This module is part of the original MMBasic library. It is reproduced here with kind permission of Hugh Buckle and Geoff Graham. Be aware it may reference functionality which has changed or is deprecated in the latest versions of MMBasic.¶
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FUN1WIRE.BAS
Print "The temperature is: " Format$(GetTemp(18), "%2.1f")
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' Function to get the temperature from a Dallas DS18B20.
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Fun GetTemp(PinNbr)
Local T1, T2, b, t
OWReset PinNbr ' reset
OWWrite PinNbr, 1, 2, &hcc, &h44 ' start conversion
Pause 100
t = Timer
Do
If Timer - t > 1000 Then Error "Sensor not responding"
OWRead PinNbr, 4 , 1 , b ' conversion done?
Loop Until b = 1
OWWrite PinNbr, 1, 2, &hcc, &hbe ' command read data
OWRead PinNbr, 2, 2, T1, T2 ' get the data
GetTemp = ((T2 And &b111) * 256 + T1) / 16
If T2 And &b1000 Then GetTemp = -GetTemp ' adjust if < 0
End Fun