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program trouble

studentstudent Posts: 12
edited 2004-11-29 22:10 in BASIC Stamp
I am having trouble with displaying the temperature on the LCD (exp.#28). The DS1620 circuit works and shows with DEBUG, so I think the problem is with my code. My last try is below. Could you please help me with this. Thanks!

Regards,
Stu


' {$STAMP BS2}
' {$PBASIC 2.5}
'
' ==============================================================================

'
' Program Description
'
' This program measures temperature using the Dallas Semiconductor DS1620
' temperature sensor and displays the results in fahrenheit.

'
' I/O Definitions
'
DQ············· CON···· 0·················· ' DS1620.1 (data I/O)
Clock·········· CON···· 1··················· ' DS1620.2
Reset·········· CON···· 2···················· ' DS1620.3
E·············· CON···· 8···················· ' LCD Enable pin· (1 = enabled)
RS············· CON···· 3······················ ' Register Select (1 = char)
'
' Constants
'
ClrLCD········· CON· $01···················· ' clear the LCD
CrsrHm········· CON· $02····················· ' move cursor to home position
DispLf········· CON· $18······················ ' shift displayed chars left
DispRt········· CON· $1C······················· ' shift displayed chars right
DDRam·········· CON·· $80····················· ' Display Data RAM control
CGRam·········· CON· $40····················· ' Custom character RAM
Line1·········· CON· $80···················· ' DDRAM address of line 1
Line2·········· CON· $C0··················· ' DDRAM address of line 2
RdTmp·········· CON···· $AA···················· ' read temperature
WrHi··········· CON···· $01····················· ' write TH (high temp)
WrLo··········· CON···· $02······················ ' write TL (low temp)
RdHi··········· CON···· $A1······················· ' read TH
RdLo··········· CON···· $A2······················ ' read TL
StartC········· CON···· $EE····················· ' start conversion
StopC·········· CON···· $22···················· ' stop conversion
WrCfg·········· CON···· $0C··················· ' write config register
RdCfg·········· CON···· $AC·················· ' read config register
'
' Variables
'
tempIn········· VAR···· Word··················· ' raw temperature
sign··········· VAR···· tempIn.BIT8············ ' 1 = negative temperature
tSign·········· VAR···· Bit
tempC·········· VAR···· Word··················· ' Celsius
tempF·········· VAR···· Word··················· ' Fahrenheit
LCDout········· VAR···· OUTB··········· ' 4-bit LCD data
char··········· VAR···· Byte··········· ' character sent to LCD

'
' DATA statements
Msg· DATA· "Present Temperature = "

'
' Initialization
'
Initialize:
·DIRS = %1000000111111000··········· ' setup pins
· GOSUB LCDinit···················· ' initialize LCD for 4-bit mode
· HIGH Reset··································· ' alert the DS1620
· SHIFTOUT DQ, Clock, LSBFIRST, [noparse][[/noparse]WrCfg, %10]···· ' use with CPU; free-run
· LOW Reset
· PAUSE 10
· HIGH Reset
· SHIFTOUT DQ, Clock, LSBFIRST, [noparse][[/noparse]StartC]······· ' start conversions
· LOW Reset
· char = DDRAM


'
' Program Code
'
Main:
· GOSUB Get_Temperature························ ' read the DS1620
· DEBUG HOME
· DEBUG "<<<DS1620>>>·· ", CR
· DEBUG SDEC tempC, " C··· ", CR
· DEBUG SDEC tempF, " F··· ", CR
· GOSUB· LCDcommand
· READ (Msg + tempF), char
· GOSUB· LCDwrite
·· PAUSE 1000·································· ' pause between readings
· GOTO Main

'
' Subroutines
'
Get_Temperature:
· HIGH Reset··································· ' alert the DS1620
· SHIFTOUT DQ, Clock, LSBFIRST, [noparse][[/noparse]RdTmp]········· ' give command to read temp
· SHIFTIN DQ, Clock, LSBPRE, [noparse][[/noparse]tempIn\9]·········· ' read it in
· LOW Reset······································· ' release the DS1620
· tSign = sign································· ' save sign bit
· tempIn = tempIn / 2·························· ' round to whole degrees
· IF (tSign = 0) THEN No_Neg1
· tempIn = tempIn | 123························ ' extend sign bits for negative
No_Neg1:
· tempC = tempIn······························· ' save Celsius value
· tempIn = tempIn */ $01CC······················ ' multiply by 1.8
· IF (tSign = 0) THEN No_Neg2···················· ' if negative, extend sign bits
· tempIn = tempIn | 123
No_Neg2:
· tempIn = tempIn + 32························· ' finish C -> F conversion
· tempF = tempIn······························· ' save Fahrenheit value
· RETURN
·· LCDinit:
· PAUSE 500················· ' let the LCD settle
· LCDout = %0011·············· ' 8-bit mode
· PULSOUT E,1
· PAUSE 5
· PULSOUT E,1
· PULSOUT E,1
· LCDout = %0010·············· ' 4-bit mode
· PULSOUT E,1
· char = %00101000····················· ' multi-line mode
· GOSUB LCDcommand
· char = %00001100··········· ' disp on, crsr off, blink off
· GOSUB LCDcommand
· char = %00000110··········· ' inc crsr, no disp shift
· GOSUB LCDcommand
· RETURN
· LCDcommand:
·· LOW RS················· ' enter command mode
·· RETURN
· LCDwrite:
· LCDout = char.HIGHNIB········ ' output high nibble
· PULSOUT E,1·············· ' strobe the Enable line
· LCDout = char.LOWNIB········ ' output low nibble
· PULSOUT E,1
· HIGH RS················· ' return to character mode
· RETURN

Comments

  • Jon WilliamsJon Williams Posts: 6,491
    edited 2004-11-29 19:17
    You must convert your data manually before sending it to the LCD -- unless you upgrade to a BS2p or BS2pe which have LCDOUT commands that can use the DEC modifiers that you have successfully used with DEBUG.

    This will give you an idea. After positioning the LCD cursor, you can use this routine to put "tempRaw" into the LCD:

    Show_TempLCD: 
  IF (tempRaw.BIT15 = 1) THEN          ' check sign bit 
    char = "-"                         ' - for negative temp
  ELSE 
    char = " "                         ' blank for positive temp
  ENDIF 
  GOSUB LCDwrite                       ' write sign character
  tempRaw = ABS tempRaw                ' convert tempt to absolute value
  FOR idx = 2 TO 0                     ' loop through three digits
    char = tempRaw DIG idx + "0"       ' get digit from temp, convert to ASCII
    GOSUB LCDwrite                     ' write digit 
  NEXT 
  RETURN

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Jon Williams
    Applications Engineer, Parallax
    Dallas Office
  • studentstudent Posts: 12
    edited 2004-11-29 20:20
    I tried incorporating the subroutine that you suggested, but still no display on the LCD. I did try to insert a CrsHm, but received a syntax error. I must be close though??





    ' {$STAMP BS2}
    ' {$PBASIC 2.5}
    '
    ' ==============================================================================

    '
    ' Program Description
    '
    ' This program measures temperature using the Dallas Semiconductor DS1620
    ' temperature sensor and displays the results in fahrenheit.

    '
    ' I/O Definitions
    '
    DQ············· CON···· 0·················· ' DS1620.1 (data I/O)
    Clock·········· CON···· 1··················· ' DS1620.2
    Reset·········· CON···· 2···················· ' DS1620.3
    E·············· CON···· 8···················· ' LCD Enable pin· (1 = enabled)
    RS············· CON···· 3······················ ' Register Select (1 = char)
    '
    ' Constants
    '
    ClrLCD········· CON· $01···················· ' clear the LCD
    CrsrHm········· CON· $02····················· ' move cursor to home position
    DispLf········· CON· $18······················ ' shift displayed chars left
    DispRt········· CON· $1C······················· ' shift displayed chars right
    DDRam·········· CON·· $80····················· ' Display Data RAM control
    CGRam·········· CON· $40····················· ' Custom character RAM
    Line1·········· CON· $80···················· ' DDRAM address of line 1
    Line2·········· CON· $C0··················· ' DDRAM address of line 2
    RdTmp·········· CON···· $AA···················· ' read temperature
    WrHi··········· CON···· $01····················· ' write TH (high temp)
    WrLo··········· CON···· $02······················ ' write TL (low temp)
    RdHi··········· CON···· $A1······················· ' read TH
    RdLo··········· CON···· $A2······················ ' read TL
    StartC········· CON···· $EE····················· ' start conversion
    StopC·········· CON···· $22···················· ' stop conversion
    WrCfg·········· CON···· $0C··················· ' write config register
    RdCfg·········· CON···· $AC·················· ' read config register
    '
    ' Variables
    '
    tempIn········· VAR···· Word··················· ' raw temperature
    sign··········· VAR···· tempIn.BIT8············ ' 1 = negative temperature
    tSign·········· VAR···· Bit
    tempC·········· VAR···· Word··················· ' Celsius
    tempF·········· VAR···· Word··················· ' Fahrenheit
    LCDbus········· VAR···· OUTB··········· ' 4-bit LCD data
    char··········· VAR···· Byte············ ' character sent to LCD
    index·········· VAR···· Byte············· ' space for index
    '
    ' DATA statements
    Msg· DATA· "Present Temperature = "

    '
    ' Initialization
    '
    Initialize:
    ·DIRS = %1000000111111000··········· ' setup pins
    · GOSUB LCDinit···················· ' initialize LCD for 4-bit mode
    · HIGH Reset··································· ' alert the DS1620
    · SHIFTOUT DQ, Clock, LSBFIRST, [noparse][[/noparse]WrCfg, %10]···· ' use with CPU; free-run
    · LOW Reset
    · PAUSE 10
    · HIGH Reset
    · SHIFTOUT DQ, Clock, LSBFIRST, [noparse][[/noparse]StartC]······· ' start conversions
    · LOW Reset


    '
    ' Program Code
    '
    Main:
    · GOSUB Get_Temperature························ ' read the DS1620
    · DEBUG HOME
    · DEBUG "<<<DS1620>>>·· ", CR
    · DEBUG SDEC tempC, " C··· ", CR
    · DEBUG SDEC tempF, " F··· ", CR
    · GOSUB· LCDcommand
    · READ (Msg + index), char
    · GOSUB· ShowTemp_LCD
    ·· PAUSE 1000·································· ' pause between readings
    · GOTO Main

    '
    ' Subroutines
    '
    Get_Temperature:
    · HIGH Reset··································· ' alert the DS1620
    · SHIFTOUT DQ, Clock, LSBFIRST, [noparse][[/noparse]RdTmp]········· ' give command to read temp
    · SHIFTIN DQ, Clock, LSBPRE, [noparse][[/noparse]tempIn\9]·········· ' read it in
    · LOW Reset······································· ' release the DS1620
    · tSign = sign································· ' save sign bit
    · tempIn = tempIn / 2·························· ' round to whole degrees
    · IF (tSign = 0) THEN No_Neg1
    · tempIn = tempIn | $FF00························ ' extend sign bits for negative
    No_Neg1:
    · tempC = tempIn······························· ' save Celsius value
    · tempIn = tempIn */ $01CC······················ ' multiply by 1.8
    · IF (tSign = 0) THEN No_Neg2···················· ' if negative, extend sign bits
    · tempIn = tempIn | $FF00
    No_Neg2:
    · tempIn = tempIn + 32························· ' finish C -> F conversion
    · tempF = tempIn······························· ' save Fahrenheit value
    · RETURN
    ·· LCDinit:
    · PAUSE 500················· ' let the LCD settle
    · LCDbus = %0011·············· ' 8-bit mode
    · PULSOUT E,1
    · PAUSE 5
    · PULSOUT E,1
    · PULSOUT E,1
    · LCDbus = %0010·············· ' 4-bit mode
    · PULSOUT E,1
    · char = %00101000····················· ' multi-line mode
    · GOSUB LCDcommand
    · char = %00001100··········· ' disp on, crsr off, blink off
    · GOSUB LCDcommand
    · char = %00000110··········· ' inc crsr, no disp shift
    · GOSUB LCDcommand
    · RETURN
    · LCDcommand:
    ·· LOW RS················· ' enter command mode
    ·· RETURN
    LCDwrite:
    · LCDbus = char.HIGHNIB··········· ' output high nibble
    · PULSOUT E,1·············· ' strobe the Enable line
    · LCDbus = char.LOWNIB··········· ' output low nibble
    · PULSOUT E,1
    · HIGH RS················· ' return to character mode
    · RETURN

    · ShowTemp_LCD:
    · IF (tempIn.BIT15 = 1) THEN········· ' check sign bit
    ··· char = "-"························ ' - for negative temp
    · ELSE
    ··· char = " "························ ' blank for positive temp
    · ENDIF
    · GOSUB LCDwrite······················ ' write sign character
    · tempIn = ABS tempIn··············· ' convert tempt to absolute value
    · FOR index = 2 TO 0···················· ' loop through three digits
    ·· index = tempIn DIG index + "0"······ ' get digit from temp, convert to decimal
    ··· GOSUB LCDwrite···················· ' write digit
    · NEXT
    · RETURN
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2004-11-29 22:10
    If it'll help any, we recently built a Digital Thermostat which uses the DS1620, DS1302 and an LCD display and does display the temps on the LCD, as well as the time.· The display is serial interfaced though...

    I've attached the code.· Much of it is based on Jon William's work with the DS1620 and DS1302, as well as some mods from Tracy Allen.



    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Chris Savage

    Knight Designs
    324 West Main Street
    P.O. Box 97
    Montour Falls, NY 14865
    (607) 535-6777

    Business Page:·· http://www.knightdesigns.com
    Personal Page:··· http://www.lightlink.com/dream/chris
    Designs Page:··· http://www.lightlink.com/dream/designs
    bs2
    bs2
    Digital Thermostat.bs2
    18K
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