Yet, another project from me. This time, it's about controlling a DC motor, BUT withOUT a H-bridge. It'll use the keyboard to control the motor.
For your reference:
'a' - FORWARD
's' - REVERSE
'd' - BRAKE*
'f' - FREE-RUN*
*The difference between Brake and Free-run is that the Brake function shorts the motor to Ground and finally you'll get to brake. The Free-run function just disconnects the motor terminals with the Arduino and you'll still get to stop but it takes longer as its inertia is still present.
I've used:
 |
| Arduino Uno |
 |
| Breadboard |
 |
| Jumper Wires |
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| DC Motor |
Here is the sketch for the project:
int ad=8; //anode terminal of the motor
int cd=7; //cathode terminal of the motor
int incom; //incoming bytes
void setup(){
Serial.begin(9600); //baud rate - 9600
}
void loop(){
if(Serial.available()){ //if there is incoming bytes
incom=Serial.read(); //that equals to incom
}
switch(incom){
case'a': //if 'a' is pressed
pinMode(ad,OUTPUT);
pinMode(cd,OUTPUT);
digitalWrite(ad,HIGH);
digitalWrite(cd,LOW);
Serial.println("FORWARD"); //the motor goes forward
break;
case's': //if 's' is pressed
pinMode(ad,OUTPUT);
pinMode(cd,OUTPUT);
digitalWrite(ad,LOW);
digitalWrite(cd,HIGH);
Serial.println("REVERSE"); //the motor goes backwards
break;
case'd': //if 'd' is pressed
pinMode(ad,OUTPUT);
pinMode(cd,OUTPUT);
digitalWrite(ad,LOW);
digitalWrite(cd,LOW);
Serial.println("BRAKE"); //the motor brakes
break;
case'f': //if 'f' is pressed
pinMode(ad,INPUT);
pinMode(cd,INPUT);
Serial.println("FREE-RUN"); //the motor goes to free-run mode
break;
default:
Serial.println("Please key in command"); //writes this if no command is present
delay(1000);
break;
}
}
Finally the video. Enjoy!
by Weng Fei
You must be careful with the output current. It is recommended that Arduino I/O pins should only drive up to 40mA per pin. More than that might damage the I/O pin. Most motors will need more than 40mA especially during start-up.
get cheap arduino board in http://smartics.com.my
hey, made an update for a better transition between forward and reverse. If you ground both pins before you switch you will reduce back emf etc.
int ad=8; //anode terminal of the motor
int cd=7; //cathode terminal of the motor
int incom; //incoming bytes
void setup(){
Serial.begin(9600); //baud rate - 9600
}
void loop(){
if(Serial.available()){ //if there is incoming bytes
incom=Serial.read(); //that equals to incom
}
switch(incom){
case'a': //if 'a' is pressed
pinMode(ad,OUTPUT);
pinMode(cd,OUTPUT);
digitalWrite(ad,LOW);
digitalWrite(cd,LOW);
digitalWrite(ad,HIGH);
Serial.println("FORWARD"); //the motor goes forward
break;
case's': //if 's' is pressed
pinMode(ad,OUTPUT);
pinMode(cd,OUTPUT);
digitalWrite(ad,LOW);
digitalWrite(cd,LOW);
digitalWrite(cd,HIGH);
Serial.println("REVERSE"); //the motor goes backwards
break;
case'd': //if 'd' is pressed
pinMode(ad,OUTPUT);
pinMode(cd,OUTPUT);
digitalWrite(ad,LOW);
digitalWrite(cd,LOW);
Serial.println("BRAKE"); //the motor brakes
break;
case'f': //if 'f' is pressed
pinMode(ad,INPUT);
pinMode(cd,INPUT);
Serial.println("FREE-RUN"); //the motor goes to free-run mode
break;
default:
Serial.println("Please key in command"); //writes this if no command is present
delay(1000);
break;
}
}