--> Temperature controlled fan

This project gives you a simple temperature controlled fan. If the difference between real temperature and the user temperature is high then the fan will run at full speed and if the difference is low then the fan will rotate at slow speed. The speed of the fan varies with the temperature.
The user can enter the temperature limit through the keypad.
The speed of the fan is adjusted by using the PWM.


circuit diagram -->

 

  

bascom code -:-->  

'--------------------------------main-------------------------------------------

$regfile = "m16def.dat"
$crystal = 1000000
'-------------------------------lcd---------------------------------------------
'rs=pinb.6,e=pinb.0,db4=pinb.2,db5=pinb.3,db6=pinb.4,db7=pinb.5
Config Lcd = 16 * 2
Config Lcdpin = Pin , Rs = Pinb.0 , E = Pinb.1 , Db4 = Pinb.2 , Db5 = Pinb.3 , Db6 = Pinb.4 , Db7 = Pinb.5

'-------------------------------key board---------------------------------------
Config Kbd = Portc
'Use the following code to disable JTAG
Mcusr = &H80
Mcusr = &H80
'--------------------------------pwm--------------------------------------------
Config Timer1 = Pwm , Pwm = 10 , Compare A Pwm = Clear Up , Compare B Pwm = Clear Down , Prescale = 1
 Start Timer1
 '--------------------------------dim-------------------------------------------
 'a,b  for keyboard, c for chek , d for pwm
 Dim A As Word , B As Word , C As Word , D As Word , Tanzim As Byte , E As Byte
 Dim Lop As Byte
 Dim Dama As Byte , Lm35 As Word , Motor As Word
 '--------------------------------adc-------------------------------------------
 Config Adc = Single , Prescaler = Auto , Reference = Avcc
 Start Adc
 '--------------------------------main------------------------------------------
 Config Pind.4 = Output
 Config Pind.5 = Output
 '------------------------------------------------------------------------------
               A = 0
               B = 0
               Cursor Off
               Cls
               Locate 1 , 5
               Lcd "Hello"
               Wait 2
               Cls

 Main:
                Locate 1 , 1
                Lcd "Intern number    "
                 Locate 2 , 1
                Lcd "                 "
                Compare1a = 1
                Compare1b = 1

Rool:


               A = Getkbd()
               If A = 16 Then Goto Rool

                A = A + 1
               Select Case A :

               Case 1 To 3:

               Case 4:
               Cls
               Lcd "f1"
Goto Rool

               Case 5 To 7 :
               A = A - 1

               Case 8:
               Cls
               Lcd "f2"
 Goto Rool


               Case 9 To 11:
               A = A - 2


               Case 12:
               Cls
               Lcd "f3"
 Goto Rool
               Case 13:
               Cls
               Lcd "start"
               Wait 1
               Goto Lm35

               Case 14:
               A = 0

               Case 15:
               B = 0
               A = 0
               Cls
               Goto Main

               Case 16:
               Cls
               Lcd "f4"
 Goto Rool
               End Select

Tanzim3:
               B = B * 10
               A = A + B
               B = A

               Cls
               Locate 1 , 1
               Lcd B ; "          "
               Locate 2 , 1
               Lcd "push start set"

Lop:
               Lop = Getkbd()
               If Lop <> 16 Then Goto Lop
               Goto Rool

'-------------------------------------------------------------------------------

Lm35:

            Lm35 = Getadc(0)
            Waitms 10
            Lm35 = Lm35 / 2

            A = Getkbd()
            A = A + 1
            If A = 15 Then Goto Stops

            Locate 1 , 1
            Lcd "TEMPERATURE= " ; Lm35 ; "c  "

            If Lm35 =< B Then
            Compare1a = 1
            Compare1b = 1
            Motor = 0
            Locate 2 , 1
            Lcd "Set=" ; B ; "  pwm=" ; Motor ; "             "
            Goto Lm35
            End If


            If Lm35 > B Then
            D = Lm35 - B
            Gosub Motor1
            End If

           Goto Lm35
           Motor1:

            Motor = D * 100
            Motor = Motor + 50

            If Motor > 1022 Then
            Motor = 1023
            Locate 2 , 1
            Lcd "Set=" ; B ; "  pwm=fast                 "
            End If

            If Motor =< 1022 Then
            Locate 2 , 1
            Lcd "Set=" ; B ; "  pwm=" ; Motor ; "             "
            End If

            Compare1a = Motor
            Compare1b = Motor

Download the code from here
Download the ckt diagram  from here