[SOLVED]RadioShack PIR Sensor never gives values

Troubleshooting
1

I am using a Radioshack PIR with Gnd -> Gnd , VOC -> 3v3 OUT->D6 and even with code as simple as

int inputPin = D6;              // choose the input pin (for PIR sensor)

void setup()
{
    Serial.begin(9600);
    pinMode(inputPin, INPUT);     // declare sensor as input
}

void loop(){
  Serial.println(digitalRead(inputPin));
}

and I try to connect to serial monitor I keep getting the red flash and it disconnects me. Any idea what could be happening?

2

You may want to try powering it with Vin (5V).

3

Hmm, not entirely sure why that wouldn’t work. You could try giving it some time to calibrate before polling it. Could you try this code:

/*
 * Connected sensor
 * Spark.publish() + PIR motion sensor = awesome
 * Thanks to Adafruit for the reference and inspiration
 */

int inputPin = D6;              // choose the input pin (for PIR sensor)
int pirState = LOW;             // we start, assuming no motion detected
int val = 0;                    // variable for reading the pin status
int calibrateTime = 10000;      // wait for the thingy to calibrate

void setup() {
  pinMode(inputPin, INPUT);     // declare sensor as input
  Serial.begin(9600);
}

void loop(){
  if (calibrated()) {
    readTheSensor();
    reportTheData();
  }
}

bool calibrated() {
  return millis() - calibrateTime > 0;
}

void readTheSensor() {
  val = digitalRead(inputPin);
}

void reportTheData() {
  if (val == HIGH) {
    if (pirState == LOW) {
      // we have just turned on
      Serial.println("Motion detected!");
      Spark.publish("PIR_SENSOR_TRIGGERED!");
      // We only want to print on the output change, not state
      pirState = HIGH;
      RGB.control(true);
      RGB.color(0,255,0);
      delay(2500);
      RGB.control(false);
    }
  } 
  else {
    if (pirState == HIGH) {
      // we have just turned of
      Serial.println("Motion ended!");
      // We only want to print on the output change, not state
      pirState = LOW;
    }
  }
}

It’ll output over Serial, will blink the onboard LED and will send out a SSE. Should give you some visual confirmation. @BulldogLowell’s suggestion is also worthwhile trying, although the sensor should work with 3.3V as well, according to the datasheet, but you never know…
Let me know if that worked for you.

4

@Moors7
Silly question but where is the 5V pin? I do not have this connected to a breakout board rather a bread board.

5

if connected over USB, the Vin pin will supply 5V :slight_smile:

1 Like
6

Gotcha will try when I get home
:smile:

7

I had a similar experience with an Seeed pir. Specs say 3-5vdc, but it wasn’t at all stable @ 3V.

8

Ok so 5v and the code above by @Moors7 worked like a charm. Sorry, my photon was getting the famous “cannot compile code” error.

1 Like