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Joined: 11/02/2018
Location: AustraliaPosts: 3321
| Posted: 06:13am 31 May 2026 |
Ok, so if you don't know which DS18x20 you have these two functions should work with any, including slow ones.
In the first one you can optionally set the Conversion Time in mS.
Usage:-
Print DS18x20ct(mm.info(pinno GPxx)) ' the default Conversion Time is 750mS
or
Print DS18x20ct(mm.info(pinno GPxx, mS_delay) '1000mS should cover most.
The second doesn't need it as it checks if the conversion is finished before reading. If not finished it returns to the main loop.
After reading it starts a new conversion, whish happens in the background as it returns to the main loop.
Usage:-
Print DS18x20(mm.info(pinno GPxx))
Function DS18x20ct(PinNbr As INTEGER, Delay As INTEGER) As FLOAT
' derived from DS18x20 test code by TassyJim
Local INTEGER T1,T2,T3,CpC,F
OneWire WRITE PinNbr,1,1,&h33 'read "family" ROM code
OneWire READ PinNbr,0,1,F ':Print F, "16=DS1820/DS18S20, 32=DS18S22, 40=DS18B20",
OneWire RESET PinNbr ' reset before command
OneWire WRITE PinNbr, 8, 2, &hCC, &h44 ' start conversion, adjust for slow units
If Delay < 10 then Delay = 750 ' maximum normal conversion time
Pause Delay
OneWire RESET PinNbr ' reset before command
OneWire WRITE PinNbr, 1, 2, &hCC, &hBE ' command read data
OneWire READ PinNbr, 0, 8, T1,T2,T3,T3,T3,T3,T3,CpC 'get the data
'process the data
If F=16 Then DS18x20ct = Str2bin(int16,Chr$(T1)+Chr$(T2))\2 -0.25 + (CpC-T3)/CpC
If F=40 or F=34 Then DS18x20ct = Str2bin(int16,Chr$(T1)+Chr$(T2))/16
End Function
' derived from DS18x20 test code by TassyJim
Local INTEGER T1,T2,T3,CpC,F
OneWire WRITE PinNbr,1,1,&h33 'read "family" ROM code
OneWire READ PinNbr,0,1,F ':Print F, "16=DS1820/DS18S20, 32=DS18S22, 40=DS18B20",
OneWire RESET PinNbr ' reset before command
OneWire WRITE PinNbr, 8, 2, &hCC, &h44 ' start conversion, adjust for slow units
If Delay < 10 then Delay = 750 ' maximum normal conversion time
Pause Delay
OneWire RESET PinNbr ' reset before command
OneWire WRITE PinNbr, 1, 2, &hCC, &hBE ' command read data
OneWire READ PinNbr, 0, 8, T1,T2,T3,T3,T3,T3,T3,CpC 'get the data
'process the data
If F=16 Then DS18x20ct = Str2bin(int16,Chr$(T1)+Chr$(T2))\2 -0.25 + (CpC-T3)/CpC
If F=40 or F=34 Then DS18x20ct = Str2bin(int16,Chr$(T1)+Chr$(T2))/16
End Function
PinNbr = MM.Info(pinno GP7)
Dim DStemp = DS18x20(PinNbr) 'purge old data and start new conversion
Dim integer n
Do 'Main Loop
t = timer
Print n;
DStemp = DS18x20(PinNbr) 'get Temp, if ready
If DStemp <> 1000 Then
Print
Print "Temp =";DStemp;"`C"
n = 0
EndIf
Do : Loop until Timer > 49.9
inc n,50
Loop
Function DS18x20(PinNbr As INTEGER) As FLOAT
' Adapted from DS18x20 test code by TassyJim
Local INTEGER done, T1, T2, T3, CpC, F
DS18x20 = 1000 ' standard error code
OneWire READ PinNbr, 4, 1, done ' is conversion finished?
If done = 0 Then Exit Function ' if not return to program
'Get the data
OneWire WRITE PinNbr,1,1,&h33 'read "family" ROM code
OneWire READ PinNbr,0,1,F ':Print F; " 16=DS1820/DS18S20, 32=DS18S22, 40=DS18B20",
OneWire RESET PinNbr ' reset before command
OneWire WRITE PinNbr, 1, 2, &hCC, &hBE ' command read data
OneWire READ PinNbr, 0, 8, T1,T2,T3,T3,T3,T3,T3,CpC ' get the data
' process the data
If F=16 Then Value = Str2bin(int16,Chr$(T1)+Chr$(T2))\2 -0.25 + (CpC-T3)/CpC
If F=40 or F=34 Then Value = Str2bin(int16,Chr$(T1)+Chr$(T2))/16
DS18x20 = Cint(Value * 10) / 10 'round to 1/10ths
'Start conversion, ready for next read
OneWire RESET PinNbr ' reset before command
OneWire WRITE PinNbr, 8, 2, &hCC, &h44 ' start conversion
End Function
End
Dim DStemp = DS18x20(PinNbr) 'purge old data and start new conversion
Dim integer n
Do 'Main Loop
t = timer
Print n;
DStemp = DS18x20(PinNbr) 'get Temp, if ready
If DStemp <> 1000 Then
Print "Temp =";DStemp;"`C"
n = 0
EndIf
Do : Loop until Timer > 49.9
inc n,50
Loop
Function DS18x20(PinNbr As INTEGER) As FLOAT
' Adapted from DS18x20 test code by TassyJim
Local INTEGER done, T1, T2, T3, CpC, F
DS18x20 = 1000 ' standard error code
OneWire READ PinNbr, 4, 1, done ' is conversion finished?
If done = 0 Then Exit Function ' if not return to program
'Get the data
OneWire WRITE PinNbr,1,1,&h33 'read "family" ROM code
OneWire READ PinNbr,0,1,F ':Print F; " 16=DS1820/DS18S20, 32=DS18S22, 40=DS18B20",
OneWire RESET PinNbr ' reset before command
OneWire WRITE PinNbr, 1, 2, &hCC, &hBE ' command read data
OneWire READ PinNbr, 0, 8, T1,T2,T3,T3,T3,T3,T3,CpC ' get the data
' process the data
If F=16 Then Value = Str2bin(int16,Chr$(T1)+Chr$(T2))\2 -0.25 + (CpC-T3)/CpC
If F=40 or F=34 Then Value = Str2bin(int16,Chr$(T1)+Chr$(T2))/16
DS18x20 = Cint(Value * 10) / 10 'round to 1/10ths
'Start conversion, ready for next read
OneWire RESET PinNbr ' reset before command
OneWire WRITE PinNbr, 8, 2, &hCC, &h44 ' start conversion
End Function
End