMode(PWMA, OUTPUT);

  Serial.begin(9600);                       //begin serial communication with the computer

  Serial.println("Enter motor speed (255, 0, or -255)... ");    //Prompt to get input in the serial monitor.
}

void loop() {

  if (Serial.available() > 0){          //if the user has entered something in the serial monitor
    motorSpeed = Serial.parseInt();     //set the motor speed equal to the number in the serial message

    Serial.print("Motor Speed: ");      //print the speed that the motor is set to run at
    Serial.println(motorSpeed);
  }

  if(digitalRead(7) == LOW){            //if the switch is on...
      spinMotor(motorSpeed);
  } else{                               //if the switch is off...
      spinMotor(0);                   //turn the motor off
  }


}

/********************************************************************************/
void spinMotor(int motorSpeed)                       //function for driving the right motor
{
  if (motorSpeed > 0)                                 //if the motor should drive forward (positive speed)
  {
    digitalWrite(AIN1, HIGH);                         //set pin 1 to high
    digitalWrite(AIN2, LOW);                          //set pin 2 to low
  }
  else if (motorSpeed < 0)                            //if the motor should drive backwar (negative speed)
  {
    digitalWrite(AIN1, LOW);                          //set pin 1 to low
    digitalWrite(AIN2, HIGH);                         //set pin 2 to high
  }
  else                                                //if the motor should stop
  {
    digitalWrite(AIN1, LOW);                          //set pin 1 to low
    digitalWrite(AIN2, LOW);                          //set pin 2 to low
  }
  analogWrite(PWMA, abs(motorSpeed));                 //now that the motor direction is set, drive it at the entered speed
}

What You Should See

When you flip the switch, the motor will turn on and spin at the speed set by the motor speed variable (default is 0). By opening the serial monitor and sending numbers, you can change the speed of the motor. Any number from about 130 to 255 or -130 to -255 will work, though changes in the speed will be hard to notice. Send the number 0 to stop the motor. Adding a piece of tape to the motor shaft makes it easier to see it spinning.

Program Overview

1. Check to see if a command has been sent through the Serial Monitor. If a command has been sent, then set the motor speed to the number that was sent over the Serial Monitor.
2. Check to see if the switch is ON or OFF. a. If the switch is ON, drive the motor at the motor speed. b. If the switch is OFF, stop the motor.

Code to Note

Coding Challenges

Troubleshooting