multiple DS1822s Cant get the serial numbers?
technoob
Posts: 21
Hi all,
Ive installed this code.· I copied it from a Nuts and Volts from a post back in 2001.· I m using a BS2P40.·
·I have the pin pulled up with a 4.61k ohm resistor.· This code gets stuck at ""Searching for 1-Wire devices...",
Im either stuck at 00 in the reads and its looping into eternity ·becuase my 4.7 isnt wired right or Im so noobish Im missing the obvious.
this code confuses me and I have spend hours studying it.· Im quite the begginer but I need this to work for my application.·
please help.···
Randy "technoob"
' {$STAMP BS2p}
' {$PBASIC 2.5}
·' Program Listing 72.1
' Nuts & Volts - Stamp Applications, April 2001
'
' ----[noparse][[/noparse] Title ]
'
' File...... SRCHDEMO.BSP
' Purpose... Demonstrates Dallas 1-Wire Search Algorithm
' Author.... Jon Williams
' E-mail.... jonwms@aol.com
' Started... 27 FEB 2001
' Updated... 05 MAR 2001
' ----[noparse][[/noparse] Program Description ]
'
' The purpose of this program is to demonstrate the use of external
' program slots to hold code code or subroutines. When first downloaded
' to the BS2p, the number of Dallas 1-Wire devices is unknown (flag value
' of $FF). This program reads that flag and if it is $FF, the search
' program slot is called to conduct the search. Search results are
' written directly to the this program's EE (thanks to the BS2p STORE
' function).
'
' When the search is complete, a list of all found devices is displayed
' in a DEBUG window.
' ----[noparse][[/noparse] Revision History ]
'
' 28 FEB 2001 - Version 1 complete and tested
' ----[noparse][[/noparse] I/O Definitions ]
'
OWpin····· CON·········· 0········· ' 1-Wire bus
' ----[noparse][[/noparse] Constants ]
'
SearchPgm· CON·········· 1···· ' search program slot
NamesPgm·· CON·········· 2···· ' DalSemi OW device names
····· ' 1-Wire Support
'
OW_FERst·· CON %0001············ ' Front-End Reset
OW_BERst·· CON %0010············ ' Back-End Reset
OW_BitMode CON %0100
OW_HighSpd CON %1000
ReadROM·· CON $33··············· ' read ID, serial num, CRC
MatchROM· CON $55·············· ' look for specific device
SkipROM·· CON $CC··············· ' skip ROM (one device)
SearchROM CON $F0············· ' search
' ----[noparse][[/noparse] Variables ]
'
thisSlot·· VAR Nib··············· ' this program's slot (0 - 7)
devices··· VAR Byte··············· ' 1-Wire devices found
addr······ VAR Word·················· ' EE address of device SN
offset···· VAR Nib················· ' offset byte of device SN
idx······· VAR Byte··················· ' loop counter
dByte····· VAR Byte················· ' data byte
devType··· VAR Byte··············· ' device type (first byte of SN)
devName··· VAR Byte··············· ' device identifier
strPtr···· VAR Word················ ' string pointer
char······ VAR Byte·················· ' string character to print
crcErrors· VAR Byte·············· ' indicates problems with search
tempROM··· VAR Byte(8)············· ' data from 1-Wire device
crcVal···· VAR Byte················· ' CRC of returned data
' ----[noparse][[/noparse] EEPROM Data ]
'
Num_OW· DATA $FF················ ' number of 1-Wire devices
OW_Data DATA 0(80)············· ' space for 10 1-Wire SN's
' ----[noparse][[/noparse] Initialization ]
'
Initialize:
READ Num_OW,dByte·············· ' ROM codes present?
IF (dByte < $FF) THEN Main····· ' yes, run this program
DEBUG CLS
PAUSE 5
DEBUG "Searching for 1-Wire devices...",CR
GET 127,thisSlot··············· ' get this pgm slot #
PUT 126,thisSlot··············· ' save it
PUT 125,OWpin·················· ' save OW I/O
PUT 124,OW_Data················ ' save data storage start
PUT 123,0······················ ' clear CRC errors
RUN SearchPgm·················· ' run the search program
' ----[noparse][[/noparse] Main Code ]
Main:
GET 123,crcErrors
IF (crcErrors = 0) THEN ShowDevices
DEBUG "Warning: CRC errors during search.",CR
ShowDevices:
READ Num_OW,devices·············· ' get number of devices
DEBUG CR,DEC devices," device"
IF (devices = 1) THEN SkipEss
DEBUG "s"
SkipEss:
DEBUG " present.",CR
IF devices = 0 THEN Done
FOR idx = 1 TO devices··········· ' display each one
DEBUG CR, DEC2 idx," : "
addr = 8 * (idx - 1) + OW_Data··· ' calculate device address
STORE thisSlot··················· ' point to local EEPROM
FOR offset = 0 TO 7·············· ' eight bytes per device
READ (addr + offset),dByte······· ' read it from EEPROM
DEBUG HEX2 dByte················· ' show it
NEXT
READ addr,devType················ ' get device type
GOSUB DisplayDeviceType·········· ' display it
NEXT
Done:
DEBUG CR
END
' ----[noparse][[/noparse] Subroutines ]
'
' This subroutine is used to display the part number and description of
' a connected device. The text data and pointers to it are stored in the
' EE of a different program slot.
DisplayDeviceType:
DEBUG " -> "
addr = devType * 2 + $600·········· ' calulate string pointer addr
STORE NamesPgm····················· ' point to names EEPROM
READ addr,strPtr.LOWBYTE··········· ' get the string location
READ addr+1,strPtr.HIGHBYTE
ReadAChar:
READ strPtr,char··················· ' read character from string
IF (char = 0) THEN DevTypeDone····· ' at end? (0 = Yes)
DEBUG char························· ' no, print the char
strPtr = strPtr + 1················ ' point to next char
GOTO ReadAChar
DevTypeDone:
RETURN
Ive installed this code.· I copied it from a Nuts and Volts from a post back in 2001.· I m using a BS2P40.·
·I have the pin pulled up with a 4.61k ohm resistor.· This code gets stuck at ""Searching for 1-Wire devices...",
Im either stuck at 00 in the reads and its looping into eternity ·becuase my 4.7 isnt wired right or Im so noobish Im missing the obvious.
this code confuses me and I have spend hours studying it.· Im quite the begginer but I need this to work for my application.·
please help.···
Randy "technoob"
' {$STAMP BS2p}
' {$PBASIC 2.5}
·' Program Listing 72.1
' Nuts & Volts - Stamp Applications, April 2001
'
' ----[noparse][[/noparse] Title ]
'
' File...... SRCHDEMO.BSP
' Purpose... Demonstrates Dallas 1-Wire Search Algorithm
' Author.... Jon Williams
' E-mail.... jonwms@aol.com
' Started... 27 FEB 2001
' Updated... 05 MAR 2001
' ----[noparse][[/noparse] Program Description ]
'
' The purpose of this program is to demonstrate the use of external
' program slots to hold code code or subroutines. When first downloaded
' to the BS2p, the number of Dallas 1-Wire devices is unknown (flag value
' of $FF). This program reads that flag and if it is $FF, the search
' program slot is called to conduct the search. Search results are
' written directly to the this program's EE (thanks to the BS2p STORE
' function).
'
' When the search is complete, a list of all found devices is displayed
' in a DEBUG window.
' ----[noparse][[/noparse] Revision History ]
'
' 28 FEB 2001 - Version 1 complete and tested
' ----[noparse][[/noparse] I/O Definitions ]
'
OWpin····· CON·········· 0········· ' 1-Wire bus
' ----[noparse][[/noparse] Constants ]
'
SearchPgm· CON·········· 1···· ' search program slot
NamesPgm·· CON·········· 2···· ' DalSemi OW device names
····· ' 1-Wire Support
'
OW_FERst·· CON %0001············ ' Front-End Reset
OW_BERst·· CON %0010············ ' Back-End Reset
OW_BitMode CON %0100
OW_HighSpd CON %1000
ReadROM·· CON $33··············· ' read ID, serial num, CRC
MatchROM· CON $55·············· ' look for specific device
SkipROM·· CON $CC··············· ' skip ROM (one device)
SearchROM CON $F0············· ' search
' ----[noparse][[/noparse] Variables ]
'
thisSlot·· VAR Nib··············· ' this program's slot (0 - 7)
devices··· VAR Byte··············· ' 1-Wire devices found
addr······ VAR Word·················· ' EE address of device SN
offset···· VAR Nib················· ' offset byte of device SN
idx······· VAR Byte··················· ' loop counter
dByte····· VAR Byte················· ' data byte
devType··· VAR Byte··············· ' device type (first byte of SN)
devName··· VAR Byte··············· ' device identifier
strPtr···· VAR Word················ ' string pointer
char······ VAR Byte·················· ' string character to print
crcErrors· VAR Byte·············· ' indicates problems with search
tempROM··· VAR Byte(8)············· ' data from 1-Wire device
crcVal···· VAR Byte················· ' CRC of returned data
' ----[noparse][[/noparse] EEPROM Data ]
'
Num_OW· DATA $FF················ ' number of 1-Wire devices
OW_Data DATA 0(80)············· ' space for 10 1-Wire SN's
' ----[noparse][[/noparse] Initialization ]
'
Initialize:
READ Num_OW,dByte·············· ' ROM codes present?
IF (dByte < $FF) THEN Main····· ' yes, run this program
DEBUG CLS
PAUSE 5
DEBUG "Searching for 1-Wire devices...",CR
GET 127,thisSlot··············· ' get this pgm slot #
PUT 126,thisSlot··············· ' save it
PUT 125,OWpin·················· ' save OW I/O
PUT 124,OW_Data················ ' save data storage start
PUT 123,0······················ ' clear CRC errors
RUN SearchPgm·················· ' run the search program
' ----[noparse][[/noparse] Main Code ]
Main:
GET 123,crcErrors
IF (crcErrors = 0) THEN ShowDevices
DEBUG "Warning: CRC errors during search.",CR
ShowDevices:
READ Num_OW,devices·············· ' get number of devices
DEBUG CR,DEC devices," device"
IF (devices = 1) THEN SkipEss
DEBUG "s"
SkipEss:
DEBUG " present.",CR
IF devices = 0 THEN Done
FOR idx = 1 TO devices··········· ' display each one
DEBUG CR, DEC2 idx," : "
addr = 8 * (idx - 1) + OW_Data··· ' calculate device address
STORE thisSlot··················· ' point to local EEPROM
FOR offset = 0 TO 7·············· ' eight bytes per device
READ (addr + offset),dByte······· ' read it from EEPROM
DEBUG HEX2 dByte················· ' show it
NEXT
READ addr,devType················ ' get device type
GOSUB DisplayDeviceType·········· ' display it
NEXT
Done:
DEBUG CR
END
' ----[noparse][[/noparse] Subroutines ]
'
' This subroutine is used to display the part number and description of
' a connected device. The text data and pointers to it are stored in the
' EE of a different program slot.
DisplayDeviceType:
DEBUG " -> "
addr = devType * 2 + $600·········· ' calulate string pointer addr
STORE NamesPgm····················· ' point to names EEPROM
READ addr,strPtr.LOWBYTE··········· ' get the string location
READ addr+1,strPtr.HIGHBYTE
ReadAChar:
READ strPtr,char··················· ' read character from string
IF (char = 0) THEN DevTypeDone····· ' at end? (0 = Yes)
DEBUG char························· ' no, print the char
strPtr = strPtr + 1················ ' point to next char
GOTO ReadAChar
DevTypeDone:
RETURN
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Dave
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Dave Andreae
Parallax Tech Support