PIC CONTROLLED INTRUDER ALARM

Transcription

1 Constructionl Project PIC CONTROLLED INTRUDER ALARM JOHN BECKER A sophisticted multi-zone intruder detection system tht offers deluxe monitoring fcilities. W HEN Editor Mie suggested tht the uthor might be interested in designing PIC controlled intruder lrm, the suggestion ws ccepted in the nowledge tht to do the job properly would me worthwhile chllenge. The uthor hs designed lrms before but none hving the sophistiction tht ppered possible through using PIC microcontroller. It seemed tht n idel system should hve the fetures itemised in Pnel. It is believed tht ll the requirements listed in the Pnel hve been met in this design. How they re implemented will be discussed s we progress. CONCEPTUAL LOGIC Designing n intruder lrm system is bsed on the simple Boolen logic concept tht sensor s switch contcts cn be either open or closed. If the contcts re found to be in the opposite condition to tht in which they should be (e.g. open when they should be closed), then n lrm condition exists nd pproprite ction should be ten. Prototype PIC Controlled Intruder Alrm showing control bord, min function selecting eypd nd l.c.d. disply, but excluding entry sensors nd lrm sounders etc. Everything else follows on from this logicl rgument but, s is illustrted through Pnel, there re mny fctors tht me considerble difference between -gte circuit tht simply detects n open-closed condition nd system tht provides gret mny other security iding fcilities s well (there re round 00 progrm commnds in the controlling softwre for this design). CIRCUIT DIAGRAM The min circuit digrm for the PIC Controlled Intruder Alrm is shown in Fig.. The principl functions re s follows: Min Zones PICF microcontroller IC is in chrge of the entire system. Vi port pins RD0-RD nd RC0-RC, which re used in input mode, the PIC cn monitor between one nd eight sensor zones, plus n extr Pnic zone vi RB. The quntity is selected by the user nd cn be chnged t ny time. Zone detection will be discussed shortly. Alrm Outputs Four udio/visul lrm control outputs re provided, three vi pins RE0-RE, nd one vi RB. When ctivted, these pins go high nd re specificlly intended for driving n internl buzzer (RE0), externl strobe (RE), externl bell (RE) nd ny device of the user s choice (RB). As will be discussed in reltion to Fig., the outputs cn ctivte these devices (depending on their type) either directly, or vi power trnsistors TR to TR. In ny lrm condition, the bell, strobe (if fitted) nd buzzer re ll ctivted. The bell remins ctive for period preset (nd utomticlly stored) by the user through the softwre, with mximum durtion of 0 minutes. The softwre prevents the bell from restrting gin, irrespective of further unuthorised zone entries (but see Pnic Switches lter). Once ctivted, the lrm system cn (normlly lso see lter) only be reset by eying in the correct PIN code. Disply A liquid crystl disply (l.c.d.) module, X, is controlled vi pins RA0-RA operted in output mode. Pin RA is n opencollector output nd is bised high to the V power line vi resistor R. The l.c.d. displys vriety of messges in respect of the severl control nd sttus modes tht cn be selected vi the pushbutton eypd(s). It is used in conventionl -bit control mode nd its contrst is djustble vi preset VR. Keypd(s) The min control of the system is ccessed vi stndrd -ey lphnumeric dt entry eypd, S, through which unique -digit lphnumeric personl identity (PIN) code hs to be eyed. There re 0 permuttions ( ). The sttus of the eypd s pushbutton eys is monitored vi port pins RC-RC used in output mode, nd RB0-RB used in input mode. Port B s internl light pullups re ctivted in the softwre nd dditionl bising resistors for RB0-RB re not needed. Fcilities for the use of n optionl second -ey eypd, S, re provided, for resons discussed lter. Four of its pins shre pins RC-RC with eypd S. The others re monitored by pins RD-RD used in input mode, with logic-high bising provided by resistors R to R. 0 Everydy Prcticl Electronics, April 00

2 PANEL : PIC Controlled Intruder Alrm Fetures B Monitors between one nd eight entry/exit points (zones) of building or room B Allows monitoring to be totlly or prtilly suspended when required by the legitimte gurdins (users) of the premises B Indictes udibly (e.g. bell) nd/or visibly (e.g. strobe) when one or more zones hve been entered without uthority B Turns off ctivted bell fter preset period to prevent nnoynce to neighbours B Allows timed zone entry/exit (time-out) for users without triggering the full lrm B Allows full monitoring of required zones once time-out hs ended B Allows users to terminte time-out procedure B Allows users to control the monitoring system by mens of unique lphnumeric personl identity code (PIN) entered vi eypd B Allows users to chnge the PIN code B Allows users to ccess the control system without using PIN code in the event of system filure or servicing B Normlly powered from mins power source B Instntneously switches over to being powered by hevy duty bc-up bttery if mins power fils B Keeps the bttery fully chrged when mins power is present (the bttery should be cpble of eeping the monitoring system nd ny ctivted lrms opertionl for resonble period) B Allows the system to resume ctive monitoring should power totlly fil but subsequently resume B Indictes tht there hs been totl power filure even fter power hs been resumed B Prevents the bell from being ctivted when power is resumed B Indictes for lter viewing whether zones hve been entered, even though there my lso hve been power filure nd resumption B Allows monitoring of fewer zones thn re vilble B Automticlly recognises whether sensor should be monitored for n open circuit or closed circuit B Allows open circuit or closed circuit sensors to be used without system modifiction B Recognises tht sensor is incorrectly open or closed prior to monitoring being ctivted nd indictes which sensor is incorrect (i.e. door open when it should be closed) B Allows users to preview zone sensor sttus B Allows the bell-on time to be set for shorter period thn the 0 minutes permitted in the UK B Prevents the bell-on time exceeding the UK limit B Allows users to chec the system by mens of indictor lights without ctivting the bell (etc.) B Allows indictor lights to disply the sttus of the power supply nd bell (etc.) B Provides nti-tmper wrning of interference with the system B Provides Pnic button tht immeditely ctivtes the bell (etc.) even if the system is not set for full zone monitoring B Provides pssive dvice (e.g. buzzer) tht zone hs been entered even if the system is not set for full monitoring, nd for the dvice to be terminted once the zone hs been vcted (e.g. to monitor shop-door opening/closing) B Accepts ll conventionl types of switched-output commercil sensor, including mgnetic ctches, pressure pds, pssive infr-red (PIR) devices, vibrtion detectors, etc., nd for ny mixture of these to be used B Provides n optionl slve eypd with seprte PIN for dditionl ccess to selected zone B Inherently stble nd most unliely to be triggered except vi the instlled sensors B Inexpensive to construct V VE D0 D D 0 D D X D L.C.D. D MODULE D RS E CX R/W D N R GND INT. BUZZER EXT. STROBE EXT. BELL NC NC NC *TB NC D D D D RS E R/W VR 0 R 0 R TO R 0 VE VE RA0/AN0 PSP0/RD0 RA/AN 0 PSP/RD RA/AN/VREF PSP/RD RA/AN/VREF PSP/RD RA/TOCK TOSO/TCKI/RC0 RA/AN/SS TOSI/CCP/RC CCP/RC SCK/SCL/RC PSP/RD PSP/RD PSP/RD 0 RE0/AN/RD PSP/RD RE/AN/WR SDI/SDA/RC 0 RE/AN/CS SDO/RC TX/CK/RC CONTRAST RX/DT/RC C 0p X.MHz C 0p INT/RB0 RB OSC/CLKIN RB PGM/RB IC PICF-P RB RB PGCLK/RB OSC/CLKOUT 0 PGDA/RB MCLR GND GND S x MATRIX S x MATRIX RM R TO R 00 UNALLOCATED OUTPUT UNDER S CONTROL * ALARM ZONES TO RM TO D/D S ENGINEER TB S PANIC VPP DATA CLK PROGRAMMER * Fig.. Min control unit for the PIC Controlled Intruder Alrm. Everydy Prcticl Electronics, April 00

3 Immedite Pnic Port pin RB cn be used s n lterntive to using one of the eight min zones for Pnic switch monitoring. The pin is used in input mode (internl pull-up ctivted) nd when Pnic switch S is pressed to short this pin to the line, n interrupt is generted in the PIC nd flg is set. In response to this flg, the softwre triggers the full lrm system, bell, strobe nd buzzer (see Unuthorised Entry lter). This occurs whether or not the rest of the lrm is in ctive or pssive mode. The flg is then reset. The bell-on time is subject to the norml bell-on time-out, but lso see lter. Timing The PIC is operted t MHz, s set by crystl X. It is this rte which determines the ccurcy of the softwre cloc tht controls the bell-on durtion nd entry/exit timing. In order to comply with the llocted timings, different frequency must not be used with this design. The voltge t the D/bttery junction is fed vi diode D to provide pproximtely V d.c. to power externl sensor nd lrm wrning devices, up to totl current of bout 00mA (llowing resonble hedroom for bttery chrging currents nd tht required by the control bord). Fuses FS nd FS prevent trnsformer overlod nd bttery dischrging in the event of short circuit between the V nd lines. It is recommended tht pnel mounting fuseholders re used. The voltge t the D/D junction is regulted down to V by IC. This provides power for the PIC microcontroller IC nd l.c.d. X, neither of which must be powered t higher voltge. The presence of n output voltge from IC is displyed by l.e.d. D. ALARM DEVICES As previously sid, there re four outputs through which the PIC cn ctivte externl lrm devices, either directly or indirectly, depending on their type. Fig.. Ech trnsistor is cpble of sining A sourced from the V d.c. power line, but remember tht this line cn only supply bout 00mA, s sid erlier. Becuse of the wy in which the softwre is written, externl udio/visul lrm devices should only be connected in the order shown. The buzzer is frequently used to indicte vriety of functions, such s eypd presses, to indicte tht entry/exit timing is in progress, nd tht n entry hs been mde if the pssive mode is in opertion. The buzzer is lso ctivted, long with the strobe nd bell, in the event of n unuthorised intrusion being detected when the system is in full monitoring mode. The bell is utomticlly turned off fter preset dely vi line RE nd trnsistor TR. The strobe nd buzzer, though, remin ctive until n uthorised user resets the lrm. The uxiliry output option controlled vi line RB is only ctivted for the mximum period tht hs been set for it, more lter. PIC Progrmming During development, the uthor progrmmed the PIC vi his Toolit TK system (Oct/Nov 0) nd terminl bloc TB. Resistor R nd diode D llow correct opertion of the MCLR pin during nd fter progrmming. This fcility my be used by those who wish to progrm their own PIC in situ. Preprogrmmed PICs re vilble s stted lter. POWER SUPPLY The design is intended to be mins powered with bttery bc-up. Referring to Fig., mins trnsformer T provides V.c. secondry output t bout A. This is rectified by REC nd smoothed by cpcitors C nd C. Light emitting diode (l.e.d.) D, buffered by resistor R, provides poweron indiction when voltge of bout V d.c. is present cross C. A mins input fuse is not used but could be included if preferred. The rw d.c. voltge is fed to regultor IC whose nominl V d.c. output cn be djusted upwrds by preset VR. The intention is to set IC s output voltge to the level tht best suits the chrging of the externl V bc-up bttery, typiclly bout V. Current t the required voltge is fed to the bc-up bttery vi diode D, which prevents the bttery from dischrging bc into IC during mins power filure. L A.C. MAINS INPUT N E V FS A - REC W00 C 00µ C 00n R D IN The PIC is cpble of supply ma from ech output pin, but it hs mximum totl output current cpbility of 00mA (which must not be exceeded). The ma current is cpble of directly driving wrning buzzer, of the type tht hs its own in-built oscilltor. It could lso trigger lrm devices such s bells or strobes tht hve their own control circuit built in to them. Most externl devices, though, re liely to require driving t voltges nd currents greter thn the PIC cn supply. For this reson, ech of the RE0-RE/RB outputs re connected to power-drlington trnsistors, TR to TR, s illustrted in IC COM VR D N00 OUT C 00n FS A IN TO BACKUP BATTERY Fig.. Power supply circuit digrm. Fig.. Circuit digrm for lrm output device drivers. D N00 IC 0 COM OUT D R 0Ω C 00n V V In ddition to controlling their respective trnsistors (if instlled), the four output lines ech hve n l.e.d./resistor pir. The l.e.d.s re turned on whenever the respective PIC line is high, regrdless of whether trnsistor is lso connected to tht output. Ech trnsistor hs diode connected between its collector nd the V line. This is to inhibit bc-e.m.f. pulses in the event tht n inductive lod is being driven vi the trnsistor. It is permissible to control solenoids or relys. INTRUSION DEFINITIONS Returning to zone intrusion sensing vi pins RD0-RD nd RC0-RC, refer to Fig.. This shows the equivlent circuits for the zone components when used with sensors tht re normlly-open or normlly-closed. To clrify possible source of confusion, the following definitions re used in this text: Normlly-open mens ny sensor which when in its norml required ctive stte when monitoring n entry/exit point hs its contcts in n open condition (see Fig.). Devices tht wor in this context of normlly-open include pressure pds which require, for exmple, someone to tred on them in order to trigger the lrm system. Normlly-closed mens ny sensor which when in its norml required ctive stte when monitoring n entry/exit point hs its contcts in closed condition (see Fig.b). Everydy Prcticl Electronics, April 00

4 Devices tht wor in this context of normlly-closed include mgneticllyoperted switches secured either side of two djcent sections on door nd its frme. The proximity of the mgnet when the door is closed eeps the switch contcts closed. When the door is opened, the contcts open nd so the lrm is triggered. When ordering components for your lrm system it is importnt to understnd these descriptions in reltion to this design. Such terms hve been nown to crete considerble confusion in the pst. Hence our defining them now! ZONE CIRCUIT LOGIC In Fig., sensors re inserted into resistor networs s shown. In Fig., with the sensor in normlly-open condition, the voltge t the junction of the 00 nd resistors is, nd monitored s such by the PIC. 00 V A TO PIC INPUT If zone is intruded, the sensor s contcts close nd the voltge cross the component series becomes the voltge t the output of diode D, bout 0 V below thtpresent t the bttery, nominlly V. The voltge ctully fed to the PIC is tht set by the potentil divider vlues nd will vry depending on the voltge cross the divider. Providing the input voltge is bove 0 V DD (V 0. = V), the PIC will recognise it s logic. The bttery voltge cn probbly drop to s low s nd the PIC should still receive n input voltge recognisble s logic. In Fig.b, with the sensor in normlly-closed condition, the voltge t the junction of the 00 nd resistors is recognisble s logic (see previous prgrph). If zone is intruded, the sensor s contcts open nd the voltge fed to the PIC flls to. The resistor in the chin protects the V power line in the event of the sensor s cble being cut nd shorted to. It ws felt to be unresonble to ttempt to protect the system ginst very high voltges being mliciously pplied cross sensor cbles. Severl sensors my be used in ech zone. For normlly-open zone they must 00 V B TO PIC INPUT A NORMALLY OPEN WHEN IN USE ALARM TRIGGERED WHEN CONTACTS CLOSE E.G. DOOR ENTRY PRESSURE PAD B NORMALLY CLOSED WHEN IN USE ALARM TRIGGERED WHEN CONTACTS OPEN E.G. MAGNETICALLY CLOSED REED SWITCH be wired in prllel (Fig.c). For normlly-closed zone they must be wired in series (Fig.d). Do not mix normlly-open nd normlly-closed sensors in the sme zone. C NORMALLY OPEN SENSORS ARE WIRED IN PARALLEL D NORMALLY CLOSED SENSORS ARE WIRED IN SERIES Fig.. Zone intrusion sensor logic options. KEYPADS The first of the eypds, S, is for eyed control of the totl lrm system, including responding to unique PIN code when eyed-in, rejecting ny code tht is not recognised. Fcilities for second optionl eypd, S, hve been included following reder s request. During development of this lrm system, Dvid Myntt of Mnchc, Texs, emiled us to sy tht he wished to instl system tht would llow his (presumbly responsible) children to let themselves into the house by use of coded eypd or similr technique, nd could we help. After weighing up the vrious pros nd cons, it ws decided to include second eypd with this controller which would be lrgely independent of the min system, but which would llow PIN code to be eyed in nd ctivte line RB nd Drlington trnsistor TR. As sid erlier, the trnsistor cn drive lod such s rely or solenoid, consequently it could be used to ctivte n utomtic door-ltch, such s the type used in response to intercom requests t office or prtment premises, for exmple. The PIN code required for eypd S is initilly set vi eypd S s prt of the min system. In opertion though, eying the correct PIN into S directly ctivtes TR. A countdown is strted t tht instnt nd TR remins on for period which cn be previously set s required vi the min system. During this time the buzzer on line RE0/TR is lso ctivted. At the end of the preset period, the buzzer nd TR re turned off gin. This secondry control is not tied into the min zone sensing system. If the secondry entry time-out period is not met, for exmple, the min lrm system is not triggered. However, secondry entry could be mde to tie in with the min system s well, by treting this entry zone s n lrm zone with its own seprte sensor. This would require, therefore, Dvid Myntt s children to enter their own PIN on eypd S (instlled in porch outside the min entry door, for exmple). This could cuse the min ltch to open, but once the door itself were open, would ctivte the countdown timing of the min system s uthorised entry mode. The children would thus need to use the household s min PIN to dectivte the lrm within its llocted entry time. It would be permissible, but perhps unwise from security point of view, to give the sme PIN code to both eypds. PANIC SWITCHES As referred erlier, two options for Pnic switches hve been included. The first cn be mde using Zone, which is never llowed to be turned off through the softwre. A normlly-open or normllyclosed pushbutton switch cn be used, mounted t strtegic loction. When the switch is pressed, chnging the sttus of its contcts, n lrm condition is sensed nd the full bell, strobe, buzzer system is ctivted, s with other zones, with the bell still subject to time-out nd non-retriggering. The other option is vi pin RB. This is normlly held high vi its internl pull-up resistor. When normlly-open pushswitch S is pressed, the pin is shorted to. Agin n lrm condition is sensed nd cted upon. In this mode the bell is still subject to the preset time-out period, but cn be rectivted if the Pnic button is pressed gin. It seems resonble tht if someone relly is in Pnic sitution tht they should be llowed to rectivte the bell t will. Unlie the first option, this Pnic mode is triggered whether or not the min lrm is in monitoring mode. The condition once triggered needs to be reset in the usul wy. Be wre, however, tht this interruptdriven option is potentilly we lin in the system s stbility. All other lrm zone monitoring is done vi softwre polling of the zones. Interrupts vi RB, though, re utomticlly generted by the PIC in response to ny -going chnge of logic sttus t this pin. Wheres it is believed tht the power supply nd other zones re liely to be lrgely immune to externl electricl interference (such s cused by electricl storms), n RB interrupt might conceivbly be triggered under such conditions. Reder feedbc on this would be welcomed. If this Pnic interrupt is not required, connect lin between the pins of the S connector, so holding RB permnently low. CONSTRUCTION This design is mins powered nd its construction should only be underten by those who re suitbly experienced or supervised. Printed circuit bord component nd trc lyout detils re shown in Fig.. This bord is vilble from the EPE PCB Service, code. Assemble the components in order of size nd use socet for the PIC. Do not insert the PIC, or connect the l.c.d., until the correctness of the power supply hs been confirmed. It is not necessry to instl ll the zone terminls shown. Just solder in those tht re ctully required. The system cn be configured lter in softwre (vi eypd S) to suit the entry zones you ve decided to use. Nor do you hve to instl ll output controlling trnsistors if their higher power cpbility or control functions re not needed (e.g. omission of the strobe or second eypd fcility) similrly with their terminl connectors. Note tht the output Everydy Prcticl Electronics, April 00

5 AUX BUZZER STROBE BELL BATTERY D D D D D D D D0 D D D R D OUT IC R0 e c TR b R R e c TR b R R e c TR b R R e c TR b R R OUT COM IN IC C VR COM IN VR R RM RM C C C TB C D D D D RS E VE CX X R R R R R R R R R 0 D IC R R R R REC C S TB S S MCLR DATA RB CLK RB V A.C. S PANIC ZONES. 0IN (0. mm). IN (. mm) Fig.. Printed circuit bord component lyout nd full-size trc mster pttern. Everydy Prcticl Electronics, April 00

6 control logic is inverted if the trnsistors re not used. If the buzzer is to be used, TR must be instlled. The l.e.d.s nd their bllst resistors cn lso be omitted s you see fit, lthough they do offer useful monitoring fcility if you need to troubleshoot the circuit t ny time. Whilst it is not necessry to fit lin wires between unrequired zone terminl/trc pirs, it is preferble to retin ll zone bissing vi resistor module RM. This will help to provide electricl stbility to the PIC s unused inputs. If Pnic mode detection vi RB is not needed, wire this pin to the line to eep it stble. It is suggested tht the eypd(s) should be connected vi ribbon cble nd suitble -pin connectors to mtch their terminl pins nd those on the bord. A rer view of the eypd pinouts is shown in Fig.. REAR VIEW A COMPONENTS Approx. Cost Guidnce Only excluding cse nd lrm hrdwre 0 B C D Resistors R, R, ( off) R to R, R to R0 ( off) R to R 00 ( off) R, R to R0 0W ( off) See SHOP TALK pge RM x common -pin s.i.l. resistor module RM x common -pin s.i.l. resistor module (R to R 0 W % crbon film or better) Potentiometers VR 0 min. preset, round VR min. preset, round Cpcitors C, C 0p cermic, mm pitch ( off) C 00m rdil elect, V C to C 00n cermic, mm pitch ( off) Semiconductors D, D to D N signl diode ( off) D, D, D0 to D red l.e.d. ( off) (see text) D, D N00 rectifier diode ( off) REC W00 A bridge rectifier TR to TR TIP0 npn Drlington trnsistor ( off) (see text) IC PICF microcontroller, pre-progrmmed (see text) IC V A voltge regultor IC 0 V A voltge regultor Miscellneous S, S -ey ( x ) dt entry eypd ( off, see text) S push-to-me Pnic switch, extr lrge, plmctivted, wll-mounting S push-to-me switch, p.c.b. mounting, 0 in pitch FS, FS A fuse, slow-blow, with pnel mounting holder ( off) T mins trnsformer, V secondry, A rting or higher TB 0-wy pin-heder strip, TB X X 0 in pitch, mm di. -wy pin-heder strip, 0 in pitch, mm di. (see text) MHz crystl -line -chrcter (per line) lphnumeric l.c.d. module Printed circuit bord, vilble from the EPE PCB Service, code ; 0-pin d.i.l. socet; -wy terminl blocs, p.c.b. mounting, side-by-side stcing, 0 in pitch, screw connections (quntity to suit ppliction, see text); metl or plstic cse to suit ppliction; V hevy-duty seled led-cid bc-up bttery; ribbon cble (- wy) for eypd(s) (see text); -pin pinheder strips nd connectors, 0 in pitch, mm di. (-off, optionl, see text); p.c.b. supports ( off); connecting wire; solder, etc. Alrm fittings Intruder sensors, bell, strobe, buzzer, types s required to suit ppliction, -wy or -wy lrm cble (see text) PIN - CONNECT TO Fig.. Rer view of eypd connections, plus eypd legends. It is recognised tht if the second eypd is lso used, the cost of running -wy ribbon cble from the unit cross severl metres to door could be considerble. An lterntive is to use two lengths of stndrd -wy lrm system cble to me the connections for pins to. Pin is simply for grounding the eypd s metl frme to erth nd cn possibly be ignored (but consider ny possible mins electricl sfety spects first ny metl item tht could potentilly come into undesirble electricl contct with mins supply must be erthed). It would lso be resonble to use just four connections so tht only four eys re ctive. The sme degree of code security would remin since ll eys would still pper to be vilble. TESTING To ssist bench testing, temporrily connect one or more switches to vrious zones to simulte sensors. Fully chec your p.c.b. ssembly for errors nd poor soldering before pplying power. Do not connect mins power to the system until you hve checed the rest of the system using V bttery (or bench power supply). Connect the bttery to the llocted terminls nd chec tht V is present t the output of regultor IC, nd tht round V is present t the cthode () of Everydy Prcticl Electronics, April 00

7 diode D (i.e. bout 0 V below the bttery s ctul output voltge). L.E.D. D should be on. If ll is well, disconnect the bttery. Connect the secondry winding of trnsformer T to the terminls provided. Set preset VR for minimum resistnce between the common pin of regultor IC nd the line. Ensuring stisfctory sfety precutions re observed, connect mins power to the trnsformer. There should bout V d.c. cross the terminls of cpcitor C nd V t the output of IC. Adjust VR until voltge of bout.v (or the rechrging voltge specified by the bcup bttery mnufcturer) is present cross the bttery terminl bloc pins. Disconnect the mins power, insert the PIC, nd reconnect the bttery (which should be in resonbly fully-chrged stte when first put into use). If the PIC hs not been progrmmed yet, you cn do this in situ now, using Toolit M or M vi connector TB. POWERING UP When powering up with the progrmmed PIC in plce, your first need is to djust the l.c.d. s screen contrst using preset VR. Ignore ny informtion which then becomes pprent it depends on the existing contents of the PIC s dt EEPROM. Hving set the contrst, put the progrm into Engineer s Mode by holding down eypd D (bottom right), then pressing nd relesing Reset switch S (mounted seprtely on the p.c.b.), nd then relesing ey D. This ction llows n uthorised engineer (i.e. you!) to chnge the min PIN code without previously nowing the correct one. On other occsions, it lso resets the lrm if it hs been ctivted, turning off the bell, etc. Additionlly, it resets vrious defult fctors: Zones to be monitored nd Entry/exit zone Entry/exit time 0 seconds Bell-on time minutes Keypd entry time-out 0 seconds Normlly, the PIN code nd other fctors cn be mended from within the running system, but only fter the correct PIN hs been eyed in. On entry to Engineer s mode, you will be greeted by the -line messge: Enter your chosen -chrcter PIN code using ny of eys 0 to nd A to C, for exmple: A. The other three eys (bln, deciml point nd D cnnot be used for the PIN code. Ech eypress is ccompnied by beep of the buzzer nd its ssocited l.e.d. being briefly turned on. Ech ccepted eypress digit will be shown on line. If you me miste, press the bln ey to cler line, llowing you to strt gin. Pressing bln when no digits re shown exits this mode. When ll four digits hve been entered, press D. The word STORED will now pper briefly, telling you tht the code hs been stored in the PIC s dt EEPROM for future recll. All dt EEPROM vlues re retined even fter power hs been disconnected. The screen then displys ALL OFF on line, with line cler. From here on, ccess to ll modes must be prefixed by your PIN code being eyed in. Key it in now. If you enter wrong digit, nothing will hppen. There is no screen confirmtion of which ey is pressed, for obvious security resons. When the correct PIN hs been entered, line displys the messge SELECT MODE. You now hve choice of eleven modes, selected by pressing one of the following eys: 0 Activte lrm nd strt exit-dely count-down Chnge min PIN code Chnge entry/exit time (time-out) Set zone to be regrded s the sole min entry/exit point Set zones required to be monitored when the lrm is ctive Set bell-on time, between nd 0 minutes Automticlly ssess zones for sensor sttus (normlly-open or normlly-closed) Disply norml zone logic (sensors n.o. or n.c.) for informtion only Select second PIN code, s required for second (optionl) eypd Set entry time for zone covered by second eypd B (deciml point) Set pssive mode in which ny zone entry is displyed nd buzzer sounded, terminted when zone entry ceses When new dt hs been eyed-in, press D to store it in the dt EEPROM, confirmed by STORED ppering nd return to SELECT MODE. All modes except Pssive (see lter) my be exited by pressing the bln ey, but ny chnged dt is NOT stored if you do so. Hving escped from mode, or hving completed ny chnges permitted by it nd stored them by pressing D, the screen returns to displying SELECT MODE, nd nother mode selection cn be mde. Pressing the bln ey when SELECT MODE is shown, fully exits the mode selection fcility, followed by ALL OFF gin being displyed. It is necessry to ey-in your min PIN code (eypd ) to re-enter the mode selection fcility. Next time dt mode is entered the dt displyed is tht previously eyed in nd stored. Ech mode will now be discussed in detil. MODE 0 ctivte lrm system When Mode 0 is entered, the softwre first checs tht ll zones hve the open or closed sttus s set in Mode (ssess zone logic). If they do not, -line messge is displyed, of which the following is n exmple: in which zone is not in the required condition (e.g. door open when it should be closed). The llocted entry/exit zone my remin open t this time, since tht is the route tht will be ten by the user once the lrm hs been set on. This messge will continue to be displyed until the zone hs been returned to its required condition, or the bln ey pressed to exit this mode nd return to disply of ALL OFF. If the bln ey is not used, when the incorrect zone sttus hs been remedied, the lrm-on procedure will resume, nd -line messge shown, such s: where the countdown strts t the seconds vlue previously set for the entry/exit dely nd proceeds to count down to zero. The buzzer sounds during this period. The countdown my be terminted nd return mde to ALL OFF if the bln ey is pressed. Otherwise when zero is reched the system will be plced into the full lrm monitoring condition, wtching those zones set through Mode : An exit from nd closure of the llocted entry/exit zone must be mde within the llotted entry/exit time. Filure to do so will cuse n lrm condition to exist. MODE Chnge min PIN code Discussed previously. MODE Chnge entry/exit time On selection of Mode, the screen displys -line messge such s: where the vlue following PREV is the previously set time-out period in seconds. Everydy Prcticl Electronics, April 00

8 Any vlue between 0 nd my be selected (note the prefix 0 for vlues below 0). Ech digit entered is displyed t the bottom left of line. If you me miste, press the bln ey to cler the vlue just entered, llowing you to strt gin. Note tht you re returned to the SELECT MODE disply if bln is pressed when only one digit hs been entered. If more thn two digits re eyed in succession, the others will be ignored. MODE select entry/exit zone On entry to Mode, -line messge will be displyed, such s: where in this instnce the numerl indictes tht Zone is currently the selected entry/exit zone. As MAX sttes, one of six zones cn be nominted s the entry/exit zone. Pressing ny ey between nd selects tht zone nd the chosen digit ppers, replcing the pproprite dsh, nd with dsh now replcing the previous digit. Zones nd cnnot be selected for entry/exit s these re regrded by the softwre s being for nti-tmper nd Pnic zone use. MODE select zones to be monitored On entry to Mode, -line messge will be displyed of which the following is n exmple: B When in Mode (set entry/exit zone) the selected zone utomticlly cuses the sme Wtch zone to be ctivted. MODE Set bell-on time On entry to Mode, -line messge will be displyed of which the following is n exmple: Through this mode you cn set the time for which the bell is turned on if unuthorised entry to zone occurs. There is legl limit in the UK of 0 minutes mximum. You my set time between nd 0 minutes. In the bove exmple, the previously set bell-on time is shown s minutes, with the MAX0 reminding tht 0 minutes is the mximum. On line,?? is where your newly selected time is displyed when you press the permitted numeric eys. The first digit (the tens of minutes) cn only hve vlue between 0 nd. A vlue between 0 nd cn be eyed for digit (the units ). The following conditions pply, though: If digit hs vlue of, only 0 cn be entered for digit. If digit hs vlue of 0, vlue of 0 cnnot be eyed in for digit. This ensures tht only time between nd 0 minutes cn be selected. MODE Auto zone ssess On entry to Mode, -line messge will be displyed of which the following is n exmple: MODE View norml zone logic On entry to Mode, -line messge will be displyed of which the following is n exmple: This mode is for informtion only. It simply shows the normlly-open nd normlly-closed logic for ech sensor s stored in the dt EEPROM in this cse they re ll shown s normlly-open. MODE Set second eypd PIN On entry to Mode, the following line messge will be displyed (but with line bln): Mode is used in the sme wy s Mode, but llowing you to enter the required - digit PIN for use with the optionl eypd. It my be the sme PIN s used with eypd, but it does not provide ccess to the min system. Note tht if you hve chosen to use just -wire connection to eypd (s discussed erlier) you cn only use those eys for which wiring exists. All others will be ignored. MODE Set eypd entry time On entry to Mode, -line messge will be displyed of which the following is n exmple (fter the new entry time, secs, hs been eyed-in): This exmple shows tht zones nd hve been selected for unuthorised ccess monitoring. If ny of these zones re entered when zone monitoring is ctive, n lrm condition will exist, ccompnied by the bell nd buzzer sounding, nd the strobe flshing (if instlled). The exception is when the zone entered is tht llocted s the entry/exit zone. If this zone is entered during ctive monitoring, the entry/exit countdown timer will strt, with the buzzer sounding. If the correct PIN code is eyed-in within the llotted time (see Mode ) the system will be dectivted nd the buzzer silenced. If the entry/exit dely is exceeded, then the bell nd strobe will be ctivted. When in Mode, pressing ny ey between nd will toggle tht zone between ctive (wtched) nd ignored. When selected, the zone number will be displyed, otherwise dsh will be shown). Note the following, however: B Zone cnnot be deselected s the softwre regrds this s being Pnic zone. B Zone, nominlly llocted s n ntitmper zone, cn be selected/deselected. B Any zone nominted s the entry/exit zone cnnot be deselected. This mode llows the system to ssess whether it should be monitoring individul zones s normlly-open or normllyclosed. The letter C in ny of the eight positions on line indictes tht zone sensor is currently closed, letter o shows tht it is currently open. In this exmple, zones, nd re shown s hving normlly-closed logic. Zones,,, nd hve normlly-open logic. The settings shown in line cn be stored to the dt EEPROM by pressing D, they will then be the settings tht the system checs re correct when in ctive monitoring mode. Should ny sensor be found to be in different condition, nd tht zone is one of those selected to be monitored (see Mode ), then n lrm condition exists. The system then behves s described under Mode (bells etc.). Before pressing D to store the dt, physiclly visit ll zones nd ensure tht the sensors re in the required condition, i.e. doors nd windows closed, the ct not sitting on the pressure mt, wife not moving round in front of the PIR sensor, etc. Except for bln, ll other eys re ignored in this mode. This mode sets the time during which the uxiliry output (trnsistor TR) nd the buzzer re ctivted when the correct PIN code hs been eyed-in vi eypd. At the end of the time-out, TR nd the buzzer re turned off. This mode is used identiclly to Mode. MODE B Activte pssive monitor mode An eleventh mode is vilble, entered by pressing the B (deciml point) ey. On entry to this mode, -line messge will be displyed of which the following is n exmple: When in this mode, ll zones re monitored nd if ny re found to hve their Everydy Prcticl Electronics, April 00

9 sensors in the opposite logic to tht expected (e.g. open insted of closed), the buzzer sounds until ll sensors return to their norml expected sttus. The pproprite zone numbers re displyed on line, with the number being replced by dsh when no longer triggered. In the exmple, zone hs been entered. This fcility cn be used, for exmple, in shop when it desirble to now if customer hs opened door, or removed n object from where it should be. Pssive monitoring is terminted by eying in the PIN code, to return to SELECT MODE. MODE SUMMARY The following is the summry of the modes nd their eyed identities. It is suggested tht you photocopy it nd secure the detils to the front pnel of your enclosed lrm. 0. Set lrm on. Set min PIN code. Set ccess time-out. Set ccess zone. Set ctive zones. Set bell time. Set zone logic. Show zone logic. Set nd PIN code. Set nd time-out B Set pssive mode CHOICE OF SENSORS It is believed tht this design cn be used with ny type of intruder sensor currently vilble. The choice is entirely yours s to which type you use for which zone. Mny compnies sell intruder lrm products nd they or their ctlogues should be consulted for dvice on the sensors vilble. The choice of cse nd bc-up bttery is lso yours. For the ltter seled ledcid type rted t V nd, sy Ah, is suggested. If you re using the nti-tmper option, it recommended tht microswitch is instlled in the cse nd the bell housing, cusing n lrm condition if either enclosure is entered without uthority. The system cn be used to monitor just one zone. Ech zone used cn be connected by using -core cble (vilble specificlly for lrm use). If nti-tmper detection is required, -core lrm cble should be used, the entry sensor itself wired to one pir, the nti-tmper connections mde by the other nd connected seprtely to the system s llotted nti-tmper terminls (zone ). Anti-tmper wiring could be connected in series between ll required zones. Alterntively the zones could be treted s seprte nti-tmper connections, with ech cble pir commoned into the zone terminl bloc. The ltter technique my me it esier to trce n open-circuit should one occur. Anti-tmper wiring should lwys be normllyclosed. It is debtble s to whether nti-tmper monitoring is required in norml domestic security system. UNAUTHORISED ENTRY If one more zones re entered without uthority, the bell, strobe nd buzzer re ll ctivted. A cloc is strted from zero when the first zone is entered. The screen chnges to disply messge showing which zone hs been triggered, plus the cloc red-out, e.g.: In this exmple, zone is shown to hve been entered nd tht it is hour, minutes nd seconds since tht event. The cloc continues counting until the lrm is reset vi your PIN code. The elpsed time cn rech :: (just over four dys long wee-end, for exmple) nd then restrts from zero. The bell is utomticlly turned off fter the preset dely period hs elpsed, s discussed erlier. The strobe nd buzzer remin on until reset by eying in your PIN code. If second unuthorised entry is mde following the first, the bell is not rectivted, nor does this event ffect the cloc s current counting. It is the elpsed time since the first entry occurred tht continues to be shown. The disply, though, is updted to show the number of the second zone (or more) s well s the first. When Pnic mode is triggered vi switch S, the cloc is lwys reset to zero. If the bell time-out hs not completed following zone triggering nd totl power filure occurs, the bell is NOT rectivted when power is resumed, lthough the buzzer nd strobe re re-triggered. When entering the correct PIN code to stop n lrm condition nd turn off the bell, strobe nd buzzer s pproprite, ll zone nd timing informtion remins on screen until bln is pressed to cuse return to ALL OFF mode. Be ssured tht even if the lrm is in ctive monitoring mode nd use of the eypd is mde, full system scnning continues, preventing unuthorised users from fooling the system by holding down ey indefinitely. TOTAL POWER LOSS If there is totl power loss through mins filure nd lc of bttery power, nd then one or the other is restored, the softwre restrts from Reset condition. In doing so, it notes this fct nd displys one of three messges. If the system hs not been set into ctive monitoring mode, the following -line messge ppers: The second line is clered when you enter your PIN code nd enter SELECT MODE, from which you cn immeditely escpe if you wish (press bln ey). If the lrm ws previously in monitoring mode nd there hs been no unuthorised zone entry, -line messge similr to following is shown: This indictes tht no zones hve been intruded nd tht it is seconds (nd counting!) since the power ws restored. If one or more zones hve been intruded, the messge might pper s: indicting tht zone hs been entered nd tht pnic hs been pressed, gin showing the elpsed time since power restortion. The messge PSU ERR (or the erlier POWER ERROR) mens tht you should chec the condition of your bttery. To cler either of the lst two messges, you must reset the lrm by eying in your PIN code nd pressing bln to return to ALL OFF. AUTHOR S EXIT The PIC Monitored Intruder Alrm hs not been tested in ctive service. However, it hs been extensively bench tested with vriety of switches nd sensor-simultion devices. It is believed tht it lives up the specifictions outlined erlier, but this cnnot be gurnteed nd no legl responsibility cn be ccepted for it. However, if you hve ny suggestions for how the system could be improved, plese dvise us t Editoril HQ (not vi the Cht Zone since we do not visit this regulrly). My you live without intrusion! RESOURCES Softwre for this design is vilble on -inch dis (for which nominl hndling chrge pplies). It is lso vilble for free downlod from out ftp site. (See PCB Service pge.) Red this month s Shoptl pge for dditionl detils on obtining the softwre, plus pre-progrmmed PICs, nd generl informtion on buying components for this PIC Controlled Intruder Alrm. Everydy Prcticl Electronics, April 00