Connecting a 5V DC and a 12V DC motor to Arduino using L293D

Controlling a single 5V DC motor, and a 12V DC thru an Arduino.

Both are same connections -except that for a 5V, the Vss Motor Supply ( pin 8) will be fed 5V from the wall adapter
for a 12V, the Vss will be fed 12Vwall adapter, and the GND will be common across all.

Connect Pins 8 and 9 of the Arduino to Pins 3 and 7 of the L293D

Arduino   L293D
Pin 8      Pin 7
Pin 9      Pin 2

GND ->       GND // or else it wont work

        Pin 4 -> GND
             Pin 5 -> GND
        Pin 1 -> +5V
        Pin 16-> +5V ( or tie them up)

            Pin 3 -> Output to Motor
        Pin 6 -> Output to Motor
       
        Pin 2, and 7 ( as described above, goes to Arduino Pins 8 and 9)
             Pin 8 -> motor supply +5V ( Pin 1, 16 and Pin 8 - can all be tied to +5V)

For a 5V motor
  Pins 1..8 on left and Pin 16 are connected to connect a single DC motor in case of a 5V.)
   Pin 8 -> +5V ( all of them as 5V )

For a 12V motor
 Check 1 and 16 are internal - so 5V.
  Pins 8 is +12V




For a 5V DC motor.




For a 12V DC motor.




void setup()
{
    pinMode(8,OUTPUT) ;  //Logic pins are also set as output
    pinMode(9,OUTPUT) ;
    Serial.begin (9600);
}

void loop()
{
    forward_motor ();  
    delay(3000) ;    
    stop_motor ();
    delay(3000);
   
    backward_motor ();
    delay(3000);
    stop_motor ();
    delay(5000);
       
 }
 void forward_motor () {
 
    Serial.println ("forward");
    digitalWrite(8,HIGH) ;
    digitalWrite(9,LOW) ;

 }
 void stop_motor ()
 {
     // Stop
    Serial.println ("Stop " );
    digitalWrite(8,LOW) ;
    digitalWrite(9,LOW) ;
 }
 void backward_motor ()
 {
    Serial.println("backward");
    digitalWrite(8,LOW) ;
    digitalWrite(9,HIGH) ;
   }