Read DS18S20

[PICante]

Hi skimask!

Sorry, I’m somewhat confused here I don’t know what to believe in (of curse I believe in you!) since I also got a compilation error saying: “ERROR: Macro OWINSTR?W not found in macro file.”

Huuh?


Edit: Hey… it’s the other way around, it says 12-bits not supported! (found my glasses) :-) . Then (as usual) I must be doing something else wrong!

[skimask]

since I also got a compilation error saying: “ERROR: Macro OWINSTR?W not found in macro file.”

The latest PBP update should fix that problem.
If not, there's a thread somewhere around here relating a problem similar to that..somewhere...

Edit: Hey… it’s the other way around, it says 14-bits not supported! (found my glasses) :-) . Then (as usual) I must be doing something else wrong!

I don't know which manual you're reading.
My manual says 12-bits aren't supported using the REP and STR modifiers. I'd tend to believe that due to the stack/ram constraints of 12 bit devices.

[PICante]

Yes, my manual also says 12-bit. edited almost instantaneously! :-)

I have got the P250a patch installed, can’t seem to find any newer?

[skimask]

Yes, my manual also says 12-bit. edited almost instantaneously! :-)

I have got the P250a patch installed, can’t seem to find any newer?

There's a b patch out now.

Show the code...

[PICante]

I will try to find and run the patch to find out if that’s the culprit.

Thanks ski

[PICante]

Patch in place..... No, that did not cancel the compile error!
Here’s the code:

READTEMP:

OWOUT PORTA.5,1,[$CC, $44]                       ' SEND Start Temperature Conversion command

 
    OWOUT PORTA.5,1,[$CC, $BE]                   ' SEND Read Temperature command

 
    OWIN PORTA.5,0,[STR dq\9]                    ' Retrieve all 9 bytes of data

    RawTemp.Byte0 = dq[0]

    RawTemp.byte1 = dq[1]

    IF RawTemp.8 = 1 then                       ' Check IF temperature is a negative reading

 

        SignC = Negative

        RawTemp.lowbyte = RawTemp.lowbyte ^ 255               ' Invert data

        ELSE

        SignC = Positive

                 ENDIF

 

    dummy = RawTemp.0                                 ' Store the half degree indicator bit

 

    TempC = ((RawTemp.lowbyte) >> 1) * 100          ' Divide raw data by 2 to give real temperature

 

    TempC = TempC + (dummy * 50)                    ' Add the half degree is present

 

    IF SignC = Negative then                       ' Only proceed IF temperature is negative

 

        IF TempC => 1770 then   

            SignF = Negative

            TempF = (TempC + 5000) * 900

            TempF = div32 500

            TempF = TempF - 12200

            RETURN

 

            ELSE

            SignF = Positive

            TempF = (TempC + 5000) * 900

            TempF = div32 500

            TempF = 12200 - TempF

            RETURN

 

        ENDIF    

    ENDIF

    SignF = Positive

    TempF = TempC * 18 / 10 + 3200

    RETURN

Thanks!

[Acetronics2]

Hi,

Is not that much simpler than yout modifyer and the two following lines :

OWIN PORTA.5,0,[STR dq\9]                    ' Retrieve all 9 bytes of data

    RawTemp.Byte0 = dq[0]

    RawTemp.byte1 = dq[1]

( taken from a Malc C example )

   OWIN    Porta.5, 2, [R_Temp.Lowbyte, R_Temp.Highbyte]      ' Read two bytes / end comms

Alain

[skimask]

I know that's not ALL of the code...