6pcs HC-SR501 High Sensitivity Human Infrared Sensing Module Pyroelectric Infrared Sensor Compatible with Raspberry Pi

Product Overview:The HC-SR501 is an infrared-based automatic control module designed with the LHI778 sensor, known for its high sensitivity and strong reliability. It operates in a voltage-controlled mode and is widely used in various automatic sensing devices, particularly in battery-powered automatic control products.Product Name: HC-SR501 PIR Motion Sensor ModulePCB Dimensions: 32mm (L) × 24mm (W) × 18mm (H) / 1.26in × 0.94in × 0.71inLens Diameter: 23mm / 0.91inProduct Weight: 6.4g / 0.23ozOperating Voltage Range: 4.5-20V DCStatic Current: ＜ 50uAOutput Level: High 3.3V / Low 0VTrigger Modes:L: Non-repeatable triggerH: Repeatable trigger (default setting)Delay Time: 0.5-200 seconds (adjustable) — can be set to range from fractions of a second to several minutes.Block Time: 2.5 seconds (default) — can be set to range from fractions of a second to several seconds.Sensing Angle: ＜100° cone angleSensing range: within 7 meters/23ftOperating Temperature: -15°C to +70°CUsage Instructions:Initialization:After powering on, the module requires about one minute for initialization. During this time, it may output signals 0-3 times intermittently. After the initialization phase, the module enters standby mode.Avoid Interference:Try to avoid direct exposure of the sensor lens to sources of light, such as lamps, as this might introduce interference signals and cause false triggering.The environment should also avoid moving air, as wind can interfere with the sensor's performance.Sensor Mechanics:The module uses a dual-element sensor. The sensor window is rectangular, with two elements (A and B) located at opposite ends of the long side. When a person moves from left to right or right to left across the sensor, the infrared spectrum reaches the two elements at different times and distances, creating a differential signal. The greater the difference, the more sensitive the sensor becomes.However, if a person approaches the sensor directly (front-to-back) or moves up or down across its field of view, there is no change in the infrared spectrum distance between the two elements, resulting in poor or no detection.Installation Tips:To ensure optimal performance, the direction of the sensor's dual elements should be as parallel as possible to the primary direction of human movement. This ensures that the sensor detects the person as they pass across both elements in sequence. (Note: To increase the sensing angle, this module uses a circular lens, allowing detection from all four sides. However, the left and right sides of the sensor remain more sensitive than the top and bottom. Therefore, it is still recommended to follow the above installation guidelines for best results.)

• The working voltage of this module is DC4.5-20V; it has full automatic sensing. When someone enters its sensing range, it inputs a high level; when someone leaves the sensing range, it automatically delays the high level and outputs a low level.
• The application scope of this module: automatic lighting of various activity venues; automatic operation of various sensing electrical appliances; and alarm systems and anti-theft systems in sensitive areas of enterprises, hotels, shopping malls, and warehouses, etc.
• The module has a reserved position for setting photosensitive control (photosensitive control is an optional function, and photoresistors are not installed at the factory. If necessary, please purchase photoresistors separately and install them yourself)
• The module has two trigger modes: L is non-repeatable, H is repeatable; jumper selection, default is H
• The module has a sensing delay time: 0.5-200S (adjustable) can be made in the range of zero seconds to tens of minutes; sensing blocking time: 2.5S (default) can be made in the range of zero seconds to tens of seconds