PIR sensor starts to trigger constantly after some time

[Yveaux]

@LastSamurai you could try with the development branch as I fixed some wake from interrupt issues there; it might solve your issues.
However, I have a comparable experience with cheap pir sensors. Sometimes they trigger when the arduino wakes, probably due to power variation (any other ideas are welcome).
I can imagine that due to changes in amount/order/speed of messages sent in 2.0 this might trigger this strange behavior of the pir sensor.

[LastSamurai]

@Yveaux Thanks for the help, but it seems like the problem got only worse with the development branch. I guess its some kind of hardware problem then. Hopefully my pcb for the ikea motion sensor will arrive soon, then I will try them out.

[abmantis]

Try with a fresh battery! Do you have any step-up converter for the PIR? I've also had the same problem recently, and I think (still need to test a bit more) that it was caused by the battery getting a bit discharged (after an OTA update).

It usually triggers the PIR when the radio sends something. I think it is because the radio makes the voltage fluctuate when it sends.
A simple workaround is to wait 3 seconds (the time my PIR takes to reset/settle after triggering) after sending data, and only then check if it has triggered. But I only wait if the previous state was zero (no motion), since I want it to fire instantaneously when motion is detected. So:

• Get state;
• Send state data;
• If state was 1, sleep 3 secs;
• Send new state if it changed from 0 to 1 (during 3 secs sleep);
• Sleep with interrupt;

[LastSamurai]

@abmantis Thanks for the answer. I think I got most of this. I modified some code from another pir post in this forum.
Here is the code. Is that what you did too?

// library settings
#define MY_RADIO_NRF24
#define MY_DEBUG    // Enables debug messages in the serial log
//#define MY_DEBUG_VERBOSE_SIGNING //!< Enable signing related debug prints to serial monitor
#define MY_BAUD_RATE  9600 // Sets the serial baud rate for console and serial gateway
#define MY_SIGNING_SOFT // Enables software signing
//#define MY_SIGNING_REQUEST_SIGNATURES // Always request signing from gateway
#define MY_SIGNING_SOFT_RANDOMSEED_PIN 7 // floatingpin  for randomness
#define MY_NODE_ID 12

#include <SPI.h>
#include <MyConfig.h>
#include <MySensors.h>
#include <Vcc.h>

// program settings
#define CHILD_ID 1
#define CHILD_ID_BATTERY 2
#define MOTION_INPUT_PIN 3
#define BATTERY_REPORT_DAY 1   // Desired heartbeat(battery report) interval when inactive. 
#define BATTERY_REPORT_BY_IRT_CYCLE 30 // Make a battery report after this many trips. Maximum report interval will also be equal to this number of days.
#define ONE_DAY_SLEEP_TIME 86400000
#define VCC_MIN 1.8
#define VCC_MAX 3.3

int dayCounter = BATTERY_REPORT_DAY;
int irtCounter = 0;

bool interruptReturn = false; // "false" will make the first loop disregard high output from HV-505 (from start-up) and make a battery report instead.
 
Vcc vcc(1.0);
MyMessage msg(CHILD_ID, V_TRIPPED);
MyMessage voltage_msg(CHILD_ID_BATTERY, V_VOLTAGE);


void before() {
  pinMode(MOTION_INPUT_PIN, INPUT);
  digitalWrite(MOTION_INPUT_PIN, LOW);    // Disable internal pull-ups
}

void presentation()  
{  
  sendSketchInfo("Motion sensor", "12112016 v2.0");
  present(CHILD_ID, S_MOTION);
  present(CHILD_ID_BATTERY, S_MULTIMETER);

  sleep(20000); // Wait until HC-505 warmed-up and output returned low.
}

void loop() 
{
  if (interruptReturn) {    // Woke up by rising pin
    send(msg.set("1"));  // Just send trip (set) commands to controller.
    wait(50);
    send(msg.set("0"));  // Send the off command right after
    irtCounter++;
    if (irtCounter >= BATTERY_REPORT_BY_IRT_CYCLE) {
        irtCounter=0;
        sendBatteryReport();
    }
  }
  else { // Woke up by timer  (or it's the first run)
    dayCounter++; 
    if (dayCounter >= BATTERY_REPORT_DAY) {
          dayCounter = 0;
          sendBatteryReport();
    }
  }
  
  sleep(3000);  // Make sure everything is stable before start to sleep with interrupts. (don't use "wait()" here). Tests shows false trip ~2s after battery report otherwise.

  // Sleep until interrupt comes in on motion sensor or sleep time passed.
  interruptReturn = sleep(MOTION_INPUT_PIN-2, RISING, ONE_DAY_SLEEP_TIME);
} 

void sendBatteryReport() {
  wait(50);
  float p = vcc.Read_Perc(VCC_MIN, VCC_MAX, true);
  float v = vcc.Read_Volts();
  int batteryPcnt = static_cast<int>(p);
  sendBatteryLevel(batteryPcnt);
  send(voltage_msg.set(v,3));
}

[abmantis]

My code is a little different, since I only send 0 when the PIR reports 0, instead of sending it right after 1.

If you want I may post the code later.

[LastSamurai]

@abmantis Yes, I did that earlier too, but like this it was easier too use with my controller. Would be great if you could post your code too. Then I could test that too. Really want to get my pir up and working again ;)

[Yveaux]

@LastSamurai a quick test would be to introduce a blind time after triggering by issuing a sleep for a fixed amount of time (e.g 30 secs) without wake from Interrupt.
After this sleep you start another sleep which will wake when the sensor triggers.
I added this to my pir sensors and it works great!

[m26872]

@Yveaux Isn't the "sleep(3000)" already this blind time? But, sure an increase would be good start.

[Yveaux]

@m26872 yup, you're right :smirk: I didn't look at the sketch.
It should indeed wait longer than 3 seconds.

[abmantis]

@LastSamurai Here is the code for my PIR and Light sensore node:
https://github.com/abmantis/MySensors-Sketches/blob/master/MotionLightSensor/MotionLightSensor.ino

It is a bit complex, sorry. Also, ignore the temperature parts since that is a WIP and is untested.