Lately, I've been working on a wireless remote controller for a Robotic Arm. Most of everything is planned out, but I don't have all the parts and shields yet, so I decided to begin prototyping with a single motor. I am using two Xbee radios for wireless communication. As there are 5 motors and an LED, there aren't enough digital pins for me to communicate in that way, so am using Serial communication from Arduino 1 > Xbee 1 > Xbee 2 > Arduino 2.

So, I decided to make simulations of this but with one wired Arduino. In this Instructable I will be demonstrating how to change a DC motor's direction, using both Serial Commands and commands from buttons. Let's get started, shall we?

Step 1: Setup

Software

In this step, I will provide a parts list and a link to download the Arduino software. I used Arduino Create for this project. You can do the same thing with the Arduino program, which is available for download here.

Parts List:

Arduino Uno (other boards may be used)
Standard DC motor
L293DNE H-Bridge
2 Push Buttons
Jumper Wires
Breadboard

All of these items can be easily bought online for a very cheap price.

Step 2: Serial Communication - the Wiring

First, let's work on the Serial communication. Wire up the Arduino as demonstrated.

Step 3: Serial Communication - the Code

Now that you have your Arduino wired up, copy and paste this code into the Arduino IDE. What this code does is read for a signal that you would manually type into the Serial monitor. When either 1 or 2 is entered, the motor would turn either clockwise or counterclockwise for a short period of time. Experiment a little! Type in multiple 1's or 2's and see what happens!

int in1pin = 6;
int in2pin = 7; // connections to H-Bridge, clockwise / counter
char receivedChar; // store info
boolean newData = false; // create a true/false statement
void setup() {
  pinMode(in1pin, OUTPUT);
  pinMode(in2pin, OUTPUT); // set pins to OUTPUTS
  Serial.begin(9600); // start up serial communication
  
}
void loop() {
  recvData(); // read and store data
  moveMotor(); // move motor according to data and then reset
  
}
void recvData() {
  if (Serial.available() > 0) { // if the serial monitor has a reading
    receivedChar = Serial.read(); // set char to be what is read
    newData = true; // make statement true
    
  }
  
}
void moveMotor() {
  int motordirection = (receivedChar - '0'); // turn recieved data into usable form and give it a name
  while(newData == true) {
    Serial.println(motordirection); // print motor direction
    if (motordirection == 1) { // if it reads 1...
      digitalWrite(in1pin, HIGH); // turn motor one way
      digitalWrite(in2pin, LOW);
      delay(250);
      
    }
    else if (motordirection == 2) { // if it reads 2...
      digitalWrite(in1pin, LOW); // turn motor other way
      digitalWrite(in2pin, HIGH);
      delay(250);
      
    }
    else { // if nothing is read
      digitalWrite(in1pin, LOW); // motor is off
      digitalWrite(in2pin, LOW);
      
    }
    newData = false; // reset value to false
    
  }
  
}

Step 4: Button Commands - the Wiring

For button communication, add buttons as shown.

Step 5: Button Commands - the Code

Now, make a new sketch and copy and paste this code, and play around.

int in1pin = 6;
int in2pin = 7; // h bridge pins
int leftButton = 8;
int rightButton = 9; // buttons
void setup() {
  pinMode(in1pin, OUTPUT);
  pinMode(in2pin, OUTPUT); // outputs
  pinMode(leftButton, INPUT_PULLUP);
  pinMode(rightButton, INPUT_PULLUP); // inputs w internal pullup resistors
  
}
void loop() {
  int leftPinState = digitalRead(leftButton);
  int rightPinState = digitalRead(rightButton); // set value names for read data
  if (leftPinState == LOW) { // if left button is pressed ... 
    digitalWrite(in1pin, HIGH); // make motor go one way
    digitalWrite(in2pin, LOW);
    
  }
  else if (rightPinState == LOW) { // if right button is pressed ...
    digitalWrite(in1pin, LOW);
    digitalWrite(in2pin, HIGH); // make motor go other way
    
  }
  else { // if neither button is pressed ...
    digitalWrite(in1pin, LOW); // nothing happens
    digitalWrite(in2pin, LOW); 
    
  }
  
}