AUTOMATIC RAIN ALARM SENSOR/ CONTINUITY TESTER

Rain Alarm Project is a simple but very useful project that detects Rain (Rain Water) and automatically triggers an alarm or buzzer. Water is a basic need in every one’s life. Saving water and proper usage of water is very important. Here is an easy project which will give the alarm when there is rain, so that we can make some actions for rain water harvesting and also save the rain water for using it later. With the help of saving this rain water through rain water harvesting, we can increase the levels of underground water by using underwater recharge technique. Rain water detector will detect the rain and make an alert; rain water detector is used in the irrigation field, home automation, communication, automobiles etc. Here is the simple and reliable circuit of rain water detector which can be constructed at low cost.

1. P O ND I CHERR Y UNIV E RSITY ( Po n di c h er r y Un i v er s i t y , Ch i nn a K a la pe t , Ka l a p et, P udu ch er ry - 6 5014 ) A P ROJECT REPORT ON “ AU TO MA TIC RA IN A L AR M S E N SO R / C O N TI NUI TY TE S TE R ” S u b mi tted in t h e p ar tial f ulfil m e n t o f t h e r e q ui r em e n t f o r t h e A w a r d o f Degree of M - TEC H E L ECTR O NI C S AND COM M U NIC A TIO N ENGINEER I N G S U BM ITTE D B Y FAIZAN SH A FI [2 1 3 4 1 2 ] U n d e r t he G ui d an c e of D r. K .A NU S U D HA Ass i s tant p r o f e sso r D EP A R T M E N T OF E LE C T R ONICS E NGIN EE R ING S CHOO L OF E NGIN E E RIN G A N D TE CH NOL O GY PONDICHE RR Y UNI V E RS IT Y , K A L A PET, P UDUCHERR Y - 605014

2. Ab s tr a ct R a in Al a rm Proj e c t is a simple but v e r y us e f u l proj e c t that d e t e c ts R a in (R a in W a te r ) a nd a utom a ti ca l l y tr i g g e rs a n a la r m or bu zz e r. W a t e r is a b a sic n ee d in e v e r y o n e ’ s lif e . S a ving w a ter a nd prop e r us a g e of w a t e r is v e r y import a nt. H e r e is a n ea s y p roj e c t whi c h will g ive the a la r m wh e n the r e is r a in, so that we ca n make some ac tions for r a in w a ter h a r v e s ting a nd a lso s a ve the r a in w a ter for usi n g it lat e r. W ith the h e lp of s a ving this r a in w a t e r thro u g h r a in w a ter h a rv e sti n g , we c a n incr ea se the le ve ls of und e r grou n d w a t e r b y usi n g un d e rw a ter r e c h a r g e t ec hnique. R a in w a t e r d e t e c tor will d e te c t the r a in a nd make a n a l e rt; r a in w a ter d e tector is us e d in the ir r i g a tion fi e ld, home a utom a tion, c ommunic a tion, a utomobil e s e tc. Here is the si m ple a nd r e li a b l e c i r c uit of r a in w a t e r d e t e c tor w h ich c a n be c onstru c ted a t low c ost.

3. Cont e nts 1. I N T RO D UC T I O N 1 2. C I RC U I T D ESC R I P T I ON 2 B L OCK D I A G R AM C I RC U I T D I A G R AM 3. COMPONE N T D ESC R I P T I ON 2 3 5 RE S I ST O R CAPA C I T O R TRAN S I ST O R B U Z Z ER 3.5 555 I C 3.6 5 6 7 8 9 S e nsor R a in 11 4. A D V A N T A G E S A N D D I S A D V A N T A G E S 12 5. PCB MA K I NG PR O CESS 14 6. CO N C L U S I O N A N D F U T URE SCOPE 16 RE F ERENCES 17

4. List of F igures B lock D i a gr a m Cir c uit Di a g r a m R e sistor C a p ac itor T ra nsistor B u zz e r 555 Tim e r I C R a in sensor 6.1 PCB L a y out 2 3 5 6 7 8 10 11 15

5. Chapter 1 INTR O D UCT I ON M a nkind h a s a l w a y s h ar n e ssed the e lem e nts of n a ture f o r di ff e r e nt p u rpo s e s. W a ter f o r ir r i g a tion a nd El ec tri c i t y g e n e r a t i on ( H y dro El ec t ric Pow e r ) , wind for wind mill us e d for ma n y a ppli ca tions r a n g i n g f r o m turning turbin e s t h a t g e n e r a t e e le c tri c i t y , to qu a r r y f o r c rushi n g stones, sun for d r y i n g , h ea ti n g a nd c ooki n g e sp e c ial l y wh e n bro u g ht to fo c us. F rom time immemo r ial humans us e d the sun to d r y ma n y thi n g s, a pro c e ss known a s sun d r y i n g . Sun d r y i n g is c a r r ied out in the farm, home, indust r y , l a bor a to r y , h ospitals a nd other institution for a num b e r of r e a sons. T h e se r e a sons r a nge f rom tot a l l y drivi n g out w a t e r mol ec ules f rom the thin g s b e i n g dri e d, outr i g ht d r y i n g , like c loth e s, some f a rm p r o du ce , d u ring building w o rk, a nd in s c ulpture to e x posing ce r t a in e le c t r o n ic mat e ri a ls/ c omponents dir e c t l y to the sun so th a t the ultr a - viol e t r a y s f r om the sun ca n ca u s e some c h a n g e s in the c omponent, a nd in ph a r ma c e uti ca l/ c h e mi c a l industri e s wh e r e c e rt a in plants us e d f o r p h a rm a ce uti ca l purp o s e /c h e mi ca ls a r e e x pos e d to di r ec t sunli g ht for a little while to ca use some c h e mi ca l c h a n g e s in t h e m a nd e v e n a t home sometimes wh e n we op e n o u r win d ows to a llow the sun r a y s to f a ll into our rooms t o e limin a te d a mpness, a nd a llows for proper a e r a tion. W h e n r a in f a lls, it will ca use a s e tba c k to a l l the r ea sons for su n - d r y i n g e num e r a ted a b o v e , e sp ec ial l y wh e n the mat e ri a ls b e ing sun d r ied a re not r e tri e v e d quick l y . Thus, d e si g n i n g a nd c onstru c ting a d e v i c e whi c h g ives one a h ea d s - up the inst a nt i t sta r ts to r a in hop e ful l y g ivi n g y ou time to r e tr i e ve the mat e ri a ls b e i n g sun dri e d, c lose y o u r windows, a nd bri n g in possession is not on l y a p r opos but a lso a bsolute l y imp e r a tiv e . Als o , since it ca n r a in a t a n y time without a n y w a rni n g c l o thes in a c loth e s line o u t side the house that a re a lmost d r y m a y g e t w e t i f w e do not re a li z e it is r a ining on time. 1

6. Chapter 2 CIRCUIT DIS C RIPTI O N I t is a Automatic R a in S e nsing Al a rm c i r c uit. I n this c ir c uit we use I C 555time r , 5 r e sistors, 1 ca p a c itor, 1 NPN B C5 4 5 tr a nsistor, 1 bu zz e r, 9v b a tt e r y a nd r a in s e nsor whi c h is c onn ec ted to point A a nd B a s shown i n fi g (2) 2.1 BLO C K D I A G RA M F ig 2.1: B lock D i a gr a m R a in w a ter s e nsor is t h e main c omponent in the c ir c uit. F or this r a in s e n sor, no n ee d to g o a nd b u y in the ma r k e t or onlin e . W e ca n do it ours e l v e s just b y taki n g the piece of B a k e lite or mi c a bo a rd a nd a luminum wi r e . B a k e lite or mi c a b o a rd should be made c ompl e t e l y fl a t a nd a luminum wire should be p a sted on the fl a t bo a rd a s shown in the fi g ure b e low of ra in w a ter s e nsor. C a re should be tak e n that th er e should be no sp a ce s b e tw ee n the wire a nd b o a r d. W h e n the r a in w a t e r s e nsor is c ompl e ted, it should g e t c onn e c ted to t he c i r c uit a nd volt a g e should be p a ssed thro u g h the wir e s. I f there is no r a in, the r e sista n c e b e t w e e n the wi r e s will be v e r y hi g h a nd the r e will be no c ondu c tion b e tw e e n the wir e s in the s e ns o r. If the r e is r a in, the w a t e r drops will f a ll on the r a in s e nsor wh i c h will a lso d ec re a se the r e sista n c e b e t w ee n the wir e s a n d wir e s on the s e nsor bo a rd will c ondu c t a nd t r ig g e r the N E 555 timer t hrou g h t h e tr a nsistors c i r c uit r y . On c e N E 555 is trig g e r e d,it will make the output pin hi g h a nd wh i c h will make the buz z e r to m a ke a la r m. 2

7. 2.2 CIRCUIT DIAG R AM F i g 2. 2 : C i rcu i t D i agram 3

8. I t is a v e r y simple r a in a la r m c i r c uit whi c h is d e si g n e d usi n g main l y a tr a nsistor, w a t e r s e ns o r a nd a 555 timer I C. W h e n e v e r the r e is a r a in, r a i n drops f a lls on the r a in s e nsor, a nd a s y ou ca n s e e in the diag r a m of r a in s e nsor, w a ter on r a in s e n sor would short the Point A a nd B . As soon a s Point A a nd B b ec ome s hort a positive vo l ta g e w ould g e t a ppli e d on the b a se of T ra nsistor Q1, throu g h the r e sistance R 4. B e ca use o f the volt a ge a t the b a s e , t r a nsistor b ec omes ON (initi a l l y it w a s in OFF sta t e ), a nd c ur r e nt sta r t e d fl o wing form c oll ec tor to e m i tt e r. N ow R e s e t P I N 4 of the 555 Time r , g e ts a positive volt a ge a nd 555 tim e r I C b ec omes O N a nd B u zz e r sta r ts b ee pi n g . H e re w e should note that initi a l l y the r e w a s no p ositive volt a g e a t R e s e t P I N 4 of 555 I C, a s it w a s c onn ec ted to the g r ound throu g h r e s i stance R5 (4.7 k ) a nd 555 I C on l y wo r ks wh e n R e s e t pin g e ts positive volt a g e . H e re we ca n s e e that 555 Timer I C h a s b e e n c o n fi g u r e d in Ast a ble modeso that B u zz e r g e n e r a te a os c illati n g sound ( me a ns p e riodi ca l l y on a n d o ff ). This os c illation f r e qu e n c y c a n be c ontr o ll e d b y c h a n g ing t h e v a lue of r e sistor R2 a nd/ o r c a p a c itor C1. Pin 5 c ontrol Pin, should be c onn ec ted to grou n d thr o u g h a .01uf c a p a c itor. R e sistor R3 a nd R4 h a s b ee n us e d to c ontrol the tr a nsistors c oll ec tor a nd b a se c u r r e nt r e sp ec tiv e l y . R a in s e nsor should be k e pt a t 30 - 40 d e g ree f r o m the g roun d , so that w a ter ca nnot st a y on it, for the long time, this wi l l pr e v e nt the a l a rm to g oing on f o r a lo n g time. 4

9. Chapter 3 C o m pone n t Des c ription 3.1 R E S ISTO R : A res i s t o r is a passi v e tw o - ter m i nal e l ect rical co m p one n t t h at i m pl em e n t s el e c - t rical res i s t a n ce as a c i rcu i t el em e n t . In el ec tr o ni c c i rcu i t s , res i s t o r s are u s ed t o re d u c e c urre n t flo w , a d j ust s ignal l evel s , t o div i d e vo l t ages, b i as act i ve e le m e nt s, a nd t er mi n a te t ra nsm i ss i o n lin es, am o n g o t h e r u ses . H ig h -p owe r r esi s t o r s t h at c an di ss ip at e ma n y w a t t s o f el ec t ri c al p owe r as h eat may b e u se d as p a rt o f mo t o r c o n tro l s , i n p owe r di s t r i bu t i o n sy s t ems, o r as t est l o ads f o r ge ner a t o rs. F i xe d res is - t o r s h ave res i s ta n ces t h a t o nl y c ha n ge s lig h t l y w i t h t em per a t u r e, t i me o r o p er a t ingvo l tage. Vari a bl e res i s t o r s c an b e u se d t o a d j u s t c i rcu i t el ements (s u c h as a vo l u mecon tro l o r a l a m p di mm e r), o r as se n s i n g d evices f o r h e a t , li g h t, h um i di ty, f o r c e , o r c h emi cal act iv i t y. Res i s t o rs u se d are 4.7 k , 4 7 E , 1k , F i g 3.1 : Resi st or 5

10. 3.2 CAP A CITOR A ca p ac itor is a p a ssive tw o - te r min a l e le c tri ca l c omponent that stor e s e le c tri ca le n e r g y in a n e le c tric fi e ld. The e ff ec t of a ca p a c itor is known a s ca p ac it a n ce . W hil eca p a c it a n c e e x ists b e tw ee n a n y two e le c tri c a l c ond u c tors of a c i r c uit in suffi c ient l y c lose pro x imi t y , a c a p ac itor is sp ec i fi ca l l y d e si g n e d to provide a nd e nh a n c e this effec t f o r a v a ri e t y o f pra c ti ca l a ppli c a tions b y c onsid e r a tion of si z e , sh a p e , a ndposit i oning of c lose l y sp a c e d c ondu c tors, a nd the int e rv e ning d i e le c tric mat e ri a l.A c a p ac itor w a s the r e fore histori c a l l y fi rst known a s a n e l ec tric c o n d e ns e r. F ig 3.2: C a p ac itor 6

11. 3.3 TRANSIS T OR A tr a nsistor is a s e mi c o n du c tor d e vi c e u s e d to a mpli f y o r switch e l e c tronic si g n a lsand e l ec tri c a l pow e r. I t is c ompos e d of s e mi c ondu c tor mat e ri a l usu a l l y with a tl e a st thr e e te r min a ls for c onn ec tion to a n e x te r n a l c ir c uit. A volt a ge or c urr e ntapplied to one p a ir of the t r a nsistor ’ s te r min a ls c ontrols the c u r r e nt thro u g h a n - other p a ir of te r min a ls. B e c a use t he c ontroll e d (output) pow e r c a n be h i g h e r th a n the c ontrolling (input) p ow e r, a t r a nsistor c a n a mpli f y a s i g n a l . F i g 3.3 : T r a n s i s t or 7

12. 3.4 B U ZZ ER A bu zz e r or b ee p e r is a n a udio si g n a ling d e v i ce , whi c h m a y be m e c h a ni c a l, e le c - trom e c h a ni c a l, or piezo e le c tri c . T y pi c a l us e s of bu z z e rs a nd b ee p e rs include a larmdevi ce s, time r s, a nd c o n fi rm a tion of u s e r inp u t such a s a mouse c li c k o r k e y strok e . Typ e s of bu z ze r : Elec t r o m ech a n i c a l: E a r l y d e vi c e s w e r e b a s e d on a n e l e c trom ec h a ni c a l s y stemidenti c a l to a n e le c tric b e ll without the met a l g o n g . Simil a r l y , a r e l a y m a y b ec on n ec t e d to int e r r upt its own ac tuati n g c urr e nt, ca usi n g the c ont a c ts to bu z z . O f ten these units w e re a n c hor e d to a w a ll or ce iling to use it a s a sounding bo a rd. T h e word ” bu zz er ” c omes f r om the r a sping noise that e le c trom e c h a ni c a l bu zz e rsm a d e . M ech a n i c a l : A j o y b u zz e r is a n e x a mple of a pur e l y m ec h a n i ca l bu zz e r. T h e y r e qui r e driv e rs. P iez o el e ct r ic : A pie z o e le c tric e lem e nt m a y b e driv e n b y a n o s c illating e l ec troni c c ir c uit or other a udio si g n a l sour c e , driv e n with a piezo e le c tric a udio a mpli fi e r.Sounds c ommon l y us e d to indi ca te that a button h a s b ee n pr e ssed a re a c li c k, a ring or a b e e p. B a tt e r y 9v: An e le c tric b a tt e r y is a d e vice c onsisting o f one or mo r ee le c t ro c h e m i ca l c e lls with e x te r n a l c o nn ec tions provid e d to pow e r e le c t ri c a l d e vic e s su c h a s fl a shli g hts, sma r tphones, a nd e le c tric ca r s. W h e n a b a tt e r y is supp l y i n g e le c t ric po w e r, its positive te r min a l is the c a tho d e a nd its n e g a ti v e te r min a l isthe a nod e . The te r min a l ma r k e d n e g a tive is the sour c e of e le c trons that wh e n c onn ec ted to a n e x te r n a l c ir c uit will fl ow a nd d e liv e r e n e r g y to a n e x te r n a l d e v i ce . W h e n a b a tt e r y is c onn ec ted to a n e x te r n a l c ir c uit, e le c tro l y tes a re a ble to mo v ea s ions within, a llowing the c h e mi ca l r e ac tions to be c ompl e ted a t the s e p ar a tet e rmin a ls a nd so d e l iver e n e r g y to the e x t e rn a l c ir c uit. I t is the movem e nt of thoseions within the b a tt e r y wh i c h a llows c ur r e nt to fl o w out of the b a tt e r y to p e r f orm w o rk. Hist o ri c a ll y the te r m ” b a tt e r y ” s p ec i fi ca l l y ref e r r e d to a d e vice c ompos e d o f multiple ce lls, how e v e r the us a g e h a s e volved a dditional l y to include d e vic e s c ompos e d of a sin g le c e l l . F ig 3.4: B u zz e r 8

13. 3.5: 55 5 TIMER IC: 9 P IN N AM E P UR P O S E 1 G N D G r ound r e f e r e n c e volt a g e , low lev e l (0 V ) 2 T R I G The O U T pin g o e s hi g h a nd a timing int e rv a l st a rts wh e n this input f a lls b e low 1/2 of CT R L volt a g e ( w h i c h is t y p i c a l l y 1/3 V cc , CT R L b e ing 2/3 V c c b y d e f a ult if CT R L is l e ft op e n). I n other wo r ds, O U T is h i gh a s long a s the trigg e r low. Output of the tim e r tot a l l y d e p e nds upon the a mplitude of the e x te r n a l trig g e r volt a g e a ppli e d to this pin. 3 OUT This output is driv e n to app r o x im a te l y 1.7 V b e low + Vc c , or to G N D. 4 RESET A timing int e rv a l m a y be r e s e t b y drivi n g this input to GN D , but the timing do e s not b e g in a g a in until RESET r ises a bove a ppro x im a te l y 0.7 volts. Ov e r r ides T R I G whi c h o v e r r ides th r e shold. 5 CT R L Provid e s “c ontrol” a c c e s s to the int e rn a l voltage divid e r ( b y d e f a ult, 2/3 V cc ). 6 T H R The timing ( O UT h i g h ) int e rv a l ends w h e n the volt a g e a t thr e shold is g r ea ter than t h a t at CT R L (2/3 Vc c if CT R L is op e n). 7 D I S Op e n c oll ec tor output w h ich m a y disc h a r ge a ca p a c itor b e tw e e n int e r v a ls. I n p h a se with output. 8 V c c Positive supp l y volt a g e , whi c h is usu a l l y b e t w ee n 3 a nd 15 V d e p e ndi n g on the v a ri a tion.

14. F ig 3.5: 555 Tim e r IC 10

15. 3.6 RAIN S E NSOR: A r a in s e nsor or r a in switch is a switching d e vice ac tiv a ted b y r a in f a l l. Th e re a re two main a ppli ca tions for r a in s e n s ors. The fi rst is a w a t e r c ons e rv a tion d e vi c e c on n ec ted to a n a utom a t i c ir r igation s y stem that c a us e s the s y stem to shut down in the e v e nt o f r a inf a ll. The s e c ond is a d e vice us e d to prot e c t t h e int e rior of a n a utomob i le f r om r a in a nd to support the a utom a tic mode of winds c r e e n wi p e rs. An a dditional a ppli ca tion in pro f e ssion a l s a tellite c ommunic a tions a ntenn a s is to trigg e r a rain blow e r on the a p e rtu r e of the a nten n a fe e d, to r e move w a t e r dropl e ts f r om the m y l a r c o v e r th a t k ee ps p r e ssuri z e d a nd d r y a ir inside the w a v e - g u ides. R a in s e nsors f o r ir r igation s y stems a r e a v a il a ble in both wir e less a nd h a r d - wi r e d v e rs i ons, most e mpl o y i n g h y gro s c opic disks that s w e ll in the pr e s e n c e of r a in a nds shrink b a c k d o wn a g a in a s th e y d r y out a n e l ec tr i ca l switch is in turn d e pr e ssed or r e le a s e d b y the h y g r os c opic di s k sta c k, a nd the r a te of d r y i n g is t y pi c a l l y a dju s ted b y c ontrolli n g the v e ntilation r e ac hi n g the sta c k. Ho we v e r, some e le c tri c a l t y p e s e ns o rs a r e a lso ma r k e ted that u s e tipping bu c k e t o r c ond u c tan c e t y p e pro b e s to me a sure r a inf a ll. W ir e l e ss a nd wir e d v e rsions both use simil a r me c h a nisms to tempo ra ri l y suspend w a te r i n g b y t h e ir r i g a tion c ontroll e r s p ec i fi ca l l y th e y a re c o n n ec ted to the i r r i g a tion c ontroll er’ s s e nsor te r m i n a ls, or a re inst a ll e d in s e ri e s with the solenoid v a lve c ommon c ir c uit su c h that th e y p r e v e nt the op e ni n g of a n y v a lves wh e n r a in has b ee n s e ns e d . 11

16. F i g 3.6: R a in S e n s or Chapter 4 Advanta g es and Dis a dvanta g es ADVAN T A GES: Cons er ve Wate r : T h e re is a lot of w a t e r t h a t y ou c a n s a v e b y u s ing a r a in s e nsor. B y a utom a ti ca l l y t u rning o ff y o ur l a wn ir r i g a tion s y s t e m e v e r y time it r a ins, the c ons e rv e d w a ter ca n be us e d in oth e r e s s e nti a l purpos e s such a s fi ghting fi r e . P r e v e nt Dis e ase D am age and Nut r ient: L oss Ov e r- w a te r i n g p r e v e nt t h e roots of y our plants f r om r e a c hing d ee p into the g round maki n g y our plants vulne r a ble to dise a s e . Ov e r - w a t e ri n g is a lso one of the major c a us e s of nutri e nt loss in plants a s e x ce ssive w a t e ring w a sh e s a w a y the nutri e nts of the soil le a ving y our p l a nts w ea k a nd unh ea lt h y . Save M on e y on F e r t iliz e r : A r a in s e nsor p re v e nts y ou f rom ov e rw a t e ring y o u r plants a nd la w n. W h e n a plant is ov e r w a t e r e d, the nutri e n ts f r om the turf w a sh a w a y into the dr a in a ge s y stem. You h a ve to c ompens a te b y a ddi n g mo r e f e rtili z e rs to y our la w n a nd plants. This me a ns sp e nding mo r e mon e y on f e rtili z e rs. W ith a r a in s e nsor that eff e c tiv e ly p r e v e nts y our la w n ir r igation s y stem f r om ov e r w a te r i n g y our la w n a nd plants, y o u r g a rd e n t u rf will r e main to be a n ide a l envi r onment f or y o ur pl a nts in acc or d a n c e w ith the f e rtili z e r th a t y ou a re usi n g . In cre ase the Li fe - span of your I rr igation System Usi n g a r a in s e nsor pr e v e nts un n ece s s a r y w e a r a nd te a r o f y our l a wn ir r igation s y stem si n c e it minim i z e s the a mount of time that y o u r la w n ir r igation is in op e r a tion. This is e sp ec ia ll y us e ful duri n g the r a in y s e a son wh e r e r a in unpr e dict a b l y c ome a nd g o. P r e v e nt G r ound w a t e r and Wat e r w ays P ollution A la w n ir r i g a tion s y stem e quipped with a r a in s e nsor minimi z e s w a ste f ul run off su c h a s p e sti c ides, motor oil, f e rtili z e r, p e t w a ste a nd s e dim e nts f r om r e ac hi n g y our w a t e r w a y s. I t a lso minim i z e s g a rd e n pollutants su c h a s h e rbi c id e s a nd f e rtili z e rs f rom g e tt i ng into y our g roun d w a ter s y stem. 12

17. DISAD V ANT A GES: I t does n ’ t t e ll a bout the sp ee d of t h e r a in which is f a ll e n on the r oof. I t will send s i g n a l or t he led w ill be g lowing u n til the d e te c tor b e c o m e s w e t. I t som e thi n g is ov e r t h a t th e n the d e te c t o r w ill not wo r k until it g e ts w e t. Th e re a re so m a n y p r o blems that y ou will fa c e wh e n y ou will make this c ir c uit. 13

18. Chapter 5 PC B MA KI N G P RO C ESS W hile d e si g ning a l a y o u t, it must be noted that the si z e of bo a rd should be a s small a s possible B e f o re st a rtin g , a ll c o mponents should be pla c e d pro p e r l y so that a n a c c ur a t e me a sur e ment of s p a c e c a n be mad e . The c omponent should not be mount e d v e r y c lose to eac h other or f a r a w a y f r om one a nothe r . The l a y out is fi rst p r int e d on tr a c i n g p a p e r th e n tra ce d on c op p e r pl a te. The c opp e r pl a te is fi rst dip in photo r e sistive solu t ion. Th e n it is he a ted a nd d r y . Th e n pla c i n g print on c o pp e r pl a te a nd t h a t pl a te on ultra li g ht e x posure b ox for 15 min. Th e n plate is dipp e d in thinner wh e r e the t r a c ks g e t visibl e . Th e n this pl a te is k e pt in e tching solution f o r 15 m in. Th e n drilling is done a c c ording to the c ompo n e nt s . 14

19. F ig 6.1: PCB L a y o ut 15

20. Chapter 6 C O NC L U SION A ND FU T UR ES C O P E C O N CLUS I O N The r a in w a ter d e te c to r - a la r m s y stem will be u s e f ul in both domestic a nd industri a l a ppli ca tions. I t a le r ts the us e rs of the p r e s e n c e of r a in wh e n it is just a bout to r a in as e v e n the minut e st droplets of w a t e r tr i g g e rs it ON the r e b y g ivi n g t h e us e r a m ple time to r e t ri e ve pos s e ssions, shut windows, a nd in some ca s e s pr e p a r e to h a rv e st r a in w a t e r. T he d e vice wh e n p rop e r l y pla c e d to r e c e ive the fi rst s e t of dropl e ts of rain w a ter ca n s a v e the us e r f r om d a m a g i n g poss e ssions that w e re b e ing sundri e d/pr e v e nt r a in f r o m ent e ring ho m e s, offi c e s, a nd silos et c . FUTURE SC O P E Using more a ppro p ri a te r a in s e nsor we ca n m a ke pr e c ise a utom a tic r a in s e n s ing s y stem b y a dding mi c r o c ontroll e r - b a s e d s y stem we ca n implem e nt some s ec uri t y f ea t ur e s for f a rme r . 16

21. R E FRE NCES h t t p s: // c ir c u i t d i g e s t .com h t tp s : // c ompon e n t s 1 1 . c om E m be d d r on ic s . h ttp // www .e m be d d r o n i c s .com 17