The car alarm system is based on a Microchip microcontroller and is designed to protect vehicles against unauthorized access.
The system features two security zones - a door zone and a shock sensor zone, as well as a separate input for the hood and trunk. Its operation is organized with predefined timing intervals for arming, disarming, and alarm activation.
After arming, an exit delay allows the user to leave the vehicle while the main zones remain inactive. If a door is opened or a sensor is triggered, the system enters a warning mode and activates the alarm signal if not disarmed in time.
LED indicators provide clear visual information about the current system state - armed, delay mode, or alarm mode. The alarm output is relay-based, with selectable operating modes via a jumper.

Functions and Operating Modes
Arming delay (exit time): 15 sec.
Door zone and shock sensor zone are inactive.
Hood and trunk inputs remain active.
Disarming delay (after door opening): 8 sec.
Alarm signal duration: 45 sec.
Siren operating modes (jumper selectable):
- Mode 1: 1.5 sec ON / 0.5 sec OFF,
- Mode 2: continuous ON.

Indicators and Inputs
LED D3:
- Blinks at 2 Hz during arming delay,
- Blinks when a door is opened until disarmed or alarm activation,
- Blinks (1.5 sec ON / 0.5 sec OFF) during or after alarm activation.
LED D2:
- ON when the alarm system is armed.
Inputs:
- S1 - door switches,
- S2 - shock sensor,
- S3 - hood and trunk switches.

Technical Specifications:
Control unit: Microchip microcontroller.
Supply voltage: 12 - 14 V DC.
Alarm output: relay P1 (siren output).
Siren mode selection: jumper selectable.
Security zones:
- Doors,
- Shock sensor,
- Hood and trunk.
PCB dimensions: 62 x 51 mm.

This product is a DIY assembly kit.
It is also available as a fully assembled module - Product code 1551 (separate product).