All posts in the 'security projects' Category
This circuit features automatic Exit and Entry delays - timed Bell/Siren cut-off - and system reset. It has provision for normally-open and normally-closed switches - and will suit all of the usual input devices (Pressure Mats, Magnetic Reed Contacts, Foil Tape, PIRs and Inertia Sensors). [more]
The circuit detects a sudden shadow falling on the light-sensor and sounds the bleeper when this happens. The circuit will not respond to gradual changes in brightness to avoid false alarms. The bleeper sounds for only a short time to prevent the battery running flat. Normal lighting can be used, but the circuit will work best if a beam of light is arranged to fall on the light-sensor. Breaking this beam will then cause the bleeper to sound. The light sensor is an LDR (light-dependant resistor), this has a low resistance in bright light and a high resistance in dim light.[more]
This is a simple single-zone burglar alarm circuit. Its features include automatic Exit and Entry delays. It’s designed to be used with the usual types of normally-closed input devices such as - magnetic-reed contacts - micro switches - foil tape - and PIRs.It has an extremely small standby current - making it ideal for battery-powered operation.[more]
The Witness Camera is an automated, self-recording surveillance camera, that uses a gigabyte-class flash card as recording media.It is designed by Alberto.He design the Witnesscam because available surveillance solutions were too expensive or impractical for home use. He built the system from a VGA CMOS colour camera, a passive-infrared (PIR) movement sensor, an ATmega32 processor, and a 1GB SD-card. The prototype looks like an ordinary alarm detector. But when it detects people moving around, it silently starts recording. [more]
CodeLock is an AVR based electronic combination lock it is realised with Atmel AVR microcontroller AT90S2313 or ATtiny2313.This project used for access control. Program in hex code is 2 kB long. User code is consisted of 1 to 4 digits. If you buy the chip than user code is consisted of 1 to 8 digits. If the code is entered in the correct sequence, then after 1 second the relay and the electric striker (in the door) switch on for 1 second and then switch off again. User code can be changed via 3×4 matrix keypad.[more]
