Leitor RFID
Short Description
Leitor eletrônico de rfid...
Description
Leitor RFID Cartões RFID são normalmente usados para controle de acesso e tickets de ônibus e metrôs. Eles são convenientes porque não precisam de contato direto para transferir informações depara o cartão. Como estes cartões são alimentados pelos pr!prios leitores" dispensam o uso de baterias que precisariam ser recarre#adas. $ara os meus e%perimentos estou usando catrões da &ID I'$ro%. Estes cartões são os mais simples de toda a lin(a de cartões RFID" que somente arma)enam um n*mero de s+rie e não usam cripto#rafia. , frequ-ncia da portadora + de /0k&). 1 primeiro passo + descobrir como desenvolver um leitor simples. 2!s sabemos que o cartões RFID + alimentado pelo campo ma#n+tico emitido pelo leitos. ,s tags3 RFID transferem informação de volta ao leitor consumindo este campo ma#n+tico" que + detectado pelo leitor como uma variação no campo. 3 'ão c(amados de 4 tags5 RFID todos os elementos que arma)enam informações e são m!veis" como o cartão" neste caso espec6fico.
1 pro7eto mais comum de um leitor RFID fa) uso de um circuito ressonante s+rie. Ele consiste de um indutorsimples e um capacitor" e%citados por uma fonte de tensão de bai%a imped8ncia. 'e o 9 do circuito for alto o suficiente" a tensão no ponto de amostra#em :;sample< vai e%ceder a tensão de alimentação. 9uando o RFID + alimentado por este campo ma#n+tico o 9 do circuito cai. 1 resultado + uma pequena alteração na tensão de amostra#em :;sample no circuito mostrados e redesen(ar todo o circuito. Com um a7uste simples eu verifiquei quais alterações aconteciam quando a ta# RFID era submetida a A ou 0 ciclos de frequ-ncia da portadora. =ma ve) que o sinal precisa ser ,C e não DC" eu assumi que a frequ-ncia de transmissão seria 0@k&B B.0k&) ou 0@k&)@ 0k&). Este detal(e eu encontrei em um site que foi realmente *til por conter boas informações sobre RFID?(ttp?instruct.cit.cornell.educourseseeAFinal$ro7ectss/@@c7rGebsiteinde%.(tm RFID?(ttp?instruct.cit.cornell.educourseseeAFinal$ro7ectss/@@c7rGebsiteinde%.(tm.. , tag aparentemente aparentemente codifica o dado usando F'H. ,s duas frequ-ncias representam o @ e l!#icos. Com esta informações em mãos" eu avancei e iniciei o pro7eto do meu pr!prio indutorantena. =ma ve) que eu mantive a id+ia de usar 0@k&) como frequ-ncia da portadora" eu fi) o c>lculo e fiquei com uma indut8ncia de @u& e um capacitor de @nF. Eu utili)ei a se#uinte equação para estimar o n*mero de
voltas que precisaria em min(a bobina?
1nde %" J são o comprimento e a lar#ura da bobina" ( + a altura e b + a espessura da parte condutora. Eu utili)er %Jcm" (cm e b@.cm. 1 n*mero encontrado foi A. Eu enrolei a bobina em uma cai%a de papel que encontrei" de onde eu e%trai o % e J. J. Depois de enrolada" a bobina foi e%tra6da e presa com fita adesiva.
$ara um a7uste fino da frequ-ncia ressonante do sistema todo eu decidi brincar com o valor da capacit8ncia. =sando o #erador de função para variar a frequ-ncia e visuali)ando o pico da sa6da com um oscilosc!pio" eu variei os valores dos capacitores at+ que o pico da resposta ressonante fosse a 0@k&). 1 capacitor final foi de @.@0uF. =ma ve) que o meu capacitor precisa ser um valor de mercado" a bobina que eu constru6 precisa ter uma indut8ncia maior que @u&.
1 pr!%imo est>#io era pro7etar o circuito anal!#ico. Eu usei o confi>vel c onfi>vel ,K$1$ LM@/ :eu 7> possuia v>rios desses em casatica do cartão
Desenvolvido por Rick &uan#.
,daptado para o portu#u-s por Eletronica.or#" com autori)ação do autor.
,ne%os FirmOare Meitor RFID Revisão / FirmOare Meitor RFID Revisão • •
PVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV
PVV PVV RFID reader section" #enerate 0@H&) carrier frequencJ PVV and decode t(e basic data stream PVV PVV Gritten bJ Rick &uan#" CopJri#(t :C< /@@ PVV Revision KKDD PVV Rev . /@@@A/W Initial release PVV Rev /. /@@@0@0 ,dd automatic card detect PVV PVV Command Functions PVV XX Uasic decode" binarJ data output PVV X/X Debu# capture" Bbit data output PVV XX Full capture and decode PVV XAX &e% test ec(o anJ (e% input PVV XX ,uto card detect mode PVV XX PVV PVV PVV L(is pro#ram is free softOareP Jou can redistribute it andor modifJ PVV it under t(e terms of t(e Y2= Yeneral $ublic Micense as publis(ed bJ PVV t(e Free 'oftOare FoundationP eit(er version / of t(e Micense" or PVV :at Jour option< anJ later version. PVV PVV L(is pro#ram is distributed in t(e (ope t(at it Oill be useful" PVV but GIL&1=L ,2 G,RR,2LP Oit(out even t(e implied OarrantJ of PVV KERC&,2L,UIMIL or FIL2E'' F1R , $,RLIC=M,R $=R$1'E. 'ee t(e PVV Y2= Yeneral $ublic Micense for more details. PVV PVV ou s(ould (ave received a copJ of t(e Y2= Yeneral $ublic Micense PVV alon# Oit( t(is pro#ramP if not" Orite to t(e Free 'oftOare PVV Foundation" Inc." 0W Lemple $lace" 'uite @" Uoston" K, @/@ =', PVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV PVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV PVV 21LE? Disable t(e GDL O(en debu##in# t(e code" (oOever" make sure PVV t(e GDL is enabled O(en puttin# t(e sJstem into lift time test PVV L(e timeout for GDL is about / seconds Oit( /B? prescaler PVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV include Zpf/B.inc[ \\confi# \&'\1'C \$GRLE\12
] \GDL\12 ] \M;$\1FF ] \U1DE2\12 ] \KCMRE\12 ]
PVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV PVV ;ariables LempG E9= @( P UitMocation E9= ( CounterU E9= /( 2e%tF'R E9= ( P CounterG E9= A(
UitCount MastUit;al Data@ Data Data/ Data DataA ^ero 'erData Lemp 1utput Counter LKRsample UinCnt Lo##le L(reeLrJ FCData@ FCData FCData/ FCData FCDataA GrittenUit
E9= E9= E9= E9= E9= E9= E9= E9=
0( ( ( B( W( a( /( b( E9=
E9= E9=
P ^ero is @%@@ c(
d( e( E9=
E9= E9= E9= E9=
f( @( ( ( A(
E9= E9= E9= E9= E9= E9=
P Final data output
0( ( ( B( W(
P First data captured
a(
_define _define _define _define _define _define _define _define
\$1,' $1RLU" \D1=L $1RLU" \HE $1RLU" 0 \UEE$$1RLU" A \$GK\1 $1RLU" \L`D $1RLU" / \R`D $1RLU" \=2= $1RLU" @
_define
Decision;al
P $oOer 12 ,uto 'tart P P HeJ #ood output P Ueeper output P $GK 0@k&) P =,RL P =,RL P =nused
dX@X P&ard decision" @ 0W cJcle" WB cJcle
PVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV PVV $ro#ram code (ere #oto 'tart 1RY A POaitin# for Z@@@A[ Pinterrupt vector P#oto Interrupt 1RY 0 PVVVVVVVVVVVVVVVVVVVVVVVVVVVVV 'trin#'tart? $GelcomeKs#? addOf $CM" F DL Gelcome DL &X@dX" &X@aX" &X@@X $CommandKs#? DL Command Error
D,L,
DL &X@dX" &X@aX" &X@@X $$arameterKs#? DL $arameter Error DL &X@dX" &X@aX" &X@@X $2o,ckKs#? DL Kissin# ,ck DL &X@dX" &X@aX" &X@@X 'trin#End? GelcomeKs# E9= @ CommandKs# E9= $CommandKs# 0 $arameterKs#E9= $$arameterKs# 0 P 'trin#s start 2o,ckKs# E9= $2o,ckKs# 0 &e%Lable? addOf $CM" F DL @/A0BW,UCDEF
PVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV PVVVVVVVVVVVVVVVVVVVV $ro#ram 'tarts (ere 'tart? PVVVVVVVVVVVVVVVVVVVVV 'etup GDL PVVVVVVVVVVVVVVVVVVVVVV 'ettin# up LKR@" used to decode F'H bcf \UEE$ clrOdt bsf 'L,L='" R$@ movlO bX@@@@X P$rescaler to GDL" ?/B movOf 1$LI12\REY clrOdt PVVVVVVVVVVVVVVVVVVVVV 'ettin# up environment movlO bX@@@@@@X P'erial port in too movOf LRI'U P'et port U I1 movlO bX@@@@@X movOf LRI', P'et port , I1 bcf 'L,L='" R$@ clrf $1RL, PVVVVVVVVVVVVVVVVVVVVVV Disable f/B specific features movlO bX@@@@@@X P'etup comparator movOf CKC12 PVVVVVVVVVVVVVVVVVVVVVV 'ettin# up $GK module for 0@H&) si#nal movlO bX@@@@@@X PEnable $GK module" dutJ / movOf CC$C12 movlO bX@@@@@@@X P=sin# source frequencJ /K&) movOf CC$RM movlO bX@@@@@@X P'ettin# up LKR/" $rescale ?A movOf L/C12 bsf 'L,L='" R$@ movlO bX@@@@@@@X movOf $R/ P'ettin# t(e period A
P 0 is t(e offset O(ere t(e
bcf 'L,L='" R$@ PVVVVVVVVVVVVVVVVVVVVVV 'etup =,RL bsf 'L,L='" R$@ movlO dX/X P0@@ for /K&) Clock" &i#( speed movOf '$URY PL(e onlJ rate Oit( loO mismatc( movlO bX@@@X P,sJnc Bbit &i#( speed movOf L`'L, bcf 'L,L='" R$@ movlO bX@@@@@X PEnable serial port movOf RC'L, clrf ^ero movlO GelcomeKs# PDisplaJ Oelcome strin# on startup call 'end'trin# P Debu# insert #oto 'kipDebu# movlO @a@( movOf F'R movlO bX@@@@@@X movOf I2DF incf F'R" F movlO bXX movOf I2DF incf F'R" F movlO bX@@X movOf I2DF incf F'R" F movlO bX@@@X movOf I2DF incf F'R" F movlO bX@@@@@@X movOf I2DF incf F'R" F movlO bX@@@@X movOf I2DF incf F'R" F movlO bX@@@X movOf I2DF incf F'R" F movlO bX@@@@@X movOf I2DF incf F'R" F #oto FD\DecodeEntrJ 'kipDebu#? P Gait for command GaitKore? btfsc \$1,' #oto ,utoDecode clrOdt btfsc RC'L," 1ERR
#oto ClearError btfss $IR" RCIF #oto GaitKore movfORCREY movOf 'erData movOf L`REY call ''pace movlO XX %orOf 'erData" G btfsc 'L,L='" ^ #oto ,ttempt'ample movlO X/X %orOf 'erData" G btfsc 'L,L='" ^ #oto Debu#'ample movlO XX %orOf 'erData" G btfsc 'L,L='" ^ #oto FullDecode movlO XAX %orOf 'erData" G btfsc 'L,L='" ^ #oto &e%Lest movlO X0X %orOf 'erData" G btfsc 'L,L='" ^ #oto UinLest movlO XX %orOf 'erData" G btfsc 'L,L='" ^ #oto ,utoDecode movlO XX %orOf 'erData" G btfsc 'L,L='" ^ #oto LestUeep movlO XBX %orOf 'erData" G btfsc 'L,L='" ^ #oto DummJ2oO DummJ2oO? movlO CommandKs# call 'end'trin# #oto GaitKore PVVVVVVVVVVVVVVVVVVVVV ClearError? movfORCREY movfORCREY
P'end it back out
PDecode command
P'tart a RFID sample
PDebu# run" output sampled data
PFullJ capture and decode data
PLestin# &E` routine
PLestin# Uin dump routine
P2o Debu# messa#e" auto card detection
PFor all command not in use P'end error command messa#e
Clear recevin# overrun error
bcf RC'L," CRE2 bsf RC'L," CRE2 #oto GaitKore P Commands e%ecution PVVVVVVVVVVVVVVVVVVVVVV Command ? ,ttempt'ample? PCommand ? 'ample RFID data" do @/A bits call CompC(eck PDummJ read once to setup condition movlO @a@( movOf F'R P=se F'R to store data movlO dXB@X PDo t(is for B@ bJtes movOf Counter 'ampleMoop? call CaptureUJte incf F'R" F P, bJte is full" move to t(e ne%t one decfs) Counter" F #oto 'ampleMoop P 'Oitc( memorJ bank movlO @/@( movOf F'R P=se F'R to store data movlO dXAX PDo t(is for A bJtes movOf Counter 'ampleMoop/? call CaptureUJte incf F'R" F decfs) Counter" F #oto 'ampleMoop/ P movlO dXB@X movOf Counter movlO @a@( movOf F'R
P, bJte is full" move to t(e ne%t one
Data is full" noO dump t(e data out PDo t(is for B@ bJtes
P=se F'R to access data
'ampleMoop@? movfOI2DF call 'endUin incf F'R" F decfs) Counter" F #oto 'ampleMoop@ P movlO dXAX movOf Counter movlO @/@( movOf F'R 'ampleMoop? movfOI2DF
'Oitc( bank PDo t(is for A bJtes
P=se F'R to access data
call incf decfs) #oto
'endUin F'R" F Counter" F 'ampleMoop
call #oto
2eOMine GaitKore
PVVVVVVVVVVVVVVVVVVVVVVV Command / Debu# mode Debu#'ample? call CompC(eck movlO @a@( movOf F'R movlO dXB@X movOf Counter
PCommand /? 'ample RFID data" debu# mode PDummJ read once to setup condition P=se F'R to store data PDo t(is for B@ bJtes
Debu#'Moop? call CompC(eck movfO LKRsample movOf I2DF incf F'R" F decfs) Counter" F #oto Debu#'Moop
P, bJte is full" move to t(e ne%t one
P 'Oitc( memorJ bank movlO @/@( movOf F'R P=se F'R to store data movlO dXAX PDo t(is for A bJtes movOf Counter Debu#'Moop/? call CompC(eck movfO LKRsample movOf I2DF incf F'R" F decfs) Counter" F #oto Debu#'Moop/ P movlO dXB@X movOf Counter movlO @a@( movOf F'R Debu#'Moop@? movfOI2DF call 'end&e% call 2eOMine
P, bJte is full" move to t(e ne%t one
Data is full" noO dump t(e data out PDo t(is for B@ bJtes
P=se F'R to access data
incf F'R" F decfs) Counter" F #oto Debu#'Moop@ P movlO dXAX movOf Counter movlO @/@( movOf F'R
'Oitc( bank PDo t(is for A bJtes
P=se F'R to access data
Debu#'Moop? movfOI2DF call 'end&e% call 2eOMine incf F'R" F decfs) Counter" F #oto Debu#'Moop
call #oto
2eOMine GaitKore
PVVVVVVVVVVVVVVVVVVVVVVV Command Full capture and decode FullDecode? PGait for start sequence" t(an start capture call CompC(eck PDummJ read once to setup condition call GaitLill'tart PGait for start movlO @a@( movOf F'R movlO dXB@X movOf Counter FDMoop? call incf decfs) #oto
CaptureUJte F'R" F Counter" F FDMoop
P movlO dXB@X movOf Counter movlO @a@( movOf F'R FDMoop@? movfOI2DF call 'endUin incf F'R" F decfs) Counter" F #oto FDMoop@
P=se F'R to store data PDo t(is for B@ bJtes
P, bJte is full" move to t(e ne%t one
Data is full" noO dump t(e data out PDo t(is for B@ bJtes
P=se F'R to access data
call 2eOMine FD\DecodeEntrJ? P Collaspe data bits movlO dXBX P'et up for bit read movOf UitMocation movlO @a@( movOf 2e%tF'R P 'tart e%traction clrf Data@ PClear data (older clrf Data clrf Data/ clrf Data clrf DataA clrf Lo##le FD\UitMoop^? call YetUitCount movfO UitCount movlO dX/@X subOf UitCount" G btfsc 'L,L='" C #oto FD\DoneDecode movlO dXX subOf UitCount" G btfss 'L,L='" C #oto FD\'end/bit movlO XVX call 'endC(ar call 'endC(ar bsf 'L,L='" C call Mon#'(ift call Mon#'(ift #oto FD\2e%tUit FD\'end/bit? movlO X\X call 'endC(ar bcf 'L,L='" C call Mon#'(ift FD\2e%tUit? movlO @ef( subOf 2e%tF'R" G btfss 'L,L='" C #oto FD\UitMoop^ call 2eOMine
P Uitcount 0 $ositive" Mooped alreadJ" 'L1$
P2e#ative" bits P$ositive" / bit
P2e%tF'R G P2e#ative" keep loopin# P$ositive" 2e%tF'R [ @%ef
P Final data output FD\DoneDecode?
call 2eOMine movfODataA call 'end&e% movfOData call 'end&e% movfOData/ call 'end&e% movfOData call 'end&e% movfOData@ call 'end&e% call #oto
2eOMine GaitKore
PVVVVVVVVVVVVVVVVVVVVVVV Command ? ,uto detection of card ,utoDecode? clrOdt movlO @( PL(ree trJs movOf L(reeLrJ ,D\Capture,#ain? clrf GrittenUit clrOdt call CompC(eck PDummJ read once to setup condition call GaitLill'tart PGait for start condition movlO @a@( movOf F'R movlO dXB@X movOf Counter ,DMoop? call incf decfs) #oto
CaptureUJte F'R" F Counter" F ,DMoop
P=se F'R to store data PDo t(is for B@ bJtes
P, bJte is full" move to t(e ne%t one
,D\DecodeEntrJ? P Collaspe data bits movlO dXBX P'et up for bit read movOf UitMocation movlO @a@( movOf 2e%tF'R P 'tart e%traction clrf Data@ PClear data (older clrf Data clrf Data/ clrf Data
clrf clrf
DataA Lo##le
,D\UitMoop^? call YetUitCount movlO dX/@X subOf UitCount" G btfsc 'L,L='" C #oto ,D\DoneDecode movlO dXX subOf UitCount" G btfss 'L,L='" C #oto ,D\'end/bit bsf 'L,L='" C call Mon#'(ift call Mon#'(ift #oto ,D\2e%tUit ,D\'end/bit? bcf 'L,L='" C call Mon#'(ift ,D\2e%tUit? incf GrittenUit" F movlO @ef( subOf 2e%tF'R" G btfss 'L,L='" C #oto ,D\UitMoop^ #oto
,utoDecode
P Uitcount 0 $ositive" 'tart condition a#ain" 'L1$
P2e#ative" bits P$ositive" / bit
P2e%tF'R G P2e#ative" keep loopin# P$ositive" 2e%tF'R [ @%ef" error PRestart...
P C(eck data is t(e same for t(ree times ,D\DoneDecode? movlO dX@X PError c(eck" if too manJ )ero bits" restart subOf UitCount" G btfsc 'L,L='" C #oto ,utoDecode PLoo manJ bits movlO (XAX subOf GrittenUit" G btfss 'L,L='" C #oto ,utoDecode
PC(eck number of bit Oritten" too little" restart
movlO (X00X subOf GrittenUit" G btfsc 'L,L='" C #oto ,utoDecode
PC(eck number of bit Oritten" too manJ" restart
movlO dXX %orOf L(reeLrJ" G btfss 'L,L='" ^
PFirst trJ indicator
#oto ,D\2otFirstLrJ movfOData@ movOf FCData@ movfOData movOf FCData movfOData/ movOf FCData/ movfOData movOf FCData movfODataA movOf FCDataA decf L(reeLrJ" F #oto ,D\Capture,#ain ,D\2otFirstLrJ? movfOData@ %orOf FCData@" G btfss 'L,L='" ^ #oto ,utoDecode P2ot matc(ed" restart movfOData %orOf FCData" G btfss 'L,L='" ^ #oto ,utoDecode P2ot matc(ed" restart movfOData/ %orOf FCData/" G btfss 'L,L='" ^ #oto ,utoDecode P2ot matc(ed" restart movfOData %orOf FCData" G btfss 'L,L='" ^ #oto ,utoDecode P2ot matc(ed" restart movfODataA %orOf FCDataA" G btfss 'L,L='" ^ #oto ,utoDecode P2ot matc(ed" restart decfs) L(reeLrJ" F #oto ,D\Capture,#ain P Final data output call 2eOMine movfODataA call 'end&e% movfOData call 'end&e% movfOData/ call 'end&e% movfOData call 'end&e% movfOData@ call 'end&e% call
2eOMine
call #oto
Ueep GaitKore
PVVVVVVVVVVVVVVVVVVVVVVV Command A"0 'erial debu# &e%Lest? call Rcv&e% movfO 1utput call 'end&e% call 2eOMine #oto GaitKore UinLest? call Rcv&e% movfO 1utput call 'endUin call 2eOMine #oto GaitKore LestUeep? call call #oto
Ueep 2eOMine GaitKore
PCommand A? &e% test
PCommand 0? Uin test
PCommand ? Lest beep
PVVVVVVVVVVVVVVVVVVVVVVVVVVVVV '=UR1=LI2E P P Mon#'(ift" '(ift bit of t(e data into Data@?A re#ister P '(ift onlJ bit per tOo calls P Input? C Mon#'(ift? btfss Lo##le" @ #oto Lo##le2ot'et rlf Data@" F rlf Data" F rlf Data/" F rlf Data" F rlf DataA" F bcf Lo##le" @ return Lo##le2ot'et? bsf return
Lo##le" @
P P CaptureUJte" Capture a sin#le bJte of data P 1utput? I2DF CaptureUJte?
call CompC(eck movlO Decision;al subOf LKRsample" G rlf I2DF" F
P&ard decision" @ 0W cJcle" WB cJcle P'tore t(e data into pointed address
call CompC(eck PDo t(is for B times to fill up a bJte movlO Decision;al subOf LKRsample" G rlf I2DF" F call CompC(eck movlO Decision;al subOf LKRsample" G rlf I2DF" F call CompC(eck movlO Decision;al subOf LKRsample" G rlf I2DF" F
call CompC(eck movlO Decision;al subOf LKRsample" G rlf I2DF" F call CompC(eck movlO Decision;al subOf LKRsample" G rlf I2DF" F call CompC(eck movlO Decision;al subOf LKRsample" G rlf I2DF" F call CompC(eck movlO Decision;al subOf LKRsample" G rlf I2DF" F return P P GaitLill'tart" Gait until t(e start sequence is detected P L(is is marked bJ /@ or more )eros GaitLill'tart? movlO dX/@X movOf CounterG
GL'\ne%t? clrOdt call CompC(eck movlO Decision;al subOf LKRsample" G btfsc 'L,L='" C PC(eck for a @ value #oto GaitLill'tart PIf " restart decfs) CounterG" F #oto GL'\ne%t PMoop until done return
P P CompC(eck" C(eck t(e comparator output and store t(e informtion in P 1utput? LKRsample CompC(eck? P$rocess? Moop until a transition" clear LKR@" POait till ne%t @ transition 'C'ampleM? btfsc CKC12" C1=L #oto 'C'ampleM 'C'ampleM/? PGas a loO" Oait for a (i#( btfss CKC12" C1=L #oto 'C'ampleM/ movfOLKR@ movOf LKRsample clrf LKR@ return
P'tore t(e result in LKRsample PClear LKR@ for t(e ne%t bit
P P YetUitCount" Count number of bits until t(e ne%t c(an#e P 1utput? UitCount P ,ddress? UitMocation" 2e%tF'R P =se? MastUit;al" UitCount" 2e%tF'R" UitMocation" LempG YetUitCount? clrf UitCount btfss MastUit;al" @ #oto YUC\lastbit@ P #oto YUC\lastbit PMast bit is a YUC\loop? call Yet2e%tUit btfss 'L,L='" ^ #oto YUC\done incf UitCount" F PContinue if value is a )ero #oto YUC\loop YUC\done? PDone if bit c(an#e to one bcf MastUit;al" @ return
YUC\lastbit@? PMast bit is a @ YUC\loop@? call Yet2e%tUit btfsc 'L,L='" ^ #oto YUC\done@ incf UitCount" F PContinue if value is a one #oto YUC\loop@ YUC\done@? PDone if bit c(an#e to one bsf MastUit;al" @ return P P Yet2e%tUit" Yet a bit from t(e buffer P 1utput? ^ P ,ddress? UitMocation" 2e%tF'R" UitMocation for M'U Yet2e%tUit? movfO 2e%tF'R movOf F'R movfO UitMocation movOf CounterU decfs) UitMocation" FPYo to t(e ne%t bit #oto Y2U\ne%t'tep movlO dXBX movOf UitMocation incf 2e%tF'R" F PRollover for t(e ne%t read Y2U\ne%t'tep? clrf LempG bsf 'L,L='" C Y2U\loop? rlf LempG" F PLempG contain bit mask decfs) CounterU" F #oto Y2U\loop movfO LempG andOf I2DF" G PResult in ^ return PVVVVVVVVVVVVVVVVVVVVVVVVVVVVV '=UR1=LI2E P P 'end&e%" 'end a sin#le bJte out of serial port" (e% format P Input? data stored in G 'end&e%? movOf Lemp sOapf Lemp" G andlO @@f( call &e%Lable &e%GaitMoop? btfss $IR" L`IF PGait till buffer is emptJ #oto &e%GaitMoop movOf L`REY
movf Lemp" G andlO @@f( call &e%Lable &e%GaitMoop/? btfss $IR" L`IF PGait till buffer is emptJ #oto &e%GaitMoop/ movOf L`REY return
P P 'endUin" 'end a sin#le bJte out of serial port" binarJ format P Input? data stored in G 'endUin? movOf Lemp movlO B( movOf UinCnt UinGaitMoop? btfss $IR" L`IF PGait till buffer is emptJ #oto UinGaitMoop movlO X@X btfsc Lemp" movlO XX movOf L`REY rlf Lemp" F decfs) UinCnt" F #oto UinGaitMoop return
P P Rcv&e%" Receive a sin#le bJte from serial port in (e% format P 1utput? data stored in 1utput Rcv&e%? btfss $IR" RCIF #oto Rcv&e% movfORCREY movOf 'erData movOf L`REY P 'end it back out movlO @( subOf 'erData" F movlO @( subOf 'erData" G btfsc 'L,L='" C #oto Metter RtnMetter?
PFG P $ositive means letter input
sOapf 'erData" G movOf 1utput Rcv&e%Moop? btfss $IR" RCIF #oto Rcv&e%Moop movfORCREY movOf 'erData movOf L`REY movlO @( subOf 'erData" F movlO @( subOf 'erData" G btfsc 'L,L='" C #oto Metter/ RtnMetter/? movfO'erData iorOf 1utput" F call ''pace return Metter? movlO @( subOf 'erData" F movlO @( subOf 'erData" G btfsc 'L,L='" C #oto MetterE #oto RtnMetter MetterE? movlO dX/X subOf 'erData" F #oto RtnMetter Metter/? movlO @( subOf 'erData" F movlO @( subOf 'erData" G btfsc 'L,L='" C #oto Metter/E #oto RtnMetter/ Metter/E? movlO dX/X subOf 'erData" F #oto RtnMetter/
P 'end it back out
PFG P $ositive means letter input
P $ositive means bad input
P $ositive means bad input
P P Mon#DelaJ" 0 cJcles" inscJcle //.0u' for BK() clock lon#\delaJ? movlO dX0X movOf Counter
lon#\delaJ\M? decfs) Counter" F #oto lon#\delaJ\M return P P 'end'trin#" send t(e strin# out to serial port P Input? 'trin# location in G 'end'trin#? movOf Counter 'endMoop? btfss $IR" L`IF PGait till buffer is emptJ #oto 'endMoop call 'trin#'tart iorOf ^ero" G btfsc 'L,L='" ^ P^ero is t(e end of strin# return movOf L`REY incf Counter" F movfO Counter #oto 'endMoop P P 2eOMine" send s neOline c(aracter into serial port P Input? 2one 2eOMine? btfss $IR" L`IF PGait till buffer is emptJ #oto 2eOMine movlO @d( movOf L`REY movlO @a( 2eOMineMoop? btfss $IR" L`IF PGait till buffer is emptJ #oto 2eOMineMoop movOf L`REY return P P 'pace" send a space c(aracter into serial port P Input? 2one ''pace? btfss $IR" L`IF PGait till buffer is emptJ #oto ''pace movlO X X movOf L`REY return P P 'endC(ar" send a c(aracter into serial port P Input? G
View more...
Comments
