PIR Motion sensor detecting without touching

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I have setup my raspberry pi and have inserted the correct wires to the motion sensor, i am currently running a a simple script that detects motion however it constantly outputs that it motion is detected although i have no interacted with the sensor. I am unsure as to what i should do as ive tried numerous things. 

here is the script also:

from gpiozero import MotionSensor
import time

print ("Ready")
pir = MotionSensor(4)
time.sleep(40)
while True:
    if pir.motion_detected:
        print("Motion detected")
        time.sleep(2)

sensorShareEditFollowClose 2Flagasked Apr 26 at 18:40Kazi Ilyas2911 bronze badge New contributor

• what is the purpose of the picture? … please draw a diagram of the connections between the sensor and the RPi – jsotola Apr 26 at 22:32

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3 Answers

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Question

How come my PIR motion sensor output is always High, falsely detects something moving?

Answer

1. Your photo is very nice.
2. I see the PIR motion sensor in the bottom right corner.
3. You motion sensor is very popular, but very unstable.
4. I would recommend to use a good sensor.
5. You might like to read my PIR answer (Ref 1), for more details on:a. How to prove that the PIR is unstable.b. Which stable PIR sensor to use.

References

(1) Why is HC-SR501 PIR motion Sensor always on? Asked 2020, Viewed 3k times

ShareEditDeleteFlaganswered just nowtlfong013,67433 gold badges88 silver badges2222 bronze badgesAdd a comment0

Question

How come my PIR motion sensor output is always High, falsely detecting something moving?

Answer

1. Your photo is very nice.
2. I see your PIR motion sensor in the bottom right corner.
3. This motion sensor, HC-SR501, is very popular, but very unstable.
4. I would recommend to use a very stable sensor, AM302.
5. You might like to read my PIR answer (Ref 1), for more details on:a. How to prove that the PIR is unstable.b. Which stable PIR sensor to use.

References

(1) Why is HC-SR501 PIR motion Sensor always on? Asked 2020, Viewed 3k times

(2) PIR Learning Notes v0.3 – tlfong01 2021apr30hkt1100

ShareEditDeleteFlagedited 5 mins agoanswered 13 mins agotlfong013,67433 gold badges88 silver badges2222 bronze badgesAdd a comment2

That is not a motion sensor. It is a heat detector. If it sees a change in infra-red (heat) it raises an alarm.

As long as you are ‘seen’ by the sensor it will raise an alarm.ShareEditFollowFlaganswered Apr 26 at 19:43joan62.5k55 gold badges6060 silver badges9494 bronze badges

• 1As you said, if it sees a change in IR it will trigger the output. If a warm object is stationery then the sensor sees no change and does not raise an alarm. So, it is a motion sensor if it is a warm object that is in motion. – Elliot Alderson Apr 26 at 21:23 
• 1Yes it is a motion sensor, here is the link of the purchase – thepihut.com/products/… – Kazi Ilyas Apr 26 at 23:54

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