Smart Object Detection Alarm Project

Portable DIY Object Detection Alarm Kit (BC557, TP4056) Overview: A compact DIY object-detection alarm kit that uses an R Obstacle Avoidance Sensor Module and a BC557 transistor to boost the trigger signal. When an object is detected the 5V active buzzer sounds. Powered by a single 18650 rechargeable cell with TP4056 charging and a 3.7V→5V boost converter for stable 5V output—ideal for school science projects and small online shop listings. Specifications Sensor: R Obstacle Avoidance Sensor Module (object detection) Transistor: BC557 PNP (signal boost) Buzzer: 5V Active Buzzer (alarm output) Base resistor: 1 kΩ (limits transistor base current) Battery: 18650 Rechargeable 3.7V Li-Ion cell (solderable) Battery holder: 1-chamber 18650 holder Charger: TP4056 1A Li-Ion charging module Power conversion: 3.7V to 5V Multi-Function Mini Boost Step-Up Module Switch: 6-pin slide switch 50V 0.5A DPDT (power on/off) Interconnect: Slim flexible project wire cable Use case: DIY science project, educational demo, portable alarm prototype