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More than one ds18b20

Runtime 🇬🇧
alverman
2018-05-10
2018-05-12

  • alverman - 2018-05-10

    Good evening,
    I'm trying to change the program that measures the temperature with ds18b20.
    The sample program manages one but I would like to add one more.
    I added a rTemp1 variable and assigned it to DS18B20_1.rTemp ----- rTemp1
    But I can not understand why the temperature display is the same as the first DS18B20.

    What should I do to add other sensors?

    Thanks, Alberto

     

  • alverman - 2018-05-11

    Goodmorning everyone
    I'm trying to understand why I can not see the two temperatures.
    The temperature of only one DS18b20 is always shown.
    If I touch the DS18B20_1 nothing changes if I touch the DS18B20 change both

    What's wrong ?

    This is var

    PROGRAM OneWire
VAR
   tempExt: REAL;
   tempCaldaia: REAL;
   
   rTemp: REAL;
   astrID: ARRAY[1..20] OF STRING;
   ui: uINT;
   x: BOOL;
   actDate :SYSTIMEDATE;
   dwActDate:DWORD;
   dtTimestamp:DT;
END_VAR

    This is code

    IF NOT x THEN
   x := TRUE;
   //scan function
   Onewire_master.Scan();
   FOR ui:=1 TO MIN(Onewire_master.uiScannedDevices, 20) DO
      astrID[ui] := Onewire_master.pasScannedDevices^[ui-1].StringRepresentation;
      //dynamic write the scanned sensors to the configuration
      DS18B20.ID := Onewire_master.pasScannedDevices^[ui-1];
   END_FOR
END_IF
actDate := DS18B20.stdTimeStamp;
SysTimeRtcConvertDateToUtc(actDate,dwActDate);
dtTimestamp := DWORD_TO_DT(dwActDate);
tempExt:=DS18B20.rTemp;
tempCaldaia:=DS18B20_1.rTemp;

    IMG: t1.png

     

  • alverman - 2018-05-12

    Solved

    PROGRAM OneWire
VAR
   tempExt: REAL;
   tempCaldaia: REAL;
   
   rTemp: REAL;
   astrID: ARRAY[1..20] OF STRING;
   ui: uINT;
   x: BOOL;
   actDate :SYSTIMEDATE;
   dwActDate:DWORD;
   dtTimestamp:DT;
END_VAR

    IF NOT x THEN
   x := TRUE;
   //scan function
   Onewire_master.Scan();
   FOR ui:=1 TO MIN(Onewire_master.uiScannedDevices, 20) DO
      astrID[ui] := Onewire_master.pasScannedDevices^[ui-1].StringRepresentation;
      //dynamic write the scanned sensors to the configuration
//      DS18B20.ID := Onewire_master.pasScannedDevices^[ui-1];
   END_FOR
END_IF
T_Esterna.ID := Onewire_master.pasScannedDevices^[0];
T_Caldaia.ID := Onewire_master.pasScannedDevices^[1];
actDate := T_Esterna.stdTimeStamp;
SysTimeRtcConvertDateToUtc(actDate,dwActDate);
dtTimestamp := DWORD_TO_DT(dwActDate);
     

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