Tecnico

DILSHAN R JAYAKODY (jayakody2000lk@gmail.com)
Colombo, Sri Lanka

In this project we design low cost high performance programmable home security system using few LDR’s as an input sensors. When above sensor(s) get triggered system may dial the user specified phone number (using build-in DTMF generator) and activate the high power audio alarm and lights. All the parameters of DTMF generator,audio alarm and light interface are programmed through the RS232 serial interface. Current firmware of this system presents interactive control system through the RS232 interface. This control system consist with the menu driven configuration options, self tests, system report generators, etc. This system also contain 5W (with 4Ω speaker) audio alarm with three selectable tone configurations, whichinclude Police siren, Fire engine siren and Ambulance siren.

SYSTEM FEATURES

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Touch tone phone dialing interface 5W High powerful audio alarm 2 sensor interface with separate sensitivity adjustments Programmed through the RS232 interface Build-In intelligent light ON/OFF switch

tone generator and µPC2002 as a speaker driver (audio amplifier). LM7805, LM7812 and LM317 voltageregulators are used to obtain +5V, +12V and +3V respectively.

Assembly
The PCB design given with this article makes the assembly much simpler. As PCB contain 230V AC main lines care must be taken while assembling the circuit. As shown in the fig.1 all the photoelectric
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Integrated Circuits
This system uses a Microchip’s PIC16F877A as a main controller, LM339 as sensor interface, UM3561 as a
All the software and firmware programs are distribute under the terms of

All the schematics, PCB designs andother documents are distribute under the terms of

RS232 Serial Interface Connector DC Power Input (18V) Program/Run switch connector

PHONE / LINE Connector

3V LASER Light Supply Line Reset switch Tone Selector Phone dialer enable switch Beeper Alarm Volume Control

Environment Sensor Connector for Sensor 1 Connector for Sensor 2

Alarm Audio Output 230V Light connector Statusindicator

Fig.1 - Connectors, Jumpers and other controls of the Programmable Home Security Alarm System

sensors, some of the switches and alarm speaker are connected with the circuit through the connector bars.

system. This button enable only when the audible alarm get activated. It is not possible to use this function at the phone dialing/ringer states. Phone dialer enable switch : Turn on thisswitch to enable the phone dialing feature of this system. Environment Sensor : In-circuit LDR to detect light conditions of the environment. Alarm Volume Control : Use this to control the output power (volume) of the audible alarm. 230V Light connector : Attach 230V AC light (or related peripheral) to these terminals. Tone Selector : Configure the master alarm tone from this jumper as follows,1—2 2—3 Open : Fire Engine Siren : Ambulance Siren : Police Siren

External connectors and controls
DC Power input : Attach DC power supply with 18V 25V (2A Max.) output. RS232 Connector : Connect RS232 serial cable to the port to configure the system. Do not use RS232 Null Modem cable with this port. PHONE/LINE connector : Attach standard RJ12/RJ11 telephone cable connector to this port. Oneport is need to use with the phone line and remaining port is for the phone (and it is optional). 3V LASER supply : 3V supply line for LASER diode assembly. Connectors for Sensor 1/2 : Attach high sensitive LDRs for these ports. To get the maximum sensitivity it is recommended to use EG&G VACTEC LDRs. Status Indicator : Indicate run, program and sensor trigger modes. Reset Switch : Press this...