This library is based on the following open source project: http://www.pjrc.com/teensy/td_libs_OneWire.html
License: https://github.com/PaulStoffregen/OneWire/blob/master/OneWire.cpp
It implements Dallas 1-wire protocol.
Example of reading the temperature:
Depends on rOneWire and rRandomAccessFile libraries.
Note that unlike the original C example, the main thread is not blocked here while waiting for the data to be ready.
License: https://github.com/PaulStoffregen/OneWire/blob/master/OneWire.cpp
It implements Dallas 1-wire protocol.
Example of reading the temperature:
Depends on rOneWire and rRandomAccessFile libraries.
B4X:
Sub Process_Globals
Public Serial1 As Serial
Private onewire As OneWire
Private timer1 As Timer
Private bc As ByteConverter
Private address(8) As Byte
Private type_s As Boolean
End Sub
Private Sub AppStart
Serial1.Initialize(115200)
Log("AppStart")
onewire.Initialize(10)
timer1.Initialize("timer1_Tick", 2000)
timer1.Enabled = True
End Sub
Sub Timer1_Tick
If onewire.Search(address) = False Then
onewire.ResetSearch
Log("No more addresses.")
Return
End If
Log("ROM = ", bc.HexFromBytes(address))
If onewire.CRC8(address, 7) <> address(7) Then
Log("CRC is not valid!")
Return
End If
Select address(0)
Case 0x10
Log("Chip = DS18S20")
type_s = True
Case 0x28
Log("Chip = DS18B20")
type_s = False
Case 0x22
Log("Chip = DS1822")
type_s = False
Case Else
Log("Device is not a DS18x20 family device.")
Return
End Select
onewire.Reset
onewire.Select(address)
onewire.Write(0x44, True)
'give it 1 second to read the temperature
CallSubPlus("ReadTemparature", 1000, 0)
End Sub
Private Sub ReadTemparature (u As Byte)
onewire.Reset
onewire.Select(address)
onewire.Write(0xBE, False)
Dim data(12) As Byte
onewire.ReadBytes(data, 9)
Log("Data = ", bc.HexFromBytes(data))
Log("CRC = ", bc.HexFromBytes(Array As Byte(onewire.CRC8(data, 8))))
Dim raw As Int = Bit.Or(Bit.ShiftLeft(data(1), 8), data(0))
If type_s Then
raw = Bit.ShiftLeft(raw, 3)
If data(7) = 0x10 Then
raw = Bit.And(raw, 0xFFF0) + 12 - data(6)
End If
Else
Dim cfg As Byte = Bit.And(data(4), 0x60)
If cfg = 0 Then
raw = Bit.And(raw, Bit.Not(7))
Else if cfg = 0x20 Then
raw = Bit.And(raw, Bit.Not(3))
Else if cfg = 0x40 Then
Bit.And(raw, Bit.Not(1))
End If
End If
Dim celsius As Double = raw / 16
Dim fahrenheit As Double = celsius * 1.8 + 32
Log("Temperature = ", NumberFormat(celsius, 0, 2), " Celsius, " _
, NumberFormat(fahrenheit, 0, 2), " Fahrenheit")
End SubNote that unlike the original C example, the main thread is not blocked here while waiting for the data to be ready.
