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| Код |
;***************************************************************************
;* AVR Temper8 AT90S2313 version *
;* Reads up to eight Dallas DS1820/DS18S20 Temperature sensors connected *
;* to an AVR port bit. The temperature (degrees C, ASCII, + CRLF) is sent *
;* out the serial port when a Tn (where n is a single digit from 0 to 7) *
;* is received by the serial port. *
;* An R character returns a count of the devices found, plus a list of *
;* their ROM IDs *
;* Here's an example: *
;* command sent : r *
;* program returns: *
;* 4 *
;* 0800080007CC0010 *
;* C000080007728A10 *
;* 0D00080007455E10 *
;* 3300080007B60510 *
;* 0000000000000000 *
;* 0000000000000000 *
;* 0000000000000000 *
;* 0000000000000000 *
;* *
;* command sent: t1 *
;* program returns: *
;* +023.50C *
;* *
;* 1-Wire port bit: *
;* Port B bit 2 (PB2) -- The code turns on the pullup feature of the AVR *
;* port bit used. This is enough to enable the 1-Wire bus. *
;* The 4.7K pullup resistor required in most applications (see the DS18S20 *
;* data sheet) can also be used without changing the software. *
;* Acknowledgments *
;* This code was ported from my AT90S8515 program, 8515Temp8, which is *
;* in turn a port from my 68HC11 program, LCDTemper8 *
;* The ROMSrch (ROM Search) routine was ported from ML6805,a Public Domain *
;* assembly language example from Dallas Semiconductor. *
;* It was originally written for the 6805. I also used the code in *
;* The Dallas/Maxim Application Note 162: *
;* INTERFACING THE DS18X20/DS1822 1-WIRE TEMPERATURE SENSOR IN A *
;* MICRO-CONTROLLER ENVIRONMENT as a guide. *
;* I also borrowed from a few Atmel AVR application notes *
;* *
;* The DS1820 devices are read only after setup (to read their ROM codes) *
;* and during a temperature conversion request. *
;* Results are sent to the serial port *
;* FH 030111 First mod of AT90S8515 version *
;* FH 030112 Enabled the internal pullup resistor for Port B pin 2. The *
;* typical 4.7K pullup resistor on the DS line no longer needed *
;* *
;* Frank Henriquez [email protected] http://www.bol.ucla.edu/~frank/ *
;* Please do not delete any of the text in this comment box. *
;* Please do not redistribute modified versions of this code *
;***************************************************************************
.include "2313def.inc"
;**********************************************
;* Equates *
;**********************************************
.equ clock = 8000000 ;clock frequency
.equ baudrate = 9600 ;choose a baudrate
.equ baudconstant= (clock/(16*baudrate))-1
.equ STACKTOP = RAMEND - 100
;**********************************************
;* Registers used *
;**********************************************
.def Done = r10 ;used in GetROMs
.def ROMCount = r11 ;number of devices found
.def SaveSREG = r12 ;used in Delay
.def BitNum = r13 ;used in ROMsrch
.def LastDis = r14 ;used in ROMsrch
.def LasDisCpy = r15 ;used in ROMsrch
.def AReg = r16 ;working reg, like the 68HC11 A register
.def BReg = r17 ;working reg, like the 68HC11 B register
.def ScratchL = r18
.def ScratchH = r19
.def ByteCount = r20 ;used in ShowROM
.def Count8 = r21
.def DelayVal = r22
;**********************************************
;* DS1820 Command bytes *
;**********************************************
.equ ReadROM = $33
.equ MatchROM = $55
.equ SkipROM = $cc
.equ SearchROM = $f0
.equ SearchAlarm = $ec
.equ ConvertTemp = $44
.equ CpyScratch = $48
.equ WrScratch = $4e
.equ RdScratch = $be
.equ RecallEE = $b8
.equ ReadPS = $84
;**********************************************
;* The following delay constants are based on *
;* an 8MHZ clock (CLK) *
;* times are not exact. *
;**********************************************
.equ d250us = 6 ;250us CLK/8
.equ d100us = $9c ;70us CLK/8
.equ d44us = $d4 ;44us CLK/8
.equ d15us = $f2 ;14us CLK/8
.equ d2us = $fe ;2us CLK/8
.equ TSTOP =0 ;Stop Timer/Counter
.equ TCK1 =1 ;Timer/Counter runs from CK
.equ TCK8 =2 ;Timer/Counter runs from CK / 8
.equ TCK64 =3 ;Timer/Counter runs from CK / 64
.equ TCK256 =4 ;Timer/Counter runs from CK / 256
.equ TCK1024 =5 ;Timer/Counter runs from CK / 1024
.equ TEXF =6 ;Timer/Counter runs from external falling edge
.equ TEXR =7 ;Timer/Counter runs from external rising edge
.equ DSBus =2 ;PORTB bit used for the 1-wire bus
;**********************************************
;* 100 bytes of internal data RAM are used by *
;* the program *
;**********************************************
.dseg
.org RAMEND - 99
Buffer: .byte 16
;**********************************************
;* 9 bytes below are the register contents *
;* of the last DS18S20 read *
;**********************************************
TempLSB: .byte 1
TempMSB: .byte 1
THUB1: .byte 1
TLUB2: .byte 1
Res1: .byte 1
Res2: .byte 1
CountRem: .byte 1
CntPerC: .byte 1
CRC: .byte 1
ExtTemp: .byte 1
romoff: .byte 2 ;Pointer to Sensor address
romdta: .byte 8 ;ROM address of urrent device
Sensor0: .byte 8 ;DS1820 sensor 0 ID #
Sensor1: .byte 8 ;DS1820 sensor 1 ID #
Sensor2: .byte 8 ;DS1820 sensor 2 ID #
Sensor3: .byte 8 ;DS1820 sensor 3 ID #
Sensor4: .byte 8 ;DS1820 sensor 4 ID #
Sensor5: .byte 8 ;DS1820 sensor 5 ID #
Sensor6: .byte 8 ;DS1820 sensor 6 ID #
Sensor7: .byte 8 ;DS1820 sensor 7 ID #
.cseg
.org $000 ;Reset Vector
rjmp Reset
;Interrupt vectors
.org INT0addr ;External Interrupt0 Vector
reti
.org INT1addr ;External Interrupt1 Vector
reti
.org ICP1addr ;Input Capture1 Interrupt Vector
reti
.org OC1addr ;Output Compare1 Interrupt Vector Address
reti
.org OVF1addr ;Overflow1 Interrupt Vector
reti
.org OVF0addr ;Overflow0 Interrupt Vector
rjmp Tim0int
.org URXCaddr ;UART Receive Complete Interrupt Vector
rjmp ParseIn
.org UDREaddr ;UART Data Register Empty Interrupt Vector
reti
.org UTXCaddr ;UART Transmit Complete Interrupt Vector
reti
.org ACIaddr ;Analog Comparator Interrupt Vector
reti
Reset:
ldi AReg,low(STACKTOP)
out SPL,AReg ;set low byte for stack pointer
rcall Setup ;set up DS1820 bits, Serial I/O
RPLoop:
rjmp RPLoop ;wait here until something interesting happens
;**********************************************
;* Setup *
;* Initialize the 1-Wire bus & serial port *
;**********************************************
Setup:
;** serial port setup **
ldi AReg,baudconstant
out UBRR,AReg ;load baudrate
;**enable UART receiver & transmitter and IRQ on serial in:
ldi AReg, (1<<RXEN)|(1<<TXEN)|(1<<RXCIE)
out UCR,AReg
ldi AReg,TSTOP ;Timer 0 off (just in case)
out TCCR0,AReg ;Stop timer
ldi AReg,0b00000010 ;Enable Timer 0 interrupt
out TIMSK,AReg
sei ;enable interrupts
rcall GetROMS
ret
;**********************************************
;* DS1820 Routines *
;**********************************************
;**********************************************
;* DSReset *
;* Sends a reset pulse to all devices. *
;* Returns carry set if devices present. *
;* Returns carry clear if no devices present. *
;**********************************************
DSReset:
sbi DDRB,DSBus ;DDRB bit 2 = 1 = output
cbi PORTB,DSBus ;set 1-wire bus low
ldi DelayVal,d250us
rcall Delay
rcall Delay ;Wait 250us x 2 = 500 us
cbi DDRB,DSBus ;Switch DS bus bit to input (pulled up high)
sbi PORTB,DSBus ;turn on pullup
ldi DelayVal,d100us
rcall Delay ;Wait 100 us for the DS1820 to respond
clc ;exit with carry clear if no device
sbis PINB,DSBus ;skip next if port B bit 2=1
sec ;bit was clear (=0) so set carry flag
ldi DelayVal,d250us
rcall Delay
rcall Delay ;Wait 500 us
ret
;**********************************************
;* GetBit *
;* Carry holds the bit from the DS1820 bus *
;**********************************************
GetBit:
ldi DelayVal,d2us ;wait for the 1820 data
sbi DDRB,DSBus ;DDRB bit 2 = 1 = output
cbi PORTB,DSBus ;set 1-wire bus low
rcall Delay
cbi DDRB,DSBus ;DDRB bit 2 = 0 = input
sbi PORTB,DSBus ;turn on pullup
ldi DelayVal,d15us ;wait 15us for the 1820 data
rcall Delay
clc ;assume 1-Wire bus is low
sbic PINB,DSBus
sec ;1-Wire bus is high, so set carry flag
ldi DelayVal,d44us
rcall Delay
ret
;**********************************************
;* Write bit in CC to DS bus *
;**********************************************
PutBit:
sbi DDRB,DSBus ;DDRB bit 2 = 1 = output
cbi PORTB,DSBus ;Pull Port B, bit 2 low
ldi DelayVal,d15us ;wait for the 1820 sample window
rcall Delay
brcc Put0 ;if carry = 0, send a 0
cbi DDRB,DSBus ;otherwise, send a 1
sbi PORTB,DSBus ;turn on pullup
Put0:
ldi DelayVal,d44us ;load 44us delay in delay register
rcall Delay ;and wait
cbi DDRB,DSBus ;this signals the end of a write 0
sbi PORTB,DSBus ;turn on pullup
ldi DelayVal,d2us ;let the DS1820 rest & digest
rcall Delay
ret
;**********************************************
;* GetByte *
;* AReg returns the byte from the DS1820 bus *
;**********************************************
GetByte:
ldi BReg,8 ;bit count
clr AReg
NxtBit:
rcall GetBit
ror AReg ;shift carry bit into AReg
dec BReg
brne NxtBit ;repeat for all 8 bits
ret
;**********************************************
;* PutByte *
;* data in AReg *
;**********************************************
PutByte:
ldi BReg,8 ;bit counter
ShiftB:
lsr AReg ;shift bits in AReg into carry
rcall PutBit
NextB:
dec BReg
brne ShiftB
ret
;**********************************************
;* Search for devices on DS bus *
;* Based on Dallas Semiconductor's ML6805 *
;* code. *
;**********************************************
ROM1st:
ldi AReg,$41 ;Point Rom Search to top (1st part).
mov LastDis,AReg
rcall ROMSrch
ret
ROMSrch:
push XL
push XH
rcall DSReset ;Reset 1-wire bus.
brcs r_look
rjmp NoDev
r_look:
ldi AReg,$40 ;Prepare to find 64 bits of ROM data.
mov BitNum,AReg
ldi Count8,8 ;Initial value for eight counter.
mov LasDisCpy, LastDis ;Save copy of last dis. from last search.
ldi XL,low(romdta)
ldi XH,high(romdta) ;point to 1st byte of ROM data
sts romoff,XL ;buffer in rombuff.
sts romoff+1,XH
ldi AReg,SearchROM ;Get ROM search command in AReg.
rcall PutByte ;Send ROM search command to DOW bus.
NxtRBit:
clr AReg
clr BReg
rcall GetBit ;1st read time slot.
rol BReg ;reg BReg, bit0 has first result
rcall GetBit ;2nd read time slot.
rol AReg
cpi BReg,1 ;Was the first bit received 1?
brne no_or ;Branch if it wasn't
ori AReg,2 ;Set bit 1 in AReg
no_or:
cpi AReg,3 ;See if error condition occurred.
breq NoDev ;Abort if error.
cpi AReg,0 ;Was there a disagreement on bus.
brne nosave ;Branch if there wasn't.
cp LasDisCpy,BitNum ;Compare last dis to current position.
brne lwhere ;If its not equal look some more.
ldi AReg,1 ;We've been on this path and sent a 0.
rjmp wrtBit ;now lets send a 1.
lwhere:
brcs sLstBit ;Stay on previous path.
clr AReg ;Past last dis. fall to the right.
rjmp savedis ;Send 0 to bus.
sLstBit:
lds XL,romoff ;Get offset of ROM data buffer in
lds XH,romoff+1
ld AReg,X ;index register, and byte in AReg.
andi AReg,1 ;Isolate lsb of AReg.
cpi AReg,1 ;See if it was a 1.
breq wrtBit ;Don't save as dis position if so.
savedis:
mov LastDis,BitNum ;Get current position in x register.
;Save current last disagreement pos.
rjmp wrtBit ;Send the write bit time slot.
nosave:
ldi BReg,1
eor AReg,BReg ;Flip lsb of AReg.
wrtBit:
andi AReg,1 ;Isolate lsb of AReg
mov BReg,AReg
lsr BReg
rcall PutBit ;Send lsb of AReg to 1-wire bus.
lds XL,romoff
lds XH,romoff+1 ;Get offset into ROM data buffer.
ld AReg,X ;Get previous val of rombyte.
ror AReg ;Get ROM bit in MSB of rombyte.
st X,AReg ;Store new byte value & point to next byte
dec Count8 ;Decrement byte counter.
brne bnfull ;Branch if we don't have full byte.
adiw XH:XL,1 ;increment x
sts romoff,XL ;buffer in rombuff.
sts romoff+1,XH
ldi Count8,8 ;reload the eight counter.
bnfull:
dec BitNum ;Decrement 64 bit counter.
brne NxtRBit ;Go get next rom bit.
cp LasDisCpy,LastDis ;Compare to last dis. copy
brne MoDows ;If not equal clear AReg.
ldi AReg,$41 ;Point ROM search algorithm back
mov LastDis,AReg ;to first part.
ldi AReg,1 ;Indicate this was last part on bus.
rjmp lastdow ;Skip the clra statement and leave.
MoDows:
clr AReg ;Indicate that more parts are on bus.
lastdow:
sec ;Indicate success.
rjmp DevFnd ;Skip clear carry stuff.
NoDev:
clc ;Indicate failure.
DevFnd:
pop XH
pop XL
ret
;**********************************************
;* GetROMS *
;* Looks for up to 8 DS1820s, reads their *
;* 64 bit ROM codes and saves them in memory *
;**********************************************
GetROMS:
clr AReg
clr ROMCount ;clear out ROMCount
clr Done ;clear Done flag
ldi YH,high(romdta)
ldi YL,low(romdta) ;Y points to romdta buffer
ClrOut:
st Y+,AReg ;clear out the ROM ID storage area
cpi YL,low(Sensor7+8)
brcs ClrOut
LookROM:
rcall DSReset ;Reset 1-wire bus
;*** to send out the list of ROMs found, uncomment the line below
brcc SetExit ;Abort if no presence detect
;*** to NOT send out the list of ROMs found, uncomment the line below
; brcc SetExit2 ;Abort if no presence detect
rcall ROM1st ;look for the first ROM
mov ScratchL,AReg
brcc SetExit ;if AReg = 0 then there are more devices
ldi XH,high(Sensor0)
ldi XL,low(Sensor0) ;X points to first device ID
rjmp MR0 ;process them & exit
LR1:
rcall ROMSrch ;look for other devices
mov ScratchL,AReg
breq MR0 ;if AReg = 0 then there are more devices
inc Done
MR0:
ldi YH,high(romdta+8)
ldi YL,low(romdta+8) ;Y points to ROM just read
MoveROM:
ld AReg,-Y ;move byte from romdta
st X+,AReg ;to SensorX
cpi YL,low(romdta) ;move all 8 bytes
brne MoveROM ;of the ROM ID
inc ROMCount ;increment the ROM counter
tst ScratchL ;repeat until the last device found
breq MR2
inc Done
MR2:
tst Done
brne SetExit
cpi XL,low(Sensor7+8) ;or until the end of the ROM
brcs LR1 ;storage area is reached
SetExit:
rcall ShowROM ;then Display the ROM IDs
SetExit2:
ret
;**********************************************
;* ShowROM *
;* Converts data in the Sensor area to ASCII *
;* hex and send them out the serial port. *
;**********************************************
ShowROM:
ldi XL,low(Sensor0) ;X points to Sensor ID area
ldi XH,high(Sensor0)
SRLoop:
ldi YL,low(Buffer) ;Y points to ASCII data buffer
ldi YH,high(Buffer)
ldi ByteCount,8
ROMHex:
ld AReg,X+ ;convert 8 bytes to 16 ASCII Hex
rcall Put1Hex ;characters
dec ByteCount
brne ROMHex
ldi YL,low(Buffer)
ldi YH,high(Buffer)
ROMOut:
ld AReg,Y+ ;send characters in the buffer
rcall SerOut ;to the serial port
cpi YL,low(Buffer+16)
brcs ROMOut
clr AReg
st Y,AReg
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