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PIR sensor module for Arduino and other microcontroller projects
The HCSR501 is a PIR (Passive Infra-Red) sensor that can detect the presence of people by measuring the infrared radiation radiated by the body. It can be used in a vast and diverse number of projects, including but not limited to: automated lighting systems, burglar alarms, automated door systems, etc.
Principle of operation
All objects with a temperature above absolute zero (0 kelvin) emit electromagnetic radiation. The higher the temperature of the object, the smaller the wavelength of the radiation emitted. The normal human body temperature is 37°C (310.2 kelvin) and it therefore emitts infrared radiation (mostly at a wavelength of 12µm). The PIR sensor can sense when a person has walked into its field of view by measuring the difference in the infrared radiation received from the ambient environment and the human body.
Voltage : 5-20VDC
Power Consumption: 64mA
Logic output: 3.3V
Range: 7 metres, (<120°)
Lock Time: 200 miliseconds
Operating temperature range: between -15°C and 70°C