Microcontroller-Based PC Thermometer with Regulated Fan
Contents
1. Do PWM movf PWM Count W subwf Fan W E btfss STATUS C F goto PWM_OFF bsf 2 goto Inc PWM PWM OFF bef 2 Inc PWM Count F movlw D 16 subwf PWM Count W btfss STATUS C goto Do_PWMX clrf Count Do PWMX return 1 Disp Data LCD RAM Buf addlw D 8 movwf FSR bsf FSR 7 swapf Temp Curr W andlw H 0F addlw 30 movwf INDF 2 incf FSR F movf Temp Curr W andlw H 0F addlw H 30 VARIABLE USED movwf INDF Wait1 Val Wait2 Val F movf Fan W Msg Num movwf Temp2 F 1 call BIN2BCD 2 movlw LCD RAM Buf Temp3 Temp4 F D 24 d movwf FSR LCD DPort bsf FSR 7 Ten W LCD_CPort PORTD LCD EN equ 7 addlw d LCD RS equ 6 movwf INDF incf FSR F LCD Line Max equ 7 movf Unit W F LCD Char Max equ D 16 andlw addlw H 30 LCD 11 Addr equ D 00 80 movwf INDF H 80 Disp DataX return LCD L2 Addr equ LCD L1 Addr D 40 82. Set 50 LCD Subroutine bcf LCD CPortLCD RS 1 endm 1 Set RS1 macro bsf LCD RS endm Pulse bsf LCD CPort LCD EN nop bcf LCD CPort LCD EN call Waiti F return Init LCD set RS to 0 Set 50 movlw D 200 load 10mS delay call Wait2 movlw D 200 load 10mS delay call Wait2 movlw H 38 set LCD to 8 Bit Data 2 line display movwf LCD DPort F call Pulse movlw D 100 load 5mS delay call Wait2 call Pulse movlw D 100 5mS delay call Wait2 call Pulse movlw D 100 load 5mS delay call Wait2 1 movlw 06 set Display Increment No Shift movwf LCD DPort call Pulse EN movlw set Disp ON Cursor ON movlw set Disp ON Cursor OFF Blink OFF movwf LCD_DPort call Pulse EN F movlw H 14 set CursorMove Shift to Right movwf LCD DPort call Pulse movlw H 01 Clear LCD Display mo
3. Get Temp movwf Temp2 movf HLW movf ADCO_LO W movwf bef STATUS C rf rf 2 movf Temp2 W movwf Temp BIN call BIN2BCD movf Ten W swapf Ten W iorwf Unit W movwf Temp Curr Get_TempX return 1 DeciLp BIN2BCD Unit drf Ten clrf Hundred Deci00Lp movlw 0 100 subwf Temp2 W btfss STATUS C goto Dec10Lp 2 lt 100 movwf 2 2 gt 100 incf goto Dec100Lp Dec10Lp movlw D 10 subwf Temp2 W btfss STATUS C goto DeciLp movwf Temp2 incf Ten F D 10 goto Dec10Lp movwf Unit return Temp2 W I Get Fan clrf Fan movlw D 25 subwf Temp BIN W btfss STATUS C goto Get Fan movwf Fan Get Fan A STATUS C mf D 15 subwf Fan W btfss STATUS C goto Get FanX D 15 movwf Fan Get FanX return
4. 2 A wyo AST As S3NI I Z X 39H3 AX IdSIG 021 gt Z 3 List of Materials Material Quantity PIC16F877 LM35 LCD 2X16 8 MHz Crystal Oscillator VNP35 104 Multilayer Capacitor 105 Multilayer Capacitor V4 watt resistor 1000 microfarad 16v electrolytic capacitor 22picofarad ceramic capacitor Blower Fan Heat Sink 2 pins Terminal Block 8 pins Connector 10k array resistor N 5 P Table 3 1 List of Materials The essential components of the design are the thermal sensor microcontroller and the cooling fan The thermal sensor which is the LM35 Sensor Figure 3 4 directly measures the temperature inside the computer The LM35 series are precision integrated circuit temperature sensors whose output voltage is linearly proportional to the Celsius Centigrade temperature Other materials used in the project are shown in Table 3 1 With the different temperatures measured the microcontroller which is PIC16F877 Figure 3 5 performs various functions the sets or regulates the speed of the cooling fan The obtained temperatures and the fan speed are displayed using the LCD panel A microcontroller or Programmable Interface Controller PIC is a functional computer system on a chip In addition to the usual arithmetic and logic ele
5. 1 org 0 0000 start of reset vector goto Initialize org 0 0004 start of interrupt service routine goto ISR routine 1 Initialization Routine Initialize TMRO Clear TMRO clrf INTCON Disable Interrupts and clear TOIF bcf STATUSRPi bsf STATUS RPO Select Bank 1 movlw B 11000100 prescaler of 1 32 movwf OPTION REG movlw B 00001110 Set ANO as Analog input movwf ADCON1 B 11011111 0 1 IN movwf TRISA Port 11 movlw B 00000000 0 00 1 IN movwf TRISB Port movlw B 00000000 0 1 IN movwf TRISC Port C xxxx schmitt movlw B 00000000 0 00 1 IN movwf TRISD Port D xxxx xxxx schmitt movlw B 00000000 0 00 1 IN movwf TRISE Port E ooocschmitt bcf STATUS RPO Select Bank 0 call Init Var I call Init ADC call Init LCD call Disp LCD bsf INTCON TOIE Enable TMRO
6. st dl ard E1575 aer tel b gt Temparahi a Pow 13 3220098 caliiratiba the wafer love Tc LMA low pul imped ac ies 06 01 D33282 te 15 van be used wilh poe applies cr villi pus zd virus As AT nA ae sA css tum 1 in s ai M35 gt nied to spares mar a fo 1529 mape eile bee Rabo is rate 3 407 Ip 12 177 will sccurasyl The Sore B Connection Diagrams Can Package 92 Plaetic Package 10 22 ma packages vol dles tho LUSSO 042524 VES ere sesilab a ir Plastic 111 712 packeqe 13530 19 2132 e in a b Ead mulak small aula sslic 222 psc aze Features m 11 7 iin 100 iri C suse ixc zr m OFC AX rasy pare 2 m AMM doc mitt ie nc ranger m Suilubl far appicalimas m Sut waler level Iian ity m Opaies 7 1037 vo15 m ces 20 cual dan W ve elio DI
7. 205 SART Cam gt RT POR GIR ORT nk 187 zh A 123 d Ed 1 1 12 Zams ARON Tors MSSP USART MSSP VAS USART zharwels 5 ir zu 5 Siru lari els 52 nebuclurs 25 isa oiris 52 25 ir sli cionis 01 Technol Ine nE307327 335 3 PIC16F87X 10 DEVICE OVERVIEW Tais seven cunis dee ue Addilisis rey ss feud n be Yid zarga Ma wal stick mas ostanes Tay your local Mizrecdh Zaez ateg 07 cowTicackdl Mizrechis vetste eer Varas souls ze 2 conprierieri Any lo U e 42 4 ard ie mazing for better inneren rg e the devine arzFitezturc ard aceratio ef t ar per masuka FIGLIRE 1 1 T Program FLASH Dala MEFS 122 2 92 355 12 3 Counce F 11 281 Prog am Anny Ht rez unit ILLA OULU CTT Hula 1 ghee AM al rw 01 loro Ine EEPROM 175 255 Bytes aw oar oas SCARF SCARTATA PEI ERBE ard 1915 5721 covered sheet devices come pn pazkalen an 21216 5 7 874 devices core on 4Cc pn pa
8. Current 10 mA Nolu 2 Slerayc TO 6 Packayy 60 Clu 1 18090 M35 s5 Cio 1180 C Package BE Ee Wee 14350 1 35 YU lo 11 SO B BSC lu 150 C 353 0 C10 1100 C 20 150 C vad Temp TO 6 Package Srldering 10 secrnds 300 02 Packayy Sulduriny 10 sccunds 260 C Package Soldering 10 seconds 2302 Electrical Characteristics 1 Note 6 LM35A LM35CA Design Tested Design Unils Typical Limit Max Note 5 Molte 4 Note 5 Accuracy Ta 2h 6 2 10 C 05 10 Ta Tax 04 Tain 0 15 C Nunlinvarily Trin Tras 20 35 0 13 0 3 IC 5 Senser Gain 110 0 9 9 mv G Avoraqu 10 1 Load Regulation Ta 286 x 11 0 94 11 0 mv Note 3 21 0 5 _ 3 0 10 5 mV m line Regulation Ta 256 0 4 10 05 10 01 l my v Mate 3 z 10 02 0 1 0 02 my hy Quiescent Current FHC i pA Nate Ver 5 114 80V i 30 118 p Chanye vi ys IOV 250 pA Curren V 2 0 pA Nulo 3 Turnpurale ru 0 5 0 39 0 5 MAC Coctticicn Quiescent Current Mininu m Temperature In circuit of 1 2 0 gt 0 tar Dated Acnurany
9. pags F AUT 1 Ina PIC16F87X TABLE 1 1 PIG 16F87T3 PINOUT DESCRIPTION Enc Ian BuHar PIn Description Pint Fint Typa x QET KU EIH Qadab tya 6 cek s eysa bo crystal oc ranabe 11 payal RU mide ar 242305 ach F23 H d 1301 and deames Ihe insirazbon cycle rcs Pasion pa or pris ot begs inp Tals Pin 15 5 se ser lew In ar POR SIS bh ant HE HA alsz Em rpc EA 514 Ee Face RAF can slat Fr cw rpi72 o wee daye HMIe 2152 Em 333123 laren j 1 5 alsz Ire rpetzzzam mal oper dal 2 RAS cun be inp ze deve suc rr chrzaous seal 2 8 FOR Bsab drecbor2 S par FOR 2car be praga tar LUZ on sll rp rs 114511 alsz Fe sabe mal pin FEI TL 15 3 IL cun be ilo oo U CW inpul Ili rmpt on 335 pl lier ipio ead gu pii F SART 7 Dil
10. iib ers pecz arr eich se vz spon W A Yez nalock irast gt ANN ns irestri cti 1 f lt 74 wards gt FI NSH Pegan Mamers Lip to 232 Soles o Lats Merere RAWI Upto 5 23 85 x EzI xCIM Jata Prost zomsxibe te the Inber ap capabi by c 14 Col lees des sonus Died ins il ad els riz modes Pese ur Revel 7074 Power up T IPART ard ator Star ap OST Wate idag Tins vea cnc p RU ator for r7 inble anna 212 sade praeterit cn Posen SI FF Selects gsc stor ost cs Low soe high sseel CMOS 7 Fu stats Ina curt log srarurg IRI pris Save SV r Ssi cece lily dri 2 vail Sebi gy ty vis byu piis te access th PERAN rrr Wida voltage rz 7 fv t Sw High Te 23 Connie Irdicrizl z 1d 2z77nzcd 7 naraha ranges Low power Uma 0 2v 4 v z JUS wpol g 32 Hz v 1 La current Pin Diagram F ww QW Cf Eee oe Lu paeem 2 6 2 tL 27242227 aC sC n I i b
11. sr ar II chek T uz berapi ya bps Gaal dacs sjenr input P O 35ker T rps AT F w nF 7T oper Nora 4 Rial etei xe Aas ar nel bem 2 This bole is Serai Tigga trl sd seed Uni bates a Ingaer 21 wt cme 25 01572 purges anp a her Q rad n 25 Slave voce ni rinieriscrazz x ogrzzessor 345 4 This por ban wf Z es rd COS rper hier OV s DECRE pags AOIN Bel na la Techralegy Ina APPENDIX LM35 Data Sheet t ioni Semicornmduciur Senomber 1534 LM 35 LM35A LM35C LM35CA LM35D Precision Centigrade Temperature Sensors General Description I ASE gara ars precision nmiagraraz zisim 1 merear Ime zulpul vo lays is riqa ural to fra Galal i2 ferpeara ina the IRSA tus 168 ar adwaabage irear Ie purir bate ia Advi a9 ond tued lo 85001186 9 1928 201 aisge mm 5 cz obama ceneseriear Cirih sea ng 25 dees mel sis estin cai bratoa 1 te peor de 72123
12. ADC Reg 0 13 Hundred equ ADC Reg D 14 1 Init ADC 10 clrf Curr01 clrf Count movlw B 00000001 i 00 001 movwf ADCONO select ANO to convert clrf ADC Sel clrf DataH cif DataL clrf HI gt clrf LO return Read ADC incf ADC_Dly F movlw D 30 subwf ADC_Dly W btfsc STATUS C movf DIy W sublw D O btfss STATUS Z goto Read ADCX movf ADRESH W get A D result movwf ADC DataH save to ADC Data ADRESH movwf FSR bsf FSR 7 movf INDF W movwf ADC DataL movlw B 00000001 movwf ADCONO ensure A D is active movf ADC DataH W movwf ADCO HI movf ADC DataL W movwf ADCO LO movlw B 00000001 00xx x001 movwf ADCONO select AN1 to convert call Get Temp call Get Fan ADC Sel Read ADCX movf ADC DIy W sublw D 25 btfsc STATUS Z bsf 2 start A D conversion return
13. t y long Tem Stability T47 for 0 08 16 08 E 1000 hat rs Note 1 Unessobieraiss Old sies seu i ins tpi s 5220272 1 STC Iur HOS ead 14255 Ale Tye TC m LAC UAC zd YT I OFS Gr Jis LHSSD V5 52 pA nois sess bol yee Z These spos ue uns eles lo ZC s Tues n ci orca ol WBpendaisdens 4 boldtece cers the om ranan Note 2 Terria rysy aaz 2 ds 23 2204004 liin lo eign end 222260 nzlon Io Tisrnal of llo 7 552 pastaya TAY 15 4 DT 15 vaace ed nieder 5 22 062 06 ah eni s st dae 1 719 p nag 2 iarra 0 emala En add ena choral soar Minna on ser wa 2 1 dan eppleadens sadlen Electrical Characteristics Note 1 Note 6 Conlinuzd LM35 LM35C LM35D Tested Design Tested Design Units P ramat r Limit Typlest Limit Max 4 Nole 5 Note 4 Nole 5 Accuracy Ta 250 0 10 04 10 s LM25 154350 102 0 5 05 2215 Nulo 7 Ta Tmax 10 8 08 15 Ta Thain LOUK 0 8 9 0 Accuracy T4 25G MGB Ta Thanx _2 0 Nate Nonlinearity 6 5 Nete Hj Senser Gain Trai Ta rz Tg 9 8 nee Sepu 10 2 Lead lalion 1 266 Nulc 31 0 Lgi mA Trin
14. Actus us Temperature E i 5 Tr m m IF EimridJp Huspinumn s 5 E 3 rr kE D a 1ni 565uu nx ex ETE Hurra gt gt Applications he zar be auplizr warily ir z3z same wey as 1 fepe Ira se vere IF cen ra veniens 3 ud os wil gs within DOI ab ite arko am pelar bis prestan ess thal artisi cir p xps amparadura IT ite lr tenpe ghne ers mish pue oc bennperz ares bz 1719 491 3 9 1 9 329 ard bemperabucs Cs is dm cee viz TO 2sckega were copper asss e prn pal pak sary Feat int che sz temuera rg closer 72 Ira 1o ma 3i uu Ferrera ri riririza Wis prihen 26 sura ire by iba MGS ex iL eaves devise is al 712 wta nb Pe dn cn FIS 15 suver wres amp bess z whisk dl aab be aie am all at ibe same wpera Arts J US LSS cies il nat ke a7zcted tas
15. vinum OF Prost 1411 1471 11 33 3511 ELLE Q z 0028 TY US 1 780 1 I BUI TIL MP LEU HM 3 us 1311329 a LOE 1 Power Package 202 Ora r Nurnhar LMSS5OP NS Package Number Centigrade Temperature Sensors LM35 LM35A LM35C LM35CA LM35D ision Prec Physical Dimensions rere wilrazterz a mar 25 d o deg SEA PK 77 Diei 299 5 5 p 072 245 LTD Em 1 49 2 145 0 055 11 4 20 222 0 32 4 ou E 2 13 MI Meta Yr 7 TO 52 Pacino 2 Order Number LMSSCZ LM35CAZ LMSSDZ NS Pockoge Number Z034 SUPPORT POLICY PHCLLCISS NOL FOR Let b CE ZOWPOMES 5 IF Lik SIPE CaS D4 IHz EX 2EL 3 Wel D IFz 24 Ub RA IONAL SEN CONLUCIUOH COE CE HG 1569 1 Fifa Javie gle am a 7 Ola GG ay GQ yamg which ae gupy cal Jevis ARI into eas sinn lile sue does Q Laudem sue dfe 0
16. 77 1024 Ry Siv tym SC lg 221 n T 147 4 Howe 8 be dC y K oba Mos 121 p ck ol ee u u ar Roin Typical Applications Hess LOO TEMO cit Pe qu FIGURE LMz5 with Decoupling from Capacitive Load CAPACITIVE LOADS Like kep arza s the HS bes a eb lily TAPAS AAS 121 Wey wet rn 53 pf will oul Gave ane it zz 1855 21 Sia AE ie lu N capacitance wit a series R ranpe om m gon 4 enir taz Utat is a3plizz 3 retir shown Ir Ap 5 E of 1119 Preis r 115490 LOAD 13 ETC ai sume l Cet av ATS Teed iY FIGURE d LM25 with R C Damper cpa ite espactarex arns ypas Iran 2 pal oulpal dewe as ail ius coarezted in wires n 3 Fasti e its peor nare aa amp lercaz Irrarze atm sources sul as 19 radio Irsisindl sro Ata arn Erisbes GR eza et 93 Hs wiring sar a 35 xgezsutirg srg ile ir ju jO 15 veri act rzchhzrs 0 benz r
17. 3 0 10 51 Me gt C LA LECUT nc AS D 12 Fea CAAT FIC1BFS77 n FIC1BF874 RzXAH52D FATA HH comin gt H HZ RI a REG LI HA nA ww LLLE RESAHAA r 14 TT x 1 ET gt PIG18F877 18 4 T LA 7 23 Cz m OLS 25 a 556209 3DXPSF U 4 44 21 3D1F3F1 Techrobogy ine RD PST Man PIC16F87X Key PIC micra Mid Range Reference Manual 0232221 eqe uy RISITS ene Ds aysi FLASI 414 Darz terrors betes Gate nary 1 20 Perts Caphara pars Path vedi es Serial Correr 15 Pare lel 10 bl gt Digis Yed Fil ad ur Sel PIC16F873 16 874 1 PIC1EF977 EC 20111 22 2 EC 323 5
18. Figure 4 1 Testing Prototype with Multimeter Table 4 1 Test of DC Fan without Device Temperature Voltage DC Current A Power kW N A 12 0 00042 5 04E 06 In Table 4 1 Test of DC Fan without Device as shown above the data were obtained after testing the DC fan without the device using a multimeter The results showed that the voltage current and power measured is constant since the DC fan is used without the device Table 4 2 Test of DC Fan with Device Temperature Fan speed Voltage DC Power kW 559 Above 15 11 2 0 000004256 539 549 14 10 5 0 000003675 51 C 52 C 13 9 9 0 000003168 499 50 C 12 9 3 0 00000279 47 C 48 11 8 5 0 00000238 459 46 10 7 9 0 000001975 43 44 9 7 1 0 000001562 41 42 8 6 5 0 0000013 399 409 7 5 9 0 000001003 37 38 6 5 1 0 000000765 35 36 5 42 0 000000504 33 34 4 3 4 0 00000034 31 32 3 2 6 0 000000182 29 30 2 2 1 0 000000105 27 28 1 1 45 4 35 08 26 Below 0 0 81 0 The results after testing the DC fan with the device with the multimeter are shown in Table 4 2 Test of DC Fan with Device From the data obtained the fan speed was proven that it varies as voltage is increasing or decreasing Also from the data table shown above power being consumed by the device also varies when t
19. 2265247 5 15 15 877 874 enol 21 ae nU db 1 8 1 119 4 9 c 8074 Peripheral Features iO 8 bl sil 5 bil 15 zil orbi e rar be nzr2 nentzd dur 19 FFP a csterral ork Ine 2 bt tire err Shit 20702 register prescale 512 postecs er VM les Capture s bt ezoljter 12 rs Corpore Iz 15 21 rek reeclutioa ors rax ur 12 bil 13 bil rlt Analog lu 2 gibsl zu e len Syrenururs SSP vil SP 2 rane ard IC Linim mal Syrcarorcus sgrcbrarcis Rez vcr Transmitter USAR TSC wti S b dress ER e e l aalel Slave 2 et exleiral RD ane CS ocnlis 4024 erly Giese cul Dicari cul Gesell 0211 Microcup 1 Inc paqs PIC16F87X Pin Diagrams PDIP SOIC MS Radies iine KIN Fea 201 RI 17 CK Imm 1 FIC1G6FB87G B73 a oO 3ESTCN qn XX e SCTRUDT arp wa A HT an 264 E 2077 pags Rn OA 0
20. Moreover John Guy in his article entitled Circuit Provides Efficient Fan Speed Control March 4 2004 made study similar to our design which is circuit that provides efficient fan speed control John Guy created a circuit that has the same objective of our design He implemented his logic to control fan speed by using a thermistor as a temperature monitor The thermistor produces voltage that is proportional to the temperature The circuit as shown in Figure 2 4 uses a thermistor gave the researchers a possible alternative as a temperature sensor The circuit included multiple power outlets that allowed multiple fans to be connected This study gave the group possible improvements that can be implemented on the design 1 1 2 28 167 PAR BEND pF OSOON L 073216 180 pF gt BEAD 1 228 Ol pF uH MBRS190 1 01 ii 4 8 12 7 27k 5 1 15k D Ra 10k BEAD 01 pF 43 SALUMINUM AE NTC 2 L evetroune To control fan speed thermistor RT adjusts the output voltage of this converter Figure 2 4 Thermistor Based Fan Control Circuit Additionally an article written by Ken Gay 2007 entitled Understanding Closed Loop Fan Speed Control showed two types of fan speed control variation which are the Closed Loop Variation and Open Loop Variation His article mostly discussed closed loop variation
21. dood in 8220293023 saele zi 3 2251 ile Ier cee 11219 dabei ct t ies Le Uo iiis injarv deve gt Whew bare 4484 de Mess do inm Meum os Ix Gri Aiz ui 43 nir kw hie DER wc ve st Cie amp 14 dr dados gt wati naa hotel 4 4 4 lof o 4 get T ZA AD ied dein n lt p X s one APPENDIX D Installation Manual Installation Manual Microcontroller Based PC Thermometer with Regulated Fan 1 Select an available drive bay of the computer where the device can be mounted 2 Place the device to the available drive bay of the computer Make sure the locks the side of the device would fit on the drive bay to ensure that the device is placed correctly Make sure the casing of the computer can accommodate an extra cooling fan usually side panel of the casing If not the casing of the computer must be modified Install the cooling fan which is connected to the device to the casing of the computer Pla
22. what are its benefits and 20 advantages This gave the group the knowledge that there were two types of variation The group also learned that closed loop variation uses a tachometer in order to adjust its speed In Mr Darrin Vallis article entitled Closed Loop Fan Control at System Level 2004 he discussed briefly the disadvantages of an open loop and how closed loop can be better in comparison This article gave the group a wider knowledge on the advantages of a closed loop The article also discussed that a tachometer feedback is used in a closed loop variation Mr Vallis also discussed in his article what tachometer feedback is and how it works In addition Myke Predro 1997 in his book entitled Handbook of Microcontrollers discussed Motor Control and LCD Control The article discussed the different methods that can be used to control motors The article discussed that the easiest way to control motors is to switch them on and off This study was used by the group since the project involved is controlling the fan speed depending on the temperature The article suggested that controlling the motor speed is normally done by pulsing the control signals in the form of a pulse wave modulated signal which is usually called Pulse Width Modulation The group used the knowledge gained from the article about pulse width modulation and other methods on controlling motors in the design of the project Also the article on LCD con
23. TMRO Interrupt Service Routine I TMROint bcf INTCON TOIF Reset TMRO Overflow Flag movlw D 06 Store value to TMRO addwf TMRO F call Read ADC Do PWM call Disp Data call Disp LCD TMROintX goto RestoreReg done Restore registers amp exit Msg0 addwf PCL F 0123456789012345 dt Temp _ degC dt Fan __ x Init Var clf Msg Num Ld Msg2RAM clrf Temp Curr clrf Temp BIN clrf PORTA clrf PORTE clrf PORTC PORTD return Variable Declaration ADCO HI equ ADC Reg ADCO LO equ ADC Reg 1 ADC_Reg 4 ADC Data equ ADC_Reg 5 Data equ ADC Reg 6 ABUS equ ADC Reg 7 Curr10 equ ADC Reg 9 Curr01 equ ADC Reg D 10 Coumt equ ADC Reg D 11 o equ ADC Reg 0 12
24. ar zmezratirz ae TS 45 zar alsz hz szlderzd ta a sur ace 5r cease 13 137341 NO gt de il Ee grsirdse to Wal riste deles stc y oz Wa em bo vou ins dz a ses 2 1 Hei 139 dipped iro 2 into 3 tcazed Fn e n a tank s si any C the Lao wrirg nus ba hop H sa mv and and Tas is esaccinll If cirsi7 ney onarate ad cod Temcerahres whae codenzilizr cen 2zzdugs ard ver 51 6 HASSE 12 pares cipe avs ahs lu insane U al is canis Saude Ihe USS 001 nas ate devises solderse i Sual igh vx it Peat ha ie ces masz Tbe hae costars a Us 135226123 yeni ar Gr oll 3 a smell tazr mal mass may zdzed to the sensar t iva pagelas Patios nal n the qlr tempere Temperature Rise of LM3B Due Ta Self heating Thermal Resistance TO 14 hoheat sink unallheot ln noheotsink 811 ni Ae 5 l 816234 An Cv rk 150 Cw HATIN 30 0 TIA H gt nohcatsink small heat iin noheatsink heat Nn 270 PRAES
25. bU bY g Csa 0010 ZU ZU ZU ZU ZU SE U E 1 0018 ZU ZU ZU ZU ZU ZU ZU bk v UUZU bU ZU amp amp 51 SU ZU ZU ZU 4 DIV VUZE ZU ZU ZU SB bY b 39 bs iens fetum F A UUSU b b 08 ZU ZU ZU ZU my 0038 ZU ZU ZU bl ZU bU ub Ya lt gt 2 ens Av Ween RSP Figure 3 9 Uploading the Code to the Microcontroller Using IC Prog 3 Integrating the Designed Circuit with the Software The PIC16F877 microcontroller is used in the design since it has an analog input capability The RAO pin 2 is used as an input for the temperature sensor LM35 wherein the output voltage of the sensor is proportional to the temperature the sensor detects The actual voltage of the sensor generates is 10 millivolts per degree centigrade A capacitor is connected to the sensor as recommended by the fabricator of the LM35 to see best results A transistor is connected at RE2 pin 10 which acts as a switch to supply the 12 volts motor fan Port B RD6 and RD7 are used for the LCD display A LM7805 is used to regulate the voltage to 5 volts for the supply of the microcontroller and LCD display The RAO pin 2 is used as an analog input for the microcontroller The analog value generated by the sensor is converted into its digital value internally by the microcontroller The microcontroller will send a value to RE2 which is conne
26. inc gt config _XT_OSC amp WDT OFF 8 PWRTE ON amp OFF amp BODEN OFF amp ALL 1 General Purpose RAM location STATUS reg RP1 RPO X Bank 0 RP1 RPO 00 20H to 7FH 96 bytes Bank 1 RP1 RPO 01 20H to 6FH 80 bytes Bank 2 RP1 RPO 10 10H to 6FH 96 bytes Bank 3 RP1 RPO 11 10H to 6FH 96 bytes Note common access Bank 0 to Bank 3 70H to 7FH 1 Variable Declaration ADC Reg equ H 20 Temp Curr equ H 30 Temp_BIN equ 32 PWM Count H 33 Waitl Val equ 7 Wait2 Val 72 5 Msg Num equ H 73 1 79 temporary variable Temp2 equ 7 I Temp3 equ 7 4 equ 7 W TEMP equ H 7D temporary variable W STAT TEMP equ 7 2 temporary variable for STATUS PCLATH TEMP equ 7 LCD RAM Buf equ 20 1 Reset Vector Starts at 0 0000
27. of the design requirement for the degree in Bachelor of Science in Computer Engineering Maoh 5 23 Dr Felicito S Caluyo Dean School of EE ECE CoE ACKNOWLEDGEMENT We thank the Lord for all the blessings you have given us for the lives you have given to us Without your power and your guidance we would not be able to finish this work We would also like to thank our parents for without them we would not be where we are today Our parents were the ones who guided us and provided us our wants and needs They are our inspirations in finishing this work Now we want to return a part of their hard work by means of this project We would also like to give thanks for our friends and family members for giving us support in every endeavor we undertake 5 TITLE PAGE APPROVAL SHEET ACKNOWLEDGEMENT TABLE OF CONTENTS LIST OF TABLES LIST OF FIGURES ABSTRACT Chapter 1 DESIGN BACKGROUND AND INTRODUCTION The Design Setting Statement of the Problem The Objective of the Design The Significance of the Design The Conceptual Framework The Scope and Delimitation Definition of Terms Chapter 2 REVIEW OF RELATED LITERATURE Chapter 3 DESIGN METHODOLGY AND PROCEDURES Design Methodology Design Procedure Hardware Design Block Diagram Schematic Diagram List of Materials Software Design System Flowchart Prototype Development Chapter 4 TESTING PRESENTATION AND INTERPRETATION OF DATA T
28. reading will serve as the input to the PIC16F877 microcontroller The LCD panel will display the measured temperature with the corresponding speed of the fan The PIC16F877 microcontroller is programmed to make decisions and perform functions based on predetermined situations It will send a function to set the motor speed of the electric fan to the corresponding temperature Lastly the circuit will continuously be activated unless the user wants to turn of the system 2 Creation of the Software The Liquid Crystal Display LCD which serves as the display is controlled by a driver software The microcontroller is able to store and run a program that can be programmed to perform decisions and functions based on predetermined situation In programming the PIC microcontroller the steps made was formulate the code compile the code and burn the code into a microcontroller The MPLAB IDE compiler is used in the system The source code will be first saved as a text file and will be run through the compiler As shown in Figure 3 8 The compiler will read the saved text file and compiles it to its equivalent machine code hex file The IC Prog is used for the hex file which is uploaded to the microcontroller As shown in Figure 3 9 The central processing unit of the microcontroller will be responsible running the programmed codes The driver software will display messages on the Liquid Crystal Display on what speed of the fan based on the meas
29. 0 6 2023 37 38 5 1850 35 C 36 C 4 1670 33 C 34 C 3 1450 31 C 32 C 2 1225 29 C 30 C 1 803 27 C 28 C 0 0 26 C Below In Table 4 3 Fan Speed and Corresponding Revolution per Minute as shown above the result was that the fan speed increases as temperature increases and vice versa From the data it can be seen that the fan speed varies because the measured RPM revolutions per minute for every fan speed is varying Testing on Inflow Direction of Air versus Outflow Direction of Air The purpose of testing the inflow direction of air versus the outflow direction air is to determine which is better inflow or outflow as the researchers conducted a series of testing on the temperature inside the CPU The researchers tested this for both instances wherein the device was not installed and when the device is installed To perform the testing of the device on which airflow is better the following procedures were made 1 Properly place the hardware in the CPU 2 Place the fan in an inflow direction of airflow 3 Record the results obtained 4 Reverse the fan in an outflow direction of airflow 5 Record the results 6 Compare the results 7 Repeat procedures 1 6 after installing the device After four hours of operation without using the device the computer temperature was able to reach 479C 489C Using the device the results to lower the temperature are the following Tab
30. 21217 ray f BIA CPIM Note TU 2308 inie Desonrd wisi dirige lo tle Jevisy sesar sid AS ssseilizslizne dz nol puly 110 Area ees Han Nee 1 Note 11 rode 136 27 dezieraed a 5 eau Note 12 SHAS Huare ng eho and Ihar kaam Ed ic sarden 11422 Briere n a sitan Bona one er 10 s 102 rim de nes Typical Performance Characteristics Thermal Hes ba Ali A Gu EK FHI Thermal in Dll Both Per CET OF FHA UE IL Cure vs Tempernture 4 vel 2 1 La nt CERE EMIT 1E E Ti TUF Ai E Hamm Vokes aa 7 ma WY FI FERE Minimum Supply Volinge Temperature Themi Response Contant OF F MEL Curraril 15 Temperature Cin cireut of Figur THI ELT PEHT ELES Im i a 11 E SIF RINWILEE ACCUFDE 95 Tong od bane
31. 35 50 calls 18 24 34 34 36 average calls 25 34 35 35 calls 26 34 35 35 26 average calls 35 35 36 41 calls 36 44 35 35 34 average calls 45 34 35 37 calls 46 48 35 35 40 average calls The room temperature was at 25 degree Celsius After performing the test on the server as shown in Table 4 9 Test on the Server after Reaching Steady State it showed that after the server reaches its steady temperature The server s temperature was maintained to 35 degree Celsius The temperature changes for a while after few hours but will still return to 35 degree Celsius The number of phone calls did not have an effect on the changing of server s temperature Chapter 5 CONCLUSION AND RECOMMENDATION Conclusion The researchers were able to develop a new hardware called Microcontroller Based PC Thermometer with Regulated Fan When the system was completed the researchers gained new knowledge on how to use a microcontroller thermal sensor and how to integrate these components together The PC thermometer with regulated fan was able to display the temperature inside the CPU using the thermal sensor and LCD display The speed of the cooling fan was proven that it varies depending on the measured temperature through the use of digital tachometer Through the testing it showed that the temperature inside the body of the computer was maintained to 34 36 degrees Celsius when the computer is running at 48 hours at room temperature o
32. 77 PINOUT DESCRIPTION PLZZ ree Burffar mur Description mume Pin Pitt Piri Type P TARTI KI EE ESTNE Inpakker yal deck KONT abor ear Cor I sr rssnalor V gs wee Has FS IZ ur a ls wr rh has 714 doe mE cc L7 Emrcter H rale EAE gt Rashi Za Rael opr s Pra ra n mlag estne rpt Ts Fl uj 10 der FORTA 1 TT RAC cun eles be TT Res be L1 TT cun be inp roga 312121 riser ce XAR VERA Il Re can 3152 ar ingle 27 pesr ve malag re vr cr agi 4 7 x BT Rad slas Er Input Po vs nas Clylpulis oper dier yun TT RAS cun be l xn oer zFr nous s nal FOR drebon W por can t sot Fr Fr2 mer ITET2 24 42 on al inpats FRITT EE RPC can alas Fr eternal br T pln 281 ac aT 1 x TT FR at x TT TRATUM 3 x TT can slat Er Ibo be volage pres rare in pul F 37 x TT gs alt x TT qs al RATAT 3 mil
33. IT still ai m oallaaearti ony nica W papat L7 JM E 50 8 Small Guillne Molded Package S yer an nin 22 251 4 Order Number LM35CZ LMISCAZ or LM35DZ Order Number LM35H LMSAH LH SCH LM35C AH or LMSSOH See NS Package Number TO 202 Plastic Package 134 T2 NI See NS Package Number 2034 Order Number LMSS5DM See NS Package Number Typical Applications URLE S DELTE FIGURE 1 Basic Centigrade Tamparatire Sensor 72 2 U Sti Order Number 50 See NS Package Number IAA EM wa ollis v tad P 124 m cant re denn WW eA 4 re vey P 509 II 191 ov gt k F FIGURE 2 Full Range Centigrade Temperature Sensor S10SU9S aJnjeJaduio 1015129 4 aqsew1 v3seWT 23SeW1 VSEIW1 S W 1 Absolute Maximum Ratings iso 10 If Milltary Aerospsce specified devices sre required 50 12 please contact the National Sales Phase 60 suconds 21502 Office Distribulors for availabilily and specificalions Infrared 45 seconds prec Supply Voltage AN ZSD Susceylibiliby Nele 11 2590 Oulpul Vollagu 1 0 Specilied Operating Temperature Pange 10
34. Interrupt bsf INTCON GIE Enable All Interrupts 1 Main Program Starts Here Main nop goto Main 1 F The Interrupt Service Routine ISR routine Save Registers movwf W TEMP F W gt W_TEMP movf STATUS W STATUS gt W movwf STAT TEMP gt 5 bcf STATUS RPO Bank 0 Check which interrupt has occurred btfsc INTCON TOIF 0 Interrupt goto TMROint I Other causes disregard RestoreReg Restore Registers movf STAT TEMP W STAT TEMP gt W movwf STATUS W gt STATUS W TEMP W F W_TEMP gt W retfie Return from Interrupt TIMER 0
35. Microcontroller Based PC Thermometer with Regulated Fan By James Christian B Aspillaga Reinald Carlo A Roque Ishmael Angelo F Sanchez ITI A Design Report Submitted to the School of Electrical Engineering Electronics and Communications Engineering and Computer Engineering in Partial Fulfillment of the Requirements for the Degree Bachelor of Science in Computer Engineering Mapua Institute of Technology January 2009 Approval Sheet Mapua Institute of Technology School of EE ECE CoE This is to certify that we have supervised the preparation of and read the design report prepared by James Christian B Aspillaga Reinald Carlo A Roque Ishmael Angelo F Sanchez III entitled Microcontroller Based PC Thermometer with Regulated Fan and that the said report has been submitted for final examination by the Oral Examination Committee Prof Gil Astrophel Orcena Reader Adviser As members of the Oral Examination Committee we certify that we have examined this design report presented before the committee on December 17 2008 and hereby recommend that it be accepted as fulfillment of the design requirement for the degree in Bachelor of Science Computer Engineering Engr Eliza Agpoon Panel Member 2 Engr Ronina Caoili Panel Member 3 This design report is hereby approved and accepted by the School of Electrical Engineering Electronics and Communications Engineering and Computer Engineering as fulfillment
36. Tp 5 0 my zr Line 250 PE 31 AV zVaz 30 0 2 my Pv Quicscunl Current vu SV 250 pA Nulo 91 Yas FIV 138 p Vo t 30V 2h C pA 30 141 Change 4M Ms GOV pA Quiescent Current AM Vs 3 0 31 Tempcral rz 10 7 Covtiicienl of Quicscunl Current Minirriurri 15 20 15 2 0 G for Ralud Accuracy Figure T Leny Slabiliby for 0 08 10 08 1000 hors Note Nega slizn nee redd 31 sansa juni ion sing oa W ly ii QK das iss nag sat be s as md ipd na 219 nena dies pesti crece islar Note 4 Tysisd ze quern seid ard C355 155 9 n pei soi Note Des on lahs as nerd ca aec pend 124 de ver DMA and sippy wage o ages Meats ant sed o roria Note amp n boldlace ove Fre Wl ra epee rine Note 7 amp rcirazy 5 BAMA as dan accwiena c 13 asi he nes opt 24 spe des dens 24 sols ga end srpy elie Caesa il CI Note amp neatly Fs as he nes e to Fir rsen pest n 2 me rnan dan asc slr nc nent nan dos Note X ipi 2 IT ANA
37. ave massive heat sinks but the server also gets fully loaded with fans In extreme cases liquid cooling is necessary The bad news is that things are getting worse Processor speeds are going up heat generation is climbing too Computers are now very important to our daily lives They are used in businesses for educational purposes and almost everything can be done using a computer That is why proper care for these computers is very essential Some people use their computers for a long period of time One problem that may occur is overheating of the computer resulting to loss of valuable data and even worse destruction or cutting short the life of the computer system s components For servers temperature monitoring is an issue if the server becomes too hot it can cause to down time in servers The cost of a catastrophic server failure can be considerable Much costs would be met if the server goes down There is the cost of replacement loss of e commerce business loss of customers details waste of staff time and the other associated costs Statement of the Problem Computer equipment ages faster when it gets hot In general computer operates more reliably and has a longer life in cooler conditions The effects of prolonged running at high temperatures can be unpredictable and are not always characterized by catastrophic failures For individual machines in domestic or small office conditions the internal fans and cooling me
38. ay ir Ey pes ilt fiw s series DO dar ger sash ze foll iq series with zi zr 1 uF output ta greind arz een Lee ee sacer Payee 23 34 are Typical Applications zonr nui Unam m TEL Z L TL bit if FIARE 5 Ramo arian rounded Seneor FIGUAE 7 Temperature Sensor Supply 577 ba 150 ther FIGUHL 4 Same Cio r CI L zh HOT 2 a 1 d Vea Trama FEM m ee FIGARRE Remate Temperature Biar Ground Kn ano Tam 112 01 LTH xl FIGAPRE Temperature Bens nad lur hr YA FIGURE 13 Tacrmomecter Typical Applications icc o um aw FALSCH E RESCUE FIGURE 11 Centigrade Thermamreter Analog Meier T 21110 12 FIGURF 12 Fepandad genla Thermometer 00 ta Fahrenheit far Example Shown FIGURE 13 To Digilsl Canverl r Serial Oulpul 126 Full Scale ee TN mA SW 5 aw T MA FIGURE 14 Temperalure To Cigilal Para
39. ce the temperature sensor near the processor or heat sink where it emits high temperature inside the computer Make sure all wires and connections are not entangled Choose an available connector of the computer s power supply unit and make sure it is the right source 12V Connect the power supply cable of the device to the available connecter of the computer Make sure the computer is turned off before connecting the device 10 After connecting the power supply cable observe for the display the LCD 11 Make sure the casing side panel where the fan is installed is properly screwed to ensure proper airflow inside the computer 12 The device is now ready to use APPENDIX E User s Manual User s Manual Microcontroller Based PC Thermometer with Regulated Fan Make sure the device is properly installed by following the steps on the Installation Manual The device can be used as soon as it is installed properly The LCD panel serves as the display Temperature Reading C Generated Fan Speed The temperature inside the computer can now be monitored which is displayed on the LCD panel The fan speed depending on the measured temperature is generated automatically
40. chanism are usually sufficient to keep the temperature within safe But if the machine is used in a business wherein the uptime of the machine is critical and is used for a long time Temperature monitor is important Temperature monitoring is essential for CPU especially if it is used for server Failure to monitor temperature could result to unnoticed heat build ups in CPU that can reduce the life of components decrease reliability cause untold problems and expense The Objective of the Design The objective of this project design is to measure the present temperature inside the computer and will be displayed on its casing for easier temperature monitoring and to create a prototype of a computer 10 thermometer that can be placed the central processing unit as additional hardware Using the PIC microcontroller the team would design an external display of the temperature on the CPU Through this external display temperature monitoring will be easier especially on servers that are sharing to one monitor since it will only need one look in the CPU to know the temperature Another objective of our design is to determine whether which airflow is better either inflow direction of air or outflow direction of air The Significance of the Design The design of the device would be very helpful to computer users because it can help prevent overheating of their computer through proper monitoring of its temperature and applying a t
41. circuits Unlike a logic gate which has a fixed function a PLD has an undefined function at the time of manufacture Computer Concepts and Fundamentals Rectifier Diode a semiconductor device that converts ac into pulsating dc one part of a power supply Electronic Devices 2002 Resistor the simplest passive element It is a device that has the ability to resist the flow of electric current that is measured in ohms It is usually made from metallic alloys and carbon compounds Fundamentals of Electric Circuits 2004 16 Thermistor a resistor whose resistance varies as function of temperature Thermistors are used in electrical devices such as thermometers and thermostats that measure monitor or regulate temperature Fundamentals of Electric Circuits Transistor a semiconductive device used for amplification and switching applications ectron c Devices 2002 Tachometer an instrument that measures the speed of rotation of the engine in revolutions per minute rpm University Physics Voltage electric potential expressed in volts University Physics 17 Chapter 2 REVIEW RELATED LITERATURE AND RELATED STUDIES In an article entitled Cooling Down with Fan Speed Control on September 28 2000 Bruce Denmark conducted a study that gave an important contribution to our study which is to develop a device that can display the temperature of computer and maintain a desirable temperature inside the compu
42. cted to the transistor and gives a corresponding voltage depending on the value the sensor generated and then the microcontroller also send a value to the LCD to display the fan speed and the measured temperature by the sensor 4 TESTING PRESENTATION AND INTERPRETATION OF DATA When the device has been completed testing was done to determine if the device is working properly The device must be able to measure the temperature inside the computer and it will be displayed or shown outside the computer s casing Various tests are needed to determine the effectiveness and reliability of the device Testing using Multimeter The purpose of testing the prototype using the multimeter is to prove that the fan speed increases as the voltage also increases Using the data gathered from the test the researchers can also calculate the power used by the device To perform the testing of the device with a multimeter shown on Figure 4 1 Testing the Prototype with Multimeter the following procedures were made 1 Place the sensor inside the digital oven 2 Turn on the oven and adjust the temperature to the minimum limit of fan speed one 1 3 Wait for the temperature to stabilize 4 Tap the multimeter probes to the wires that connect the device and fan 5 As fluctuations occur record the read out voltage that hold the longest 6 Redo procedures 2 to 5 adjusting the temperature to the minimum limit of each fan speed
43. easuring the temperature it will be displayed on the LCD panel the corresponding speed of the fan will be generated accordingly If the user wants to turn of the system the process will end if not the process will start again at measuring the temperature c Prototype Development In creating the design the researchers gathered the necessary components and information needed in the design Components such as hardware used were identified using the data sheets and through research The components used were the solutions to the design problem The following steps were used in creating the design 1 Creation of the Circuit With all the information and possible solutions gathered the researchers collected all the necessary components and designed the complete circuit of the system The researchers used Electronics Workbench MultiSim9 as a tool in designing the circuit The tool used is an interactive and user friendly application that provides circuit simulator and new integrated circuits The device must be first connected to the computer s power supply Once the computer is turned on the device will also be turned on The LCD panel will be activated and will show the measured temperature and its corresponding fan speed The temperature will be obtained using the LM35 thermal sensor and it will be in degrees Celsius While the device is running the thermal sensor will continuously measure the temperature inside the computer and this
44. ed This is where all the hardware components and the software to be used will be determined 25 Hardware Design 1 Block Diagram 4 sss T Supply voltage Regulator Voy b Figure 3 2 Block Diagram In Figure 3 2 as shown above the power supply of the CPU will be used as the main source of the hardware The 12 V will supply the cooling fan and the 5 volts is for the sensor and the microcontroller When the sensor read temperature it will send an analog signal to the microcontroller The microcontroller will convert the analog signal into its digital value in order for it to be displayed in the LCD and at the same time it will send a signal to the transistor in order to trigger the cooling fan 26 LC neureu s g g 1614 3 118491314 4 zasa zas 72 Poe Edsa coy 2 iz 7 221 vas 05 eos 125 25 oasis 1439 25 ME ued X17338 z422 15011 123 101044 P INSEL OSOTL 034 1no 12 2250 RI Pr eu i 5454 5093 NIN1D T3ISO 5454 503 SSA j dSd aa Ht AP SSA IET pin ss IN GTHA mir eau TWH eS 93 iw tva 1 7 354 90 ouv ddA
45. emperature dependent fan to maintain desirable temperature The device will be placed inside the computer The device will measure the temperature inside the CPU and introducing a fan into the system to exhaust the hot air around the chassis and the heat generating components When it becomes too hot the fan s speed would be faster and if the temperature is on the average the fan s speed would be normal just to maintain the desirable temperature Automatic fan speed control without the need for host intervention is particularly useful in PC applications for a number of reasons Once configured it enables the system to react to temperature changes and ensures that the fan will run 11 only as fast as required for any given temperature minimizing the power consumption and reducing the noise level generated by the fan The Conceptual Framework The device is microcontroller based to monitor the temperature and regulate the speed of the fan It contains all the programs needed to have the accurate reading of the thermometer and to control the fan speed There is also an LCD display that indicates the current temperature inside the casing Refer to Figure 1 1 for graphical presentation of the conceptual framework Figure 1 1 Conceptual Framework 12 6 Scope and Delimitation The study was concerned with the development of a design called Microcontroller based PC Thermometer with Regulated Fan that serves as a cooling and temp
46. er upton 335 ab Badal r i Dir upton 3 335 ape dra FORTZ izzu ielizal uut B 5 I raer z5cilaber culpa 27 HOD PAS ke i 5 meri 2571 2b pul or Cape E m akole inp pat xL RE yv aa desk 1 r b Fl anc ZZ rode Enan D m T nr EFI TEE 1 ro or Jele IC Fee ROD D merk p 5 BEGG cor be cum 2 Fy FA Click ROT caw Foie zwObrenenz ver Grow 3 1216 ard ars VD i supple 12 15412 33 pias Lege nal raruilp t H bo aw T TI Input ST Setrit Tiger Habs 1 Tas bi a isa 41 11 Tigga rpd her cer gee lle 11 14 2 agb a is 4 Tigger Tak mede 1 gaper rpn wher zor perec 19 HC mode 324 a CTS input cos sm 0001 Technolgy Inr penas 7 PIC16F87X TABLE 1 2 PIC1SF874 PICTSFA
47. erature monitoring of a computer The research study set the scope and delimitation as follows 1 The prototype can be place in any computer that has CD DVD ROM rack of the CPU as an additional hardware 2 The LCD will only display the current temperature inside the casing and corresponding fan speed 3 The device receives its power from the computer s PSU Power Supply Unit that produces 5V and 12V 4 The sensor can be mounted in any part of the CPU that needs temperature monitoring 5 The thermally activated fan is included to help maintaining desirable temperature inside the CPU and 6 The prototype is designed for server use The delimitations of the design of the Microcontroller based PC Thermometer with Regulated Fan are as follows 1 The LCD can only display the current temperature inside the casing in degrees Celsius format 2 There should be an available connector from the PSU Power Supply Unit as a source of power 13 3 The casing has to be modified to acquire the full potential of the device 4 Different model of the internal parts of the motherboard has different tolerable heat and 5 Different design of CPU has different airflow which can lead to different result if tested with another computer 7 Definition of Terms The group encountered some terms that were used throughout the study These are as follows American Standard Code for Information Interchange ASCII a standard for assigning numerical
48. esting using Multimeter Testing Fan Speed with Digital Tachometer vi vii m OQ Q N N Testing on Inflow Direction of Air versus Outflow Direction of Air Testing on a VOIP server Chapter 5 CONCLUSION AND RECOMMENDATION Conclusion Recommendation References Appendices Appendix A Source Code Appendix B PIC16F87x Data Sheet Appendix C LM35 Data Sheet Appendix D Installation Manual Appendix E User s Manual 33 37 41 41 41 LIST OF TABLES Table 3 1 List of Materials Table 4 1 Test of DC Fan without Device Table 4 2 Test of DC Fan with Device Table 4 3 Fan Speed and Corresponding Revolution per Minute Table 4 4 Inflow Direction of Airflow Table 4 5 Outflow Direction of Airflow Table 4 6 Outflow Direction of Airflow since Start Up Table 4 7 Inflow Direction of Airflow since Start Up Table 4 8 Test on the first few minutes after boot up at initial CPU temperature of 299C Table 4 9 Test on the Server after Reaching Steady State LIST OF FIGURES Figure 1 1 Conceptual Framework Figure 2 1 Fan Speed vs Fan Voltage Figure 2 2 Fan Current vs Fan Voltage Figure 2 3 Linear Fan Control Circuit Figure 2 4 Thermistor Based Fan Control Circuit Figure 3 1 Design Procedure Flowchart Figure 3 2 Block Diagram Figure 3 3 Schematic Diagram Figure 3 4 LM35 Sensor Figure 3 5 PIC16F877 Microcontroller Figure 3 6 Cooling Fan Figure 3 7 System Flowchart Figure 3 8 Compiling the Code us
49. f 25 degrees Celsius hardware can be a big help for monitoring and maintaining proper temperature inside the CPU Recommendation Several improvements can be applied to the device to further enhance its capabilities in monitoring the server to avoid downtime Humidity control system can be added in the prototype to maintain proper humidity in the server room It can be a big help to avoid moisture whenever it is too humid in the server room Power sensor can also be added before the UPS It can detect and report on the availability and loss of AC power It will be a big help to the area that typically face power outages and if the administrator want to be alerted before the UPS goes down too REFERENCES Christensen Jim Electronics Design Strategy News March 21 2002 Denmark Bruce E ectronics Design Strategy News September 28 2000 Guy John Zlectronics Design Strategy News March 4 2004 Predro Myke Programming and Customizing PIC Micro Microcontrollers Second Edition April 2000 Predro Myke Handbook of Microcontrollers December 1997 Gay Ken Electronics Design August 29 2007 Vallis Darrin E ectronics Design 2004 APPENDIX A Source Code 2K X 2K lt K KK lt lt lt x X X X X lt X X X lt X X lt X lt X lt X KOK 5 File FANSPID4 ASM 8Mhz processor 16F877 include lt P16F877
50. flow Direction of Airflow since Start Up Temperature Time Duration 32 339C Trial 1 Trial 2 Trial 3 349 44 secs 32 5 5 58 secs 350 C 52 secs 1 min 12 secs 1 min 27 secs 36 2 min 32 secs 2 min 52 secs 2 min 48 secs 379C 3 min 40 secs 3 min 27 secs 3 min 33 secs 38 9C 3 min 32 secs 4 min 17 secs 3 min 59 secs 39 9C 4 min 43 secs 5 min 33 secs 5 min 41 secs From the data in Table 4 6 Outflow Direction of Airflow the results were the temperature range was 329C 399C The computer was turned on and was operating for four hours and the temperature has reached only at a maximum of 39 Table 4 7 Inflow Direction of Airflow since Start Up Temperature Time Duration 32 339C Trial 1 Trial 2 Trial 3 34 33 5 5 26 secs 42 secs 359 C 56 secs 1 min 22 secs 1 min 12 secs 369C 2 min 12 secs 2 min 37 secs 2 min 22 secs 379 3 min 35 secs 3 min 12 secs 3 min 52 secs 38 9C 3 min 49 secs 4 min 15 secs 4 min 8 secs 39 9C 4 min 37 secs 5 min 24 secs 4 min 56 secs 409C 6 min 09 secs 7 min 13 secs 6 min 43 secs 419C 3 min 32 secs 4 min 18 secs 3 min 42 secs From the data in Table 4 7 Inflow Direction of Airflow as shown above it was observed that when using the device since startup time the temperature range is 32 419C computer unit was operating for a
51. g Diode LED a semiconductor diode that emits light when conducting current and is used in electronic equipment especially for displaying readings on digital watches calculators etc Computer Concepts and Fundamentals Linear Regulation adjusts the dc voltage across the fan using a linear regulator Electronics Design Strategy News Microcontroller single purpose processing units designed to execute small control programs sometimes in real time The program is frequently stored on the microcontroller in an area of nonvolatile memory Handbook of Microcontrollers 15 Multimeter an electronic measuring instrument that combines multiple functions a combined voltmeter ammeter and ohmmeter Fundamentals of Electric Circuits Nybble the computing term for a four bit aggregation or half an octet an octet being an 8 bit byte As a nibble contains 4 bits there are sixteen possible values so a nibble corresponds to a single hexadecimal digit Computer Concepts and Fundamentals PIC a family of Harvard architecture microcontrollers made by Microchip Technology derived from the PIC1640 originally developed by General Instrument s Microelectronics Division The name PIC initially referred to Programmable Interface Controller but shortly thereafter was renamed Programmable Intelligent Computer Handbook of Microcontrollers Programmable Logic Device PLD an electronic component used to build reconfigurable digital
52. he fan speed changes When the fan is running at higher speeds it will consume more power and when the fan is running at lower speeds power being consumed decreases Testing Fan Speed with Digital Tachometer The purpose of testing the device with a digital tachometer is to prove that each fan speed varies depending on the temperature the researchers used a Digital Tachometer to measure the RPM for each fan speed To perform the testing of the device with a digital tachometer shown on Figure 4 2 Testing Fan Speed using Tachometer the following procedures were made 1 2 Stick the reflector in the middle of the fan Place the sensor inside the digital oven Turn on the oven and adjust the temperature to the minimum limit of fan speed one 1 Wait for the temperature to stabilize Position the tachometer in front of the reflector sticker As fluctuations occur record the RPM that holds the longest Repeat procedures 3 to 6 adjusting the temperature to the minimum limit of each fan speed Figure 4 2 Testing Fan Speed using Tachometer Table 4 3 Fan Speed and Corresponding Revolution per Minute Fan Speed Revolutions per Minute RPM Temperature 15 2847 55 C Above 14 2760 53 54 13 2698 51 52 12 2640 49 50 11 2556 47 48 10 2443 45 46 9 2364 43 44 8 2263 41 42 7 2175 39 4
53. ing MPLAB IDE Figure 3 9 Uploading the Code to the Microcontroller Using IC Prog Figure 4 1 Testing Prototype with Multimeter Figure 4 2 Testing Fan Speed using Tachometer Figure 4 3 Softphones used for testing in Voice over IP server 5 This device is a temperature monitoring device with regulated fan for computers The purpose of this study is to develop a circuit that adjusts the motor speed of computer cooling fan s depending on the measured temperature A thermal sensor is used to measure the temperature of the computer The device is also integrated with a microcontroller which enables the cooling fan to attain a variable motor speed depending on the measured temperature Varying the motor speed of the fan results to lesser power consumption The researchers used the multimeter to test the conservation of power consumption and a digital tachometer to test the varying motor speed of the fan Findings of this study showed that using a thermal sensor microcontroller and other components a computer cooling fan can vary its motor speed and reduce power consumption Keywords Thermal sensor Microcontroller Computer Chapter 1 DESIGN BACKGROUND AND INTRODUCTION 1 The Design Setting Over the past ten years computers have increased their heat output considerably Even a cursory glance at a modern server reveals the huge amount of effort that the designers had to take to keep the computer cool Not only do the processors h
54. le 4 4 Inflow Direction of Airflow Temperature Time Duration 479C 489C Trial 1 Trial 2 Trial 3 469C 1 min 1 min 11secs 56 secs 450 1 min 30 secs 1 min 43 secs 1 min 505 5 449 2 min 42 secs 2 min 26 secs 2 min 39 secs 43 C 5 min 46 secs 6 min 12 secs 5 min 53 secs 42 20 min 5 secs 18 min 08 secs 18 min 47 secs Table 4 5 Outflow Direction of Airflow Temperature Time Duration 479C 489C Trial 1 Trial 2 Trial 3 469C 44 secs 1 min 10 secs 22 secs 45 1 min 22 secs 1 min 55 secs 48 secs 449 C 2 min 26 secs 2 min 26 secs 1 min 22 secs 439 4 06 5 5 4 min 40 secs 2 49 5 5 429 11 min 32 secs 18 22 secs 16 min 13 secs From Table 4 4 Inflow Direction of Airflow and Table 4 5 Outflow Direction of Airflow it shows the time it takes to lower the temperature and also the time it takes until the temperature is stable from the highest temperature obtained Also from the data gathered the result was that the device was able to reduce the temperature inside the computer from the highest reading which is 489C down to 429C The computer was turned off for four hours for the temperature to go down The device was installed first before the computer was turned on and the results for temperature reading are the following The initial temperature is 32 Table 4 6 Out
55. llel TRI STATE Gulpuls ior Standard Dnia Busia interface 12870 Full Scala Typical Applications wT wm 7 N W us aaa ova Bl IN tee Teast 7 1 1 451 Ir le FIGURE 15 Bar Graph Diapiziy Oot Madaj T domi 7 FIGURE 1G 13335 Vr i Voltage To Frequency Carwerber Andisalated Ou put PC ip I50 C 20 Hz 1p 1400 Block Diagram Physical Dimensions ncc irillimcre s 7 12 1170 1115 nmm u pi 1 ELI 1 242 nis 003 ILLE ER maii 54 5 TOE Matal Gan Package H Order Number LM35H LMa5AH LM3235CAH or LM35DH NS Package Number HOSH XC ELIT 7 CHE UE aq e a WA LAS LIE Y MS CTI nye nrn AH T Ff MIN Vix 308 271 aL vue zm 50 8 Molded Small Package Order Humber NS Package Number Physical DIMENSIONS ehl UR 11335 1941 109 1335 Tr me t 125 0365 F
56. lls in between hours of testing 6 Record the data gathered Figure 4 3 Softphones used for testing in Voice over IP server Table 4 8 Test the first few minutes after boot up at initial CPU temperature of 299 Room Temperature Temperature Duration 25 30 11 sec 25 31 46 sec 25 9C 32 1 min 25 sec 25 C 33 1 min 56 sec 25 C 34 2 min 42 sec 25 35 2 min 56 sec 25 C 36 4 min 24 sec 25 C 37 5 min 10 sec 25 C 36 6 min 16 sec 25 C 35 6 min 4 sec 25 C 36 7 min 8 sec 25 9C 37 7 min 16 sec 25 C 38 15 min 27 sec 25 9C 37 17 min 42 sec 25 C 36 18 min 51 sec 25 C 35 22 min 17 sec From the data on Table 4 8 Test on the first few minutes after boot up at initial CPU temperature of 290 it was shown that on the first few minutes after booting up the temperature of the computer was not stable The temperature was continuously increasing and decreasing especially on the first seven minutes of the computer after boot up then slowly changing on the next few minutes until it reaches a steady temperature Table 4 9 Test the Server after Reaching Steady State Hours Duration Lowest Highest Number of Temperature Temperature phone calls 1 29 38 34 calls 2 35 35 32 calls 3 35 35 40 calls 4 35 35 35 calls 5 7 35 35 46 average calls 8 35 36 42 calls 9 16 35 35 55 average calls 17 34
57. ments of a general purpose microprocessor the microcontroller integrates additional elements such as read write memory for data storage read only memory for program storage and input output peripherals The cooling fan Figure 3 6 is used to eliminate the heat produced by the computer The speed of the fan depends on the measured temperature Figure 3 4 LM35 Sensor MOLAN T 1 40 RADAND j 2 e RANAMI LT 3 T AAAI 4 37 RADANG RAJTI az REI RASIANUSE T REDRDUAME REV WANE e a3 O REZICEIAMT mw E ai T 4 az ves a w 22 za 2 0 3COTHOSO TCKI 25 T RCTRX UT 2 4 8 zs CET ACE z 22 mcssDesDA RDOFSPO z 7 21 2 Figure 3 5 PIC16F877 Microcontroller Figure 3 6 Cooling Fan b Software Design The program was developed using the MPLAB IDE Compiler and IC Prog The code was formulated and compiled using the MPLAB IDE Compiler This application is used to convert the code to machine language in which the computer can understand it After co
58. mpiling the code it is now ready to be uploaded to the microcontroller Using the IC Prog application the code was uploaded or burned to the microcontroller using also hardware that is connected to the computer and has the capability of writing the codes to the microcontroller The formulated code includes programs that the major components used in the system These components are the thermal sensor microcontroller and the cooling fan The code is the one responsible for the automation of the whole system It is also responsible in the display of the system through the Liquid Crystal Display LCD As the temperature is measured using the thermal sensor it serves as the input to the code uploaded in the microcontroller The code contains various predetermined situations or functions that correspond to the measured temperature These functions include generating the speed of the cooling fan with respect to the temperature obtained 1 System Flowchart System Flow Chart START Turn on the computer Measure the temperature using the LM35 sensor Display the measured temperature on the LCD panel Generate the speed of the fan to the corresponding measured temperature Figure 3 7 System Flowchart The system flowchart as shown in Figure 3 7 explains how the device works internally The computer must be turned on After the computer is turned on the temperature will be measured by the LM35 sensor After m
59. oto PdoMegbogp 22 movlw LCD RAM Buf movlw D 32 addwf Temp3 F LCD Char Tempi F oto Ld Msg Adr addwf Temp1 W 5 ede movwf FSR Ld MsgLoop movlw 32 bsf FSR 7 Ind Addr Select Bank 1 subwf 1 2 INDF W btfsc STATUS Z movwf LCD DPort 5 goto Ld MsgDone call Pulse EN incf movf PCLATH W goto RAM2LCD2 movwf Temp4 RAM2LCD2X movlw HIGH 540 movwf PCLATH movf Temp1 W addwf Temp3 W call 540 movwf Temp2 I movf Temp4 W movwf PCLATH goto Ld Msg Char Ld Msg Char movlw LCD RAM Buf addwf Temp1 W movwf FSR bsf FSR 7 Addr Select Bank 1 movf Temp2 W movwf INDF incf goto Ld MsgLoop Ld MsgDone return APPENDIX B PIC16F87 Data Sheet MICROCHIP PIC16F87X 28 40 Bit CMOS LASI Microcontrollers Devices Included in this Dats Sheet OWES ES uF e 11745 25 e Ii Microcontroller Features ligh RISC 251 35 eirgle scd insb A amp
60. raga Th Parall gt Slae gt Sart inclement 21736 Me eris The novice diagrarcs zs soten pn ramber 23 pn for gi 1 1 5 19 Afl zir 27 Fiz ar7 1 2 Ire 29 2 ard les abe 1 1 54 13 16 2 16 873 16 876 BLOCK DIAGRAM 3 7 4 2 gm wA 382 3EPFCD HZ gm ws INIST ONS MIX MARIA 335 5 PIC16F87X FIGURE 1 2 PIG16F87T4 AND PIC 16F877 BLOCK DIAGRAM Prixjram FLASH T Memor zA aT 122 Byte 125 Dy nz Ter M Byte 253 Dyes 13 renim F ogram U len hans FI gt rar nulo rcg Jari mny Fo May Ic m Fig cuiu E v v e Aula 1 sneer 2 u RNC ILLI 555 eG Sept Rag cl Fares REQ HT Hu Hits RES REA Sc QS Hp nig CHI ROO Too HLAKKA 3003 7F0 aDz ir2 TF DE IF5 D amp ir
61. ter He said that introducing fan speed control into electronic designs can help in reducing heat problems He also discussed the different methods in which fan speed control can be achieved like Pulse Width Modulation Linear Regulation and DC DC Regulation In Mr Denmark s article he mentioned that as the dc voltage applied to the fan varies its speed and current draw also vary as portrayed in Figure 2 1 He also mentioned that the speed and current of the dc fan are directly proportional to the dc voltage applied as shown in Figure 2 2 E IOI Fan speed current 15 aan to applied lan voltage Figure 2 1 Fan Speed vs Fan Voltage 18 uuu _ Figure 2 2 Fan Current vs Fan Voltage Furthermore an article by Jim Christensen which is entitled Circuit Generates Fan Speed Control on March 21 2002 states that linear regulation can be used to control the fan speed which he showed in his circuit in Figure 2 3 as for our design pulse width modulation is used This study gave the researchers an alternative in producing a fan speed control circuit The group also considered this study to gather relevant information like the components that he used for the circuit this drtult dellwers a cantinuaus and lincar tan control voltage that is peupartional to bemperaturc Figure 2 3 Linear Fan Control Circuit 19
62. th regulated fan Design Procedure The design follows the constructive research method as stated from above On figure 3 1 Design Procedure Flowchart it will clarify the details step by step The design has four parts first is identifying the problem second is collecting information relevant to the study the third is formulating a plan or draft and the last part is gathering the materials needed 23 Design Procedure Flowchart START Identify the problem Collecting Information Relevant to the Study Formulating a Plan or Draft Gathering the Materials Needed Figure 3 1 Design Procedure Flowchart 1 Identify the problem the first thing to do in a project is to identify the problem to be solved In our design the problem we identified is that failure to monitor temperature could result to unnoticed heat build ups in CPU that can reduce the life of components decrease reliability cause untold problems and expense 24 2 Collecting Information Relevant to the Study this part of the study is where research is done to gather important details that can help accomplish the project to be made 3 Formulating a Plan or Draft this part of the study is where the researchers prepare the objectives and tasks to be done needed to finish the project 4 Gathering the Materials Needed this is the last part of the design procedure of our project in which all the necessary tools and equipments needed are gather
63. total of four hours and the highest temperature it obtained was 419C The temperature inside the computer was maintained at a constant temperature and did not increased again After performing all the tests and gathering all the data needed to compare on what airflow is better it can be assumed that outflow direction of air is better These can be seen on the results that showed that from the highest temperature it takes lesser time to lower it comparing on the results when the direction of air is inflow Also from the data obtained when the direction of air is outflow or exhaust the temperature inside the computer is maintained at a lower temperature 399C compared to when the direction of air is inflow which is 41 C Testing on a VOIP server The device was tested on actual application for Voice over Internet Protocol server The prototype was tested in 48 hours uptime of the server This purpose of performing the test is to show how the prototype helps the server in maintaining desirable temperature in the CPU To perform the testing of the device on a VOIP server shown on Figure 4 3 Softphones used for testing in Voice over IP server the following procedures were made 1 Properly install the prototype on the server 2 Make sure that the computers are properly connected with the server 3 Soft phones or IP phones should be properly installed the computer 4 Turn on the server for 48 hours 5 Make random number of phone ca
64. trol focused on the discussion on how to use an LCD The article also discussed the basic pin configuration usually used The article was used by the group to gather information on LCD how they work and how the LCD can be 21 connected to the microcontroller The article is very helpful to the researchers since the article was very in depth in its discussion Lastly Myke Predro 2000 in his article entitled Programming and Customizing PIC Micro Microcontrollers Second Edition discussed pulse width modulation PWM in detail It explained that using pulse width modulation is the best way to handle analog voltages and that PICmicro MCU does not handle voltages very well The study also discussed that analog signals should not be used for data transfer His article was useful to our study since pulse width modulation is also the method we used in our design 22 Chapter 3 Design Methodology and Procedures Design Methodology Constructive research was used as the design methodology The design procedure part will provide further explanation of the method and a step by step procedure will be discussed The research started by identifying the problem Followed by collecting information relevant to the study formulating a plan or draft and gathering the materials needed Figure 3 1 Design Procedure Flowchart shows the procedure in developing the design On the succeeding pages Figure 3 2 shows the block diagram of the PC thermometer wi
65. ured temperature using the LM35 thermal sensor MPLAB DF v7 4fl 02 dea d Checksum UD lt UbUU c ASW 2 atcere Tack 0 cc Tack Tat amp ble Daclatacicn n 2 warcacde 2 tawzeotaty for T mo oed 4 gt 4 5 gt 0 0 lt bh bain lano deb t E XY YE 0s 755 zw 1 0000 SPAA MAAA Z 2 Z 2 Z 2 MALA 00999996 UUUE 1814 2228 1818 1814 2828 242 fe 0010 228 AAAA 0018 1814 1418 1814 2828 0020 1814 1818 ZAUD 000000 0028 ZUZU ZUZU ZUZU ZUZU ZUZU ZUZU ZU amp b ZUbC 0030 ZUZU Ub amp l Uu lU amp U 082 2561 l amp D ZU amp U A51 AMA 0058 ZUSE AUD MAZU ZUZU ZUZU 2010 ZUZU 0060 ZUZU ZUZU 2000 Zibo 52 2 ZE Z ZUZU yvvvr UU amp E 2010 ZUZU 3156 UbSE 2030 ZUZU ZUZU TEE VULU ZUZU ZUZU ZUZU ZUZU ZUZU 2966 2360 3988 UUbE ZU2U 2020 2010 2020 2056 1021 jb amp b SESE 02 203 0600 Ay hs FIER 0000 ZU SE ZU ZU ZU ZU ZU rur UUUE ZU ZU bl b ZU UU
66. values to the set of letters in the Roman alphabet and typographic characters Microcontrollers Architecture Implementation and Programming Boston McGraw Hill Capacitor a passive element designed to store energy in its electric field the most common electrical components It is consisted of two conducting plates separated by an insulator or dielectric It is an open circuit to dc used extensively in electronics communications computer and power systems Fundamentals of Electric Circuits 2004 Celsius using or measured on an international metric temperature scale on which water freezes at 0 and boils at 100 under normal atmospheric conditions University Physics 14 Central Processing Unit CPU part of the computer that holds the main components like mother board and video card This is usually enclosed in a casing Computer Concepts and Fundamentals Current current flow of electric charge The electric charge in a current is carried by minute particles called electrons that orbit the nuclei of atoms Fundamentals of Electric Circuits 2004 Direct Current DC unidirectional flow of electric charge Direct current is produced by such sources as batteries thermocouples solar cells and commutator type electric machines of the dynamo type Fundamentals of Electric Circuits 2004 Frequency the number of times a specified periodic phenomenon occurs within a specified interval University Physics Light Emittin
67. vwf LCD call Pulse EN D 100 5 5 delay call Wait2 P return F Wait1 movlw H 10 approx 50uS delay movwf Waitl Val E Wait1 loop decf Waiti_Val F btfss STATUS Z goto Waiti loop return Wait2 movwf Wait2 Val N x 50uS delay Wait2 loop Waitl Wait2 Val F F btfss STATUS Z 5 goto Wait2 loop return gt Disp LCD Disp LCD1 Set RSO movlw LCD L1 Addr movwf LCD call Pulse EN Set RS1 F clrf Tempi 21 1 movlw LCD Char 1 subwf Temp1 W btfsc STATUS Z goto RAM2LCD1X LCD RAM Buf addwf Temp1 W movwf FSR bsf FSR 7 Addr Select Bank 1 movf INDF W E movwf LCD DPort call Pulse incf Temp1 F goto RAM2LCD1 I RAM2LCD1X f return Disp LCD2 Set RSO moviw LCD L2 Addr Ld_Msg2RAM movwf LCD DPort I Pulse drf Temp3 Set RS1 movf Msg Num W drf 1 movwf Tempi RAM2LCD2 movlw LCD Char Max Ld Msg Adr movf Tempi W subwf Temp1 W btfsc STATUSZ goto RAM2LCD2X j 9
Download Pdf Manuals
Related Search