'****************************************************************
'*  Name    : DS18B20 Temperature sensor reading                                    *
'*  Author  : Daniel Bowen  [email protected]                                    *
'*  Notice  : Copyright (c) 2007 UTARC www.utarc.org                         *
'*          : All Rights Reserved                               *
'*  Date    : 2/20/2007                                         *
'*  Version : 1.0                                               *
'*  Notes   : Displays temperature from DS18B20 in Celsius on hardware serial port
'*			: Microcontroller used: PicMicro 18F4620
'*          :                                                   *
'****************************************************************

INCLUDE "MODEDEFS.BAS"
DEFINE OSC 20
DEFINE LOADER_USED 1
DEFINE HSER_BAUD 2400
DEFINE ADC_CLOCK 1
DEFINE ADC_BITS 10
DEFINE ADC_SAMPLEUS 50
SYMBOL LF=$0A
CMCON=$07
ADCON1=%00001100
TRISA=%00110111
TRISB=%01111101
TRISC=%10010100
TRISD=%10010100
TRISE=%00000000

'*** Pin assignments
TempIn VAR PORTA.4

'*** Temp Read Variables ***
char                    VAR     BYTE
TTData VAR BYTE
TSign VAR BIT
TempData VAR WORD
Sign VAR TEMPDATA.15





START:

    GOSUB TEMPINREAD
    LOOKUP TSIGN, ["+","-"], CHAR
    HSEROUT [char,DEC3 TEMPDATA, "C" CR,LF] ' and display it  0=positive, 1=negative

GOTO START


TEMPINREAD:
    OWOUT TEMPIN,1,[$CC,$44]
    HIGH TEMPIN
    PAUSE 10
    OWOUT TEMPIN,1,[$CC,$BE]
    OWIN TEMPIN,0,[TEMPDATA.LowByte,TEMPDATA.HighByte,SKIP 7]
    tSign = SIGN ' save sign bin
    IF TSIGN=1 THEN
        TEMPDATA = $FFFF-TEMPDATA
        TEMPDATA = TEMPDATA + 1
    ENDIF
    TEMPDATA = TEMPDATA/16
    RETURN

http://www.utarc.org/wiki/index.php?title=Source_Code

Displays temperature from DS18B20 in Celsius on hardware serial port

PicBasic Interfacing 18F PIC with Temperature Sensor Maxim DS18B20

PicBasic