Reading DS18S20 and DS18B20 In Same Program


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  1. #1
    Join Date
    Dec 2012
    Location
    Georgia, USA
    Posts
    18

    Default Reading DS18S20 and DS18B20 In Same Program

    I'm new to PBP and have been working with some DS18S20 and DS18B20 Sensors.
    I'm using a PIC 16F877 here is my loop that reads the DS18S20. Is there a way
    to detirmine if the sensor is a DS18B20 the on the Pin instead of a DS18S20?
    Evidently the 18B20 requires a different routine to read an determine the temperature.
    I get +22.06C on all 3 of the DS18S20 senors, but +152.87C and 152.81 on my DS18B20
    sensors.



    Thanks In Advance
    Larry






    DEFINE OSC 10 ' We're using a 10MHz oscillator
    BAUD CON 84 ' N9600 for serial
    CR CON 13 ' CR serial
    LF CON 10 ' N9600 for serial LCD
    SO VAR PORTC.6 ' Pin to for serial Out
    SI VAR PORTC.7 ' Pin to for serial In

    ' Allocate variables
    command var byte ' Storage for command
    i var byte ' Storage for loop counter
    sn var byte 'Polling Sensor Number
    Rsn var byte 'Real Sensor Number
    TempR var word ' Storage for temperature
    TempS var word [12] 'Array To Store and send all Temps at one time
    'DS1 var PORTB.0 ' Alias DS1820 data pin
    'DS2 var PORTB.1 ' Alias DS1820 data pin
    'DS3 var PORTB.2 ' Alias DS1820 data pin
    'PORTB.3 is Reserved
    'DS4 var PORTB.4 ' Alias DS1820 data pin
    'DS5 var PORTB.5 ' Alias DS1820 data pin
    'DS6 var PORTB.6 ' Alias DS1820 data pin
    'DS7 var PORTB.7 ' Alias DS1820 data pin


    'DS8 var PORTC.0
    'DS9 var PORTC.1 ' Alias DS1820 data pin
    'DS10 var PORTC.2 ' Alias DS1820 data pin
    'DS11 var PORTC.3 ' Alias DS1820 data pin
    'DS12 var PORTC.4 ' Alias DS1820 data pin

    'PORTB.0 = 0-7
    'PORTC.0 = 8-15

    '*****DS1820 VARS AND SETTINGS*******
    count_remain var byte 'DS1820 counter of remain bits
    count_per_c var byte 'DS1820 counter per C bits
    TempNeg var byte 'temperature sign -/+
    TpNeg var byte [12] 'temperature sign -/+
    '**********************************
    SEROUT2 SO,BAUD, ["PIC Controller Ready",CR,LF]

    sn = 0
    Rsn =1
    Main:

    SEROUT2 SO,BAUD, ["Reading Sensor ",DEC Rsn,CR,LF]
    i = 0
    if sn = 3 then sn = 4
    gosub Read_Temp

    if i=10 then ErrX
    if TempR=$FFFF then Error

    TempS[Rsn-1] = TempR
    TpNeg[Rsn-1] = TempNeg
    'gosub Disp_Temp
    sn = sn + 1
    Rsn = Rsn + 1
    if sn = 13 then
    gosub Disp_AllTemp
    sn = 0
    Rsn =1
    endif
    TempR=$FFFF

    pause 200
    SEROUT2 SO,BAUD, ["========================================",CR, LF]
    SEROUT2 SO,BAUD, [CR,LF]
    goto Main

    Read_Temp:

    OWOut sn, 1, [$CC, $44] ' Start temperature conversion
    waitloop1:
    OWIn sn, 4, [count_remain] ' Check for still busy converting
    If count_remain = 0 Then
    pause 100
    i = i + 1
    if(i = 10)then return
    goto waitloop1
    endif
    OWOut sn, 1, [$CC, $BE] ' Read the temperature
    OWIn sn, 0, [TempR.LowByte, TempR.HighByte, Skip 4, count_remain, count_per_c]


    if TempR = $FFFF then return
    if (TempR.HighByte = $FF) and (TempR.LowByte <> 0) then
    TempNeg = "-"
    TempR = TempR ^ $FFFF
    TempR = ((TempR >> 1)*100) - 25 + ((count_per_c + count_remain) * 100) / count_per_c
    else
    if (TempR.HighByte < $FF) and (TempR.LowByte <> 0) then
    TempNeg = "+"
    TempR = ((TempR >> 1)*100) - 25 + ((count_per_c - count_remain) * 100) / count_per_c
    else
    '************************************************
    TempR=$0000 ' THIS IS ONLY NEED TO DEFINE !!!
    '************************************************
    endif
    endif
    return

    Disp_AllTemp:
    SEROUT2 SO,BAUD,[2,","]
    for i = 0 to 11
    if TpNeg[i] = "E" then
    SEROUT2 SO,BAUD, ["TS",dec i+1,",E/R|"]
    elseif TpNeg[i] = "N" then
    SEROUT2 SO,BAUD, ["TS",dec i+1,",N/R|"]
    else
    SEROUT2 SO,BAUD, ["TS",dec i+1,",",TpNeg[i], DEC (TempS[i] / 100),".", DEC2 TempS[i], "C|"]
    endif
    TempS[i] = 0
    TpNeg[i] = 0
    next



    SEROUT2 SO,BAUD,[CR,LF]

    'SEROUT2 SO,BAUD, ["Raw", IBIN16 TempR,CR,LF]
    'SEROUT2 SO,BAUD, ["---------------------------------" ,CR,LF]


    return

    Error:
    SEROUT2 SO,BAUD, ["ERROR - Reading Sensor:", dec Rsn ,CR,LF]
    TempS[Rsn-1] = 0
    TpNeg[Rsn-1] = "E"
    sn = sn + 1
    Rsn = Rsn + 1
    if sn = 13 then
    sn = 0
    Rsn =1
    endif

    goto Main

    ErrX:
    ' "!!!ERROR!!!", $fe, $C0, "Reading Temp."
    SEROUT2 SO,BAUD, ["Sensor: ",dec Rsn," Not Reporting" ,CR,LF]
    TempS[Rsn-1] = 0
    TpNeg[Rsn-1] = "N"
    sn = sn + 1
    Rsn = Rsn + 1
    if sn = 13 then
    sn = 0
    Rsn =1
    endif
    goto Main


    end

  2. #2
    Join Date
    Jul 2003
    Location
    Colorado Springs
    Posts
    4,959

    Default Re: Reading DS18S20 and DS18B20 In Same Program

    You can determine which device it is by reading the "Family" code.

    Issue a READROM command ($33).
    Then read back 1 byte.

    $10 = DS18S20 or DS1820
    $28 = DS18B20
    DT

  3. #3
    Join Date
    Dec 2012
    Location
    Georgia, USA
    Posts
    18

    Default Re: Reading DS18S20 and DS18B20 In Same Program

    Thank you Darrel

    Works great !

    I was studying your code in this post
    http://www.picbasic.co.uk/forum/show...ight=OWPIN%3FW


    Will the code parameters be the same as before mod:

    OWpins VAR WORD[16] ; assign pins for OneWire commands.
    OWpins(0) = $0000 ; PORTA is 0, bit 0 ; Assignments can be in any order
    OWpins(1) = $0002 ; bit 2 ; Shown sequentially here for clarity
    OWpins(2) = $0100 ; PORTB is 1, bit 0
    OWpins(3) = $0101 ; bit 1
    OWpins(4) = $0102 ; bit 2
    OWpins(5) = $0103 ; bit 3
    OWpins(6) = $0104 ; bit 4
    OWpins(7) = $0105 ; bit 5
    OWpins(8) = $0106 ; bit 6
    OWpins(9) = $0107 ; bit 7
    ...
    OWpins(15) = $0307 ; PORTD is 3, bit 7

    Will the code parameters be the same as before the mod:?

    Before Mod:
    OWOut sn, 1, [$CC, $BE] ' Read the temperature
    After Mod:
    OWOut OWpins(sn), 1, [$CC, $BE] ' Read the temperature

    Thank you!
    and thanks for sharing your knowledge.


    I have pretty much went through reading Henrik's, Bruce's, your answers to questions for
    the past two weeks and it has really helped me get an understand how powerful this PBP
    compiler is.

    Thanks again !
    Larryd

  4. #4
    Join Date
    Jul 2003
    Location
    Colorado Springs
    Posts
    4,959

    Default Re: Reading DS18S20 and DS18B20 In Same Program

    You're welcome Larryd.

    Yes, the rest of the prarameters are still the same.
    Only the pin assignment method changes.

    I had forgotten about that thread.
    But after looking at it again, and since you're using DS1820's ... You might want to set the pins in EEPROM.
    Then the pin assignments can be changed later at Run-Time via a menu or serial commands.

    Maybe somthing like ...
    Code:
    OWpins VAR WORD[10] ; default pins for OneWire commands.
    Sensor0  DATA WORD $0000  ; PORTA.0
    Sensor1  DATA WORD $0001  ;       1
    Sensor2  DATA WORD $0100  ; PORTB.0
    Sensor3  DATA WORD $0101  ;       1
    Sensor4  DATA WORD $0103  ;       3
    Sensor5  DATA WORD $0200  ; PORTC.0
    Sensor6  DATA WORD $0201  ;       1
    Inside   DATA WORD $0204  ;       4
    Outside  DATA WORD $0205  ;       5
    Bedroom  DATA WORD $0206  ;       6
    
    
    Idx  VAR BYTE
    Addr VAR WORD
    
    Addr = Sensor0
    FOR Idx = 0 TO 9          ; Initialize OW pins from EEPROM
      READ Addr + Idx<<1, WORD OWpins(Idx)
    NEXT Idx
    You'll need PBP 2.60 or later.
    Last edited by Darrel Taylor; - 26th January 2013 at 20:42. Reason: Changed Addr for READ ... again
    DT

  5. #5
    Join Date
    Dec 2012
    Location
    Georgia, USA
    Posts
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    Default Re: Reading DS18S20 and DS18B20 In Same Program

    Thanks Darrel

    I like having the ability to name the sensors, I will give this a try.
    Thanks Again.

    Ld

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