' Name        : TEMP_DS1822.pbp
' Compiler    : PICBASIC PRO Compiler 2.60
' Assembler   : PM or MPASM
' Target PIC  : 40-pin 16F877, 877A or similar
' Hardware    : LAB-X1 Experimenter Board
' Oscillator  : 4MHz external crystal
' Keywords    : DS1822, DS18B20, OWIN, OWOUT
' Description : PICBASIC PRO program to read DS1822 or DS18B20 1-wire
' temperature sensor using OWIN and OWOUT commands and display
' temperature on LCD.
'
temperature     VAR     WORD            ' Temperature storage
count_remain    VAR     BYTE            ' Count remaining
count_per_c     VAR     BYTE            ' Count per degree C

DQ      VAR     PORTC.0                 ' One-wire data pin

' Define LCD registers and bits
DEFINE  LCD_DREG        PORTD
DEFINE  LCD_DBIT        4
DEFINE  LCD_RSREG       PORTE
DEFINE  LCD_RSBIT       0
DEFINE  LCD_EREG        PORTE
DEFINE  LCD_EBIT        1


        ADCON1 = %00000111              ' Set PORTA and PORTE to digital
        Low PORTE.2                     ' LCD R/W line low (W)


mainloop:
        OWOUT DQ, 1, [$CC, $44] ' Start temperature conversion

        pause 2000

        OWOUT DQ, 1, [$CC, $BE]         ' Read the temperature
        OWIN DQ, 0, [temperature.LOWBYTE, temperature.HIGHBYTE]

        ' Calculate temperature in degrees C to 2 decimal places
        ' (not valid for negative temperature)
        temperature = temperature */ 1600
        LCDOUT $fe, 1, DEC (temperature / 100), ".", DEC2 temperature, " C"

        ' Calculate temperature in degrees F to 2 decimal places 
        ' (not valid for negative temperature)
        temperature = (temperature */ 461) + 3200
        LCDOUT $fe, $c0, DEC (temperature / 100), ".", DEC2 temperature, " F"

GoTo mainloop                   ' Do it forever