Introduction You’ve connected a PIR sensor to your Arduino, uploaded a sketch, but nothing happens when you wave your hand. Let’s systematically debug the issue. 1. Verify Hardware Connections The most common mistake is incorrect wiring. For HC-SR501: VCC →…

The Short Answer No, a standard PIR sensor will not work reliably behind glass. Glass is opaque to the mid-infrared wavelengths (8-14 μm) that PIR sensors detect. Why Glass Blocks Infrared Ordinary glass (soda-lime glass) is transparent to visible light…

Introduction Using PIR sensors outdoors opens a world of possibilities—security lights, gate openers, wildlife cameras—but also introduces new problems. Here’s how to tackle common outdoor issues. 1. Rain and Moisture Water on the lens can scatter infrared and cause false…

Introduction A PIR sensor that only detects motion at close range may be ineffective for your application. Before replacing it, try these methods to maximize its detection distance. 1. Adjust the Sensitivity Potentiometer Most PIR modules have a potentiometer labeled…

Introduction Few things are more frustrating than a motion sensor that triggers for no apparent reason. If your PIR sensor is acting up, here are the most likely culprits and how to address them. 1. Heat Sources PIR sensors detect…

Introduction You’ve connected your PIR sensor, uploaded the code, but nothing happens. Or maybe it’s triggering randomly. Don’t worry—most PIR issues are easy to fix. Here are 7 common problems and their solutions. 1. Check Power Supply Symptom: Sensor doesn’t…