/*

This code below will check and do something if any sensor is triggered.
If more than one sensor is triggered then the code will still execute and
potentially cause conflicts e.g. the servo wants to turn both left and right!

*/

if (digitalRead(pinPIRright) == HIGH) {
// do stuff when right
}

if (digitalRead(pinPIRleft) == HIGH) {
// do stuff when left
}

if (digitalRead(pinPIRfront) == HIGH) && (digitalRead(pinPIRright) == HIGH)) {
// do stuff when front and right
}

if (digitalRead(pinPIRfront) == HIGH) && (digitalRead(pinPIRleft) == HIGH)) {
// do stuff when front and left
}

if (digitalRead(pinPIRfront) == HIGH) {
// do stuff when front
}

/*

Better way is to use an ‘else’ clause so that the events are specifically controlled.
This way we can have a designated single result/state so there will be no conflict.
This way should also ignore any other combinations we don’t want e.g left and right

*/

if (digitalRead(pinPIRright) == HIGH) {
// do stuff when right
} else {

if (digitalRead(pinPIRleft) == HIGH) {
// do stuff when left
} else {

if (digitalRead(pinPIRfront) == HIGH) && (digitalRead(pinPIRright) == HIGH)) {
// do stuff when front and right
} else {

if (digitalRead(pinPIRfront) == HIGH) && (digitalRead(pinPIRleft) == HIGH)) {
// do stuff when front and left
} else{

if (digitalRead(pinPIRfront) == HIGH) {
// do stuff when front
}
}
}
}
}

left. //turning left
Left,front. //between left and front
Front. // 90 deg. Only when front is only PIR on
Right,front. //between right and front
right. //turning right
,so there is “four positions” will the sketch I have work?
Thanks so much for your help I’m very thankful

If I’ve got that correct (apologies if I’m wrong) then first of all you’ll need to first check that the servo moves left and right depending on the sensor ensuring that motion is only detected on one side.

It depends on how your circuit is configured of course so you may want to change this around slightly, also a typical servo has 180 degrees of movement, so I always calculate that range so I know exactly where its meant to be.

The code below should do left or right and stop if the front is triggered:

if (digitalRead(pinPIRfront) == LOW)) {
// providing the front PIR is not detecting then we can look at left and right.
if (digitalRead(pinPIRleft) == LOW) {
// double check nothing is detected on the left
if ((pos = 1) && (digitalRead(pinPIRleft) == HIGH)) {
pos -= 1;
myservo.write(pos);
delay(15);
}
}
} // else if the front is detecting we can do other stuff now.

So if thats working correctly, you should see your servo turn left on the left sensor etc… I do a check first to see if the right sensor is not detecting motion – but this was originally because I had 2 sensors (I still do!) also it safegaurds against a double positive result – if both trigger then what?

Hope that helps you out – otherwise I’ll get another PIR and buid the circuit up myself

#include
Servo myservo;
int pos = 0;
int pinPIRleft = 4;
int pinLEDleft = 8;
int pinPIRright = 2;
int pinLEDright = 10;
int pinPIRfront = 5;
int pinLEDfront = 7;

void setup() {
pinMode(pinLEDleft, OUTPUT);
pinMode(pinLEDright, OUTPUT);
pinMode(pinLEDfront, OUTPUT);
pinMode(pinPIRleft, INPUT);
pinMode(pinPIRright, INPUT);
pinMode(pinPIRfront, INPUT);
myservo.attach(9);
}

void loop() {

if (digitalRead(pinPIRleft) == LOW) {
digitalWrite(pinLEDleft, HIGH);
if ((pos = 1) && (digitalRead(pinPIRleft) == HIGH)) {
pos -= 1;
myservo.write(pos);
delay(15);
}
} else {
digitalWrite(pinLEDright, LOW);
}

if ((digitalRead(pinPIRleft) == LOW) && (digitalRead(pinPIRright) == LOW)) {

}
}

I’m stuck on the servo moving part, I want to make it so when the front PIR is on the sensor stops in its place until PIR left or right is the only one on please help me wright the last bit

You can use any of these parts in the US it’ll all work the same so there’ll be no difference at least not at this level. In fact you’ll probably find it much easier to get parts in the US – checkout sparkfun.com they have a few bits.

You’ll be glad to know I’m a complete novice and if I can do these projects then anyone can – I’m mainly a programmer so I’m now beginning to find my limits when dealing with schematics and electronics.

Regarding the sketch you could easily add in another few PIR sensors and LEDs. Let me know how you get on and I’ll give you a hand if you get stuck.

Larry.