دماسنج با lm335

[mehrdadgh]

سلام
برنامه زیر مربوط به دماسنج کتاب اقای کاهه هستش ولی من مدار رو بستم دما رو 222 درکه نشون میداد!!
به نظرتون اشکالش از کجاست؟

$regfile = "m32def.dat"
'We use internal osc 4000000 for atmega32
$crystal = 4000000
Config Lcdpin = Pin , Db4 = Portc.1 , Db5 = Portc.2 , Db6 = Portc.3 , Db7 = _
Portc.4 , E = Portd.2 , Rs = Portd.3
Config Lcd = 16 * 2
Config Adc = Single , Prescaler = Auto
Start Adc
Config Timer0 = Timer , Prescale = 1024
Enable Interrupts
Enable Timer0
On Timer0 Temp_sample
Start Timer0
Dim Sample As Word
Dim Temp As Word
Dim Temp_final As Integer
Dim Sum As Integer
Deflcdchar 0 , 24 , 24 , 32 , 32 , 32 , 32 , 32 , 32    '' sign -> (')
Cursor Off
Cls
Do


Loop
end              'end program

Temp_sample:
Incr Sample                         'incr sampling counter
Temp = Getadc(0)                      'read adc(0) every 65ms
Sum = Sum + Temp                      'sum the sample data
If Sample = 15 Then                     '20 samples
  Sample = 0                        'reset sample counter
  Stop Timer0                       'stop timer to calculation
  Sum = Sum / 15                      'mean calculation
  Sum = Sum - 558                     'decrementing offset
  Temp_final = Sum / 2                   'every 10mv is almost 2 step of adc (adc step=5/1023=4.88mv)
  Select Case Temp_final
   Case Is =< 10 :                    'compare temperature
     Home L
     Lcd " Low  "
   Case 11 To 34 : 'compare temperature
     Home L
     Lcd " Normal "
   Case Is >= 35 :                    'compare temperature
     Home L
     Lcd " High  "
  End Select

  Home
  Lcd Temp_final ; Chr(0) ; "C  "            'show temperature
  Start Timer0
  Sum = 0
End If
Return

[vahid2010]

پاسخ : دماسنج با lm335

سلام
دوست عزیز پایه های avcc و aref رو اتصال دادی؟؟؟ اگه نه بدید احتمالا مشکلتون حل میشه