2 servo's with 2 switches on Arduino Duemilanove

Forum 2005-2010 (read only) Hardware Interfacing
1

I'm building a rover with use of the Arduino Duemilanove. But I can't let it work.
Hopefully someone here could help me.

Connections on Arduino
Pin 9 Servo1
Pin 10 Servo2
Pin 3 Switch1
Pin4 Switch2

The servo's are customised so they won't stop at 180°.
My purpose with this is the following:

If Switch1 + Switch2 are low that Servo1 will turn right and Servo2 turn left.
If Switch1 is high and Switch2 is low that Servo1 + Servo2 turn left.
If Switch2 is high and Switch1 is low that Servo1 + Servo2 turn right.
If Switch1 + Switch2 are high that Servo1 will turn left and Servo2 turn right.

Down here is the code I use:

#include <Servo.h>
Servo myservo1;
Servo myservo2;
int switch1Pin = 3;
int switch2Pin = 4;
int val = 0;
int val1 = 0;

void setup ()
{
pinMode(switch1Pin, INPUT); //pin 3 input
pinMode(switch2Pin, INPUT); //pin 4 input
myservo1.attach(10);
myservo2.attach(9);

}
void loop()
{
val = digitalRead(switch1Pin);
val1 = digitalRead(switch2Pin);
if (val == HIGH){
myservo2.write(179);
}
if (val1 == HIGH){
myservo1.write(0);
}
if (val == LOW){
myservo2.write(0);
}
if (val1 == LOW){
myservo1.write(179);
}

}

If I load this code in the Arduino the Servo's will not work properly. If the switches are low then servo1 turn right and servo2 turn left. If I make one switch high then nothing happens.
If I make them both high, sometimes the servo's will go the orther way for 2 seconds. Then they stop. It looks like that the Arduino is thinking and then the servo's will go the other way.
If I make the switches high again the Arduino does not react.
What am I doing wrong? Or what am I forgotten?

Sorry for my bad english ::slight_smile:

2

You don't say how your switches are wired, but it could be you need to use some pull-up resistors.
Pull-ups can be enabled by calling "digitalWrite (switch1Pin, HIGH);" etc after you've set the pin as an input.
You could simplify your code with an "else":

if (val == HIGH){
    myservo2.write(179);   
} else {
    myservo2.write(0);   
}

if (val1 == HIGH){
    myservo1.write(0);   
} else {
    myservo1.write(179);   
 }

Don't forget that "loop" repeats very quickly, so you may need to put in some delays to see any effect.