PIR motion sensor module

Model: HC-SR501.
PIR motion sensor module.
PIR sensors have the function of detecting movement (of people), normally it seeks to detect the movement of a person within the range of the sensor. They are cheap, small, low consumption and easy to use, also they do not wear out. Normally we can find them in household appliances and gadgets for the office or home. They are known as PIR, “Infrared Sensors” or “Motion Sensors”.

This module contains a Pyroelectric sensor, which can detect changes in infrared radiation. Every object (or human body) emits a certain level of radiation, and the higher the temperature, the more radiation it will emit. The sensor inside the motion detector is divided into 2 halves or 2 sides. The reason for this is that we are looking for the difference in movement, not the average. The two halves are linked by cables so that they cancel each other out. If one half receives more or less IR radiation, the output will change to High or Low.

PIR sensors are perfect for detecting when a person enters or leaves a space, from this we can program different actions such as the automatic turning on/off of lights, sounds, alarms, text messages, calls, etc. Although they are capable of detecting people, they cannot tell us how many, or in which direction they are, and in some cases it can be activated by pets, the key is to experiment and find the sensitivity values that work properly.

The HC-SR501 PIR module has 2 potentiometers that allow you to regulate the sensitivity and duration of the pulse. It also has some jumpers to configure the mode of the output signal. Using the PIR module with Arduino is very simple, we just have to declare it as a digital input or as a hardware interrupt on pins 2 or 3 for the Arduino Uno.

Specifications:
Dimension: 3.2cm x Color: White + Green
Dimension: 3.2cm x 2.4cm x 1.8cm (approx)
Infrared sensor with control circuit board
Sensitivity and retention time can be adjusted.
Working voltage range: DC 4.5V- 20V
current drain: <60uA

Voltage output: High/Low level signal: 3.3V TTL output
Detection distance: 3--7M (can be adjusted)
Detection range: <140°
Delay time: 5-200S (can be adjusted, default 5s + -3%)
Block Time: 2.5 s (default)
Trigger: L: Non-repeatable trigger H: Repeat trigger (default)
Working temperature: -20-+80°C
Size: 2.4cm x 1.8cm (approximate)