Hi,
I want to control a motor as per following
When I press forward button digitalwrite(4) HIGH
When I press reverse button digitalwrite(5) HIGH
When I press stop button digitalwrite(4) or (5) LOW
I want to run until stop button press.
any help will be highly appreciated.
Thank you,
Nadeeka
Try something, show it here if it does not work and we will help you further. You already have found digitalWrite, how about digitalRead to read your buttons?
void setup() {
// put your setup code here, to run once:
pinMode (13,OUTPUT); // for forward contactor shield
pinMode (12,OUTPUT); // for reverse contactor shield
pinMode (2,INPUT_PULLUP); // for forward push button
pinMode (3,INPUT_PULLUP); // for reverse push button
pinMode (4,INPUT_PULLUP); // for stop push button
}
void loop() {
// put your main code here, to run repeatedly:
if(digitalRead(2)==LOW){
while(digitalRead(4)==LOW);
digitalWrite(13,HIGH);
}
else{
digitalWrite(13,LOW);
}
if(digitalRead(3)==LOW){
while(digitalRead(4)==LOW);
digitalWrite(12,HIGH);
}
else{
digitalWrite(12,LOW);
}
}
this one I tried and it doesn't work.
Please post code between code tags
** **[code]** **
your code here
** **[/code]** **
so it will look like
void setup() {
// put your setup code here, to run once:
pinMode (13, OUTPUT); // for forward contactor shield
pinMode (12, OUTPUT); // for reverse contactor shield
pinMode (2, INPUT_PULLUP); // for forward push button
pinMode (3, INPUT_PULLUP); // for reverse push button
pinMode (4, INPUT_PULLUP); // for stop push button
}
void loop() {
// put your main code here, to run repeatedly:
if (digitalRead(2) == LOW) {
while (digitalRead(4) == LOW);
digitalWrite(13, HIGH);
}
else {
digitalWrite(13, LOW);
}
if (digitalRead(3) == LOW) {
while (digitalRead(4) == LOW);
digitalWrite(12, HIGH);
}
else {
digitalWrite(13, LOW);
}
}
'It does not work' does not mean anything. You need to be far more clear in what you expect it to do and what it actually does.
if (digitalRead(2) == LOW) {
while (digitalRead(4) == LOW);
digitalWrite(13, HIGH);
}
else {
digitalWrite(13, LOW);
}
The above is executed if button 2 (forward; please use sensible names instead of number) is pressed. Next it does not do anything while button 4 (stop) is pressed and next it will activate the forward contactor.
If button 2 is not pressed, you while de-activate the contactor.
What I think that you want is
press forward once, de-activate reverse and activate forward
press reverse once, de-activate forward and activate reverse
press stop once, de-activate both
#define MOTORFORWARD 13
#define MOTORREVERSE 12
#define BTNFORWARD 2
#define BTNREVERSE 3
#define BTNSTOP 4
void setup() {
// put your setup code here, to run once:
pinMode (MOTORFORWARD, OUTPUT); // for forward contactor shield
pinMode (MOTORREVERSE, OUTPUT); // for reverse contactor shield
pinMode (BTNFORWARD, INPUT_PULLUP); // for forward push button
pinMode (BTNREVERSE, INPUT_PULLUP); // for reverse push button
pinMode (BTNSTOP, INPUT_PULLUP); // for stop push button
}
void loop() {
// if forward pressed
if(digitalRead(BTNFORWARD) == LOW)
{
// stop reverse (just in case)
digitalWrite(MOTORREVERSE, LOW);
// go forward
digitalWrite(MOTORFORWARD, HIGH);
}
// if reverse pressed
if(digitalRead(BTNREVERSE) == LOW)
{
// stop forward (just in case)
digitalWrite(MOTORFORWARD, LOW);
// go reverse
digitalWrite(MOTORREVERSE, HIGH);
}
// if stop pressed
if(digitalRead(BTNSTOP) == LOW)
{
// stop forward
digitalWrite(MOTORFORWARD, LOW);
// stop reverse
digitalWrite(MOTORREVERSE, LOW);
}
}
What you need to add is some intelligence if multiple buttons are pressed at the same time; pressing forward and reverse will make the motor go crazy 
Its working perfectly, Thank you very much.
but I cant understand how does its works with #define 
how does its works with #define
Your code
pinMode (13, OUTPUT); // for forward contactor shield
pinMode (12, OUTPUT); // for reverse contactor shield
pinMode (2, INPUT_PULLUP); // for forward push button
pinMode (3, INPUT_PULLUP); // for reverse push button
pinMode (4, INPUT_PULLUP); // for stop push button
#define MOTORFORWARD 13
#define MOTORREVERSE 12
#define BTNFORWARD 2
#define BTNREVERSE 3
#define BTNSTOP 4
Can you see how it works now?
'#define' defines something 
In this case it defines names for pin numbers. So instead of using pin numbers (that you need to remember or look up again) in pinMode and digitalRead and digitalWrite, you can now use sensible names.
Ok, I got that. thank you again.