PIR Motion Sensor

Description

The motion sensor, sometimes known as a Passive Infrared (PIR) has an integrated circuit and a lens that will focus the moving objects for the sensor. A motion sensor has a 3.3V digital output so can connect directly to a Raspberry Pi or Arduino digital input pin.

Tutorial

http://www.projects.privateeyepi.com/home/home-alarm-system-project/installation

Functional Details

Take note of the various features of this very configurable sensor.
 - VCC,OUT and GND are the power, output and ground pins.
 - VCC goes to the 5V+.
 - You can use pin 2 (5V) on the Raspberry Pi however it is best not to draw too much power from the Pi. I prefer giving sensors their own power.
 - GND goes to pin 6 on the Pi (ground).
 - OUT goes to the two resistors (10k and 1k) as per the privateeyepi_alarm_circuit.jpg diagram
 - The Time delay control is very useful for adjusting (use scredriver) how long you want the PIR to wait before it resets itself after motion is detected. All the way clockwise is 5 minutes (probably too long). I set it almost all the way anti clockwise to around 10-20 seconds
 - The Distance adjustment can be used to fine tune the focal distance of the sensor. I find that if it is turned too far clockwise then it becomes too sensitive and sends erroneous signals. Its best to set it also all the way anti clockwise. If you are getting false alarms then usually this is set to be too sensitive (clockwise).
 - Lastly, set the dip switch to Non-repeatable trigger mode. If you don't do this then it will send multiple hits very fast to our server and it will likely crash the alarm.py application.

Features

• Product Type: HC--SR501 Body Sensor Module
• Operating voltage range: DC 4.5-20V
• Quiescent Current: <50uA
• Level output: High 3.3 V /Low 0V
• Trigger: L can not be repeated trigger/H can be repeated trigger(Default repeated trigger)
• Delay time: 5-200S(adjustable) the range is (0.xx second to tens of second)
• Block time: 2.5S(default)Can be made a range(0.xx to tens of seconds
• Board Dimensions: 32mm*24mm
• Angle Sensor: <100 ° cone angle
• Operation Temp: -15-+70 degrees
• Lens size sensor: Diameter:23mm(Default)