I am using a PIR motion sensor to control a servo arm. The servo opens and closes the lid on a container. It opens and then stays open for five seconds and then closes until motion is detected once again. Initially it was working well but now the PIR seems to be stuck on HIGH and so when the lid closes it automatically reopens, waits the five seconds and then closes again, and then repeats and repeats. I have checked the wires to make sure everything is correct. I have switched out the PIR and it doesn't make a difference. here is the code I am using ( it is from https://www.instructables.com/Motion-Activated-Servo/ with an added delay for staying open a few seconds.) I am new at this and trying to teach my son. Any help would be appreciated. Thanks.
#include <Servo.h>
Servo myservo; //creates a servo object
//a maximum of eight servo objects can be created
int pos = 0; //variable to store servo position
//amount of time we give the sensor to calibrate(10-60 secs according to the datasheet)
int calibrationTime = 30;
//the time when the sensor outputs a low impulse
long unsigned int lowIn;
//the amount of milliseconds the sensor has to be low
//before we assume all motion has stopped
long unsigned int pause = 5000;
boolean lockLow = true;
boolean takeLowTime;
int pirPin = 12; //digital pin connected to the PIR's output
int pirPos = 13; //connects to the PIR's 5V pin
void setup(){
myservo.attach(4); //attaches servo to pin 4
Serial.begin(9600); //begins serial communication
pinMode(pirPin, INPUT);
pinMode(pirPos, OUTPUT);
digitalWrite(pirPos, HIGH);
//give the sensor time to calibrate
Serial.println("calibrating sensor ");
for(int i = 0; i < calibrationTime; i++){
Serial.print(calibrationTime - i);
Serial.print("-");
delay(1000);
}
Serial.println();
Serial.println("done");
//while making this Instructable, I had some issues with the PIR's output
//going HIGH immediately after calibrating
//this waits until the PIR's output is low before ending setup
while (digitalRead(pirPin) == HIGH) {
delay(500);
Serial.print(".");
}
Serial.print("SENSOR ACTIVE");
}
void loop(){
if(digitalRead(pirPin) == HIGH){ //if the PIR output is HIGH, turn servo
/*turns servo from 0 to 180 degrees and back
it does this by increasing the variable "pos" by 1 every 5 milliseconds until it hits 180
and setting the servo's position in degrees to "pos" every 5 milliseconds
it then does it in reverse to have it go back
to learn more about this, google "for loops"
to change the amount of degrees the servo turns, change the number 180 to the number of degrees you want it to turn
**/
for(pos = 0; pos < 100; pos += 1) //goes from 0 to 180 degrees
{ //in steps of one degree
myservo.write(pos); //tells servo to go to position in variable "pos"
delay(15); //waits for the servo to reach the position
}
delay(5000);
for(pos =100; pos>=1; pos-=1) //goes from 180 to 0 degrees
{
myservo.write(pos); //to make the servo go faster, decrease the time in delays for
delay(15); //to make it go slower, increase the number.
}
if(lockLow){
//makes sure we wait for a transition to LOW before further output is made
lockLow = false;
Serial.println("---");
Serial.print("motion detected at ");
Serial.print(millis()/1000);
Serial.println(" sec");
delay(50);
}
takeLowTime = true;
}
if(digitalRead(pirPin) == LOW){
if(takeLowTime){
lowIn = millis(); //save the time of the transition from HIGH to LOW
takeLowTime = false; //make sure this is only done at the start of a LOW phase
}
//if the sensor is low for more than the given pause,
//we can assume the motion has stopped
if(!lockLow && millis() - lowIn > pause){
//makes sure this block of code is only executed again after
//a new motion sequence has been detected
lockLow = true;
Serial.print("motion ended at "); //output
Serial.print((millis() - pause)/1000);
Serial.println(" sec");
delay(50);
}
}
}
