DS18S20 -> 850 Grad Celsius ???
Hallo,
habe einen DS18S20 an Portb.0 meines mega32 hängen. Folgendes Programm gibt mir als Temperatur immer 850 aus:
Code:
'--- Controller ---
$regfile = "m32def.dat"
$crystal = 16000000
$baud = 4800
$hwstack = 32
$swstack = 10
$framesize = 40
'--- Grafikroutine ---
$lib "glcdKS108.lib"
'--- DS18S20 ---
Config 1wire = Portb.0
'--- Declare Subs ---
Declare Sub Init
Declare Sub Convallt
Declare Function Decigrades(byval Sc(9) As Byte) As Integer
'--- Dims ---
Dim B As Byte
Dim W As Word
Dim Dg As Integer
Dim Min1 As Integer
Dim Min2 As Integer
Dim Max1 As Integer
Dim Max2 As Integer
Dim Dsid1(8) As Byte
Dim Sc(9) As Byte
'--- Grafikdisplay ---
Config Graphlcd = 128 * 64sed , Dataport = Porta , Controlport = Portc , Ce = 1 , Ce2 = 0 , Cd = 2 , Rd = 3 , Reset = 4 , Enable = 5
Cls
Showpic 0 , 0 , Lcdblank
Setfont Font6x8
Lcdat 2 , 32 , "Sensorcheck"
Line(0 , 20) -(128 , 20 ) , 1
Wait 1
'--- Sensor ---
Setfont Kayfont5x5
Dsid1(1) = 1wsearchfirst()
If Dsid1(8) = Crc8(dsid1(1) , 7) Then
Lcdat 4 , 2 , "CRC OK Sensor"
Wait 1
For B = 1 To 8
Lcdat 5 , 2 , Hex(dsid1(b))
Next
End If
'--- Main Hauptprogramm ---
Main:
Call Convallt ' "Convert ALL T on the 1w-bus"
Waitus 200 : Waitus 200 : Waitus 200 : Waitus 200 'if you use 2-wire, could be reduced to 200us
1wverify Dsid1(1) 'Issues the "Match ROM "
Locate 1 , 1
If Err = 1 Then
Lcdat 6 , 2 , "Err " 'Err = 1 if something is wrong
Elseif Err = 0 Then 'lcd " Sensor found"
1wwrite &HBE
Sc(1) = 1wread(9) 'read bytes into array
If Sc(9) = Crc8(sc(1) , 8) Then
Dg = Decigrades(sc(9))
Lcdat 7 , 2 , Dg
End If
End If
Wait 1
Goto Main
'--- Temperatur konvertieren ---
Sub Convallt
1wreset ' reset the bus
1wwrite &HCC ' skip rom
1wwrite &H44 ' Convert T
End Sub
'--- Funktion zum auslesen des Temperatursensors ---
Function Decigrades(byval Sc(9) As Byte)
Dim Tmp As Byte , T As Integer , T1 As Integer
Tmp = Sc(1) And 1 ' 0.1C precision
If Tmp = 1 Then Decr Sc(1)
T = Makeint(sc(1) , Sc(2))
'Print Hex(t)
'Print T
T = T * 50 'here we calculate the 1/10 precision like
T = T - 25 'DS18S20 data sheet
T1 = Sc(8) - Sc(7)
T1 = T1 * 100
T1 = T1 / Sc(8)
T = T + T1
Decigrades = T / 10
'As integer, this routine gives T*10, with 1/10 degree precision
End Function
'--- Includes ---
$include "kayfont5x5.font"
$include "font6x8.font"
'--- Bilder ---
Lcdblank:
$bgf "lcdblank.bgf"
Die ID bekomme ich angezeigt. Hab 2 DS18S20 ausprobiert. Am Datenausgang habe ich einen 4,7k Pullup. Vielleicht sitz ich ja auch nur auf der Leitung. Vielleicht kann mir ja jemand von Euch helfen.
mfg Kay
