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EnableExplicit
;Measuring T is important, so always use EnableExplicit!!!
;                          ===============================                   

;This listing Read one or more DS18B20 without using PIGPIO or other libs.
;=========================================================================
;I saw a lot of listings on the internet, but lot of them did not work good or gave errors.
;Those using libs were sometimes to complicated.
;So I was very frustrated to obtain no good working T-measurement.
;So I decide to make my own listing.
;Purebasic surprised my with an (till to day!!!) errorless working T-measuring.
;So I will deal with You my listing.

;If You can make something better or efficienter, please deal it on this forum.

;Tested on RasperryPI3 Model B+ met Linux en xfce desktop: 
;Testtime: 3 ours, continue reading 3 DB18B20 sensors... Works without errors!
;I let run this listing during 5 1/2 hours with 8000 loops, each with 3 DB18B20 sensors.
;I'm very glad to announce I became:
;24000 times a reading of the DSB18B20 file without no one error!
;================================================================

;Do not forget there is always a sensor-toleration for temperature-result AND for responstime.
;So, if You use 1 DB18B20 (only 1 responstime!!!) You need to incorporate one or more delay()
;statements in Your listing to obtain no errors. In that case, You need to test it out Yourself.

;In case of program errors during runtime,
;then test again With Delay(xxx) milliseconds, see listing
;Tip: start With 25 milliseconds and increase of necessery.
;AND... test again during minimal several ours!!! (I take 3 ours as absolute minimum test time).
;Do such test again when You replace a sensor.

;=====================================Disclaimer =========================================
;                    Do all your test very carefully And punctual.
;=========================================================================================
;    With a failing temperature-control, You easely obtain very dangerous situations!
;=========================================================================================
;For all Your home made constructions: Read and follow all rules and laws of Your country.
;=========================================================================================
;P.e.: All metal parts of my home made beerboiling installations have perfect earth connections.


Define.s PathName , FullPathName,  Path_to_w1slave, sensormap
Define.s Temperature_string, content
Define.l File, start, sensornr, test, x
Define.l totalSeconds , hr, min, sec, MaxNumberSensors
Define.d Temperature
Define.q Tstart,Telapsed,Tmeetpunt 

;Full pathname of my sensor3 is:
;Path_to_w1slave = "/sys/devices/w1_bus_master1/28-3c01d60706a2/w1_slave"
;                                               xxxxxxxxxxxxxxx 
;xxxxxxxxxxxxxxx = the sensormap
; Replace white those of Your specifieke sensor(s) in the select case below.

;Tip: In Linux You can also search in terminal with "locate w1_slave" to find the path

MaxNumberSensors = 3 
;For my beerbrewing I only use 3 sensors
;1 in my beervessel, 1 in my watercooker, 1 in my plate cooler (to not spoil water...).

;Line below for testing purposes
Tstart = ElapsedMilliseconds()

;For next loop for testpurpose.
For test = 1 To 50
  
  For sensornr = 1 To MaxNumberSensors 
    
   Select sensornr 
     Case 1 
       sensormap = "28-0316a279f80d"  
     Case 2 
       sensormap = "28-0319a27920d7"
     Case 3 
       sensormap = "28-3c01d60706a2"
     Case 4 
       sensormap = "28-3c01d607bcca"
     Case 5 
       sensormap = "28-3c01d607e340"
     Default 
       sensormap = "28-0316a279f80d" ;I take sensor 1 as Default sensor (my beervessel...)
   EndSelect   
 
     FullPathName = "/sys/devices/w1_bus_master1/" + sensormap +"/w1_slave" 
  
  
     File = ReadFile(#PB_Any, FullPathName)
    ;Delay (50) 

    If File
      Repeat       
        
        Temperature = #False
        content = ReadString(File) 
        ;Delay (50)
        ;Debug content , for testpurpose
        start = FindString(Content, "t=", 1)
    
        If start > 0     
          Temperature_string = Mid(Content, start + 2, 7)     ;+2 because we do'nt need t=    
          Temperature = ValF(Temperature_string) / 1000       ; Convert to centigrade Celsius
          Temperature = Round (Temperature,#PB_Round_Nearest) ;1°C is OK for my beerbrewing installation  
          If Temperature <> #False
            Debug Temperature
            ; First possibility to store here the temp-data:
            ; P.e.: Store temperatures in a global array to use elders in Your programma.
            ; See further: "Second possibility"
          Else  
            Debug "Could not measure Temperature"
            Break    
          EndIf  
       
          Break     
          
        EndIf      
        
      Until Eof(File)       
      CloseFile(File) 
      
    Else
      
      Debug "Could not read sensor number :" +Str (sensornr)
      Debug "Could not open sensorfile: "
      Debug  FullPathName
      Break     
      ; P.E.: For safety call here a procedure,
      ; play an alarmsound, swith off all heaterelements, close all taps etc,etc...
    EndIf
    
  Next sensornr
  ;Second Possibility to call from here procedures.
  ;P.E. Switch heaterelements on or off.
  ;The outer For next loop could be p.e. a Repeat-Forever or Repeat-while and other.

Next test ;For next loop for testpurpose, see other comments.
 
;Measuring time, for tespurpose:
;Telapsed = ElapsedMilliseconds() - Tstart
;totalSeconds=Telapsed/1000
;hr = totalSeconds/3600
;min = (totalSeconds - 3600*hr) / 60
;sec = totalSeconds - 3600*hr - 60*min
;Debug Str(hr) + " uur " + Str(min) + " min " + Str(sec) + " sec"

;Other possibility to obtain data on Your screen:
;P.E.: MessageRequester("Temperature", Temp, #PB_MessageRequester_Ok)

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Temperature = ValD(Temperature_string) / 1000.0