Continuous notifications in blynk though sensors are not connected

Hi…Iam have connected my pir sensor to nodemcu and the notifications are given to the mobile via blynk app. It works absolutely fine.
But when i remove the sensor connections to the nodemcu ( the nodemcu is connected to the power supply) , the notifications still come at very regular intervals. Can i know why this happens?
I think the notifications should not come as the sensor connections are removed. But still it happens. Why?

without much details about your code, mcu, pir sensor etc, nobody can answer this.

maybe you do not use pullup / pulldown resistors and the pins are floating without the sensor connected?

Also possible, becasue the PIR usually requires very specific timing, there may be some minor timer conflicts with the Blynk or any other libraries that also use the timers… thus “false” readings?

As @wanek already stated, without code and much more details (hardware, type of PIR, etc.), we are just guessing.

@Gunner, could you elaborate this? what timing requires a motion sensor? all models i’ve used so far, actuated a relay, or just sent a high / low signal on motion event.

the other thing, if the sensor is disconnected from mcu, how can it interfere with it?

or i’m completely misundestand something… ?

Opps, my mistake :blush:, not a fault of your understanding… I was thinking of the ultrasonic sensors that I have also been playing around with, not the PIR. I call them “ping” sensors, and in a groggy state PIR and PING look the same to me. :sleeping:

Some of the the ultrasonics coding I have played around with use active timer counting, even if the sensor is not there… and I have sometimes experiance “issues” with Blynk if I leave the sensors running all the time… thus I was thinking that might contribute to the “floating” you had already mentioned.

Mental note, finish coffee before typing :stuck_out_tongue_winking_eye:

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Same with my problems. Did you get the solution for this problem?

The OP hasn’t visited this site in over two years, so your chances of getting a reply are slim.

I’d suggest you do what has already been suggested, provide the following:

  • Details of the MCU you are using
  • information about the type of sensor you are using, and how you’ve connected it to your MCU.
  • The code that you’re using (correctly formatted with triple backticks and with your Auth code removed)
  • Details of your app setup
  • Details of which version of the Blynk library, app etc that you are using
  • A clear explanation of the symptoms that you’re experiencing, and any useful information such as the output from your serial monitor.