' intruder_alarm.bas
' author: kerwin lumpkins, 2/25/04
' this program drives an Atmel ATiny26 IC mounted on the Intruder Alarm project
' board to monitor a photoreflective sensor connected to Pin B4.  This sensor
' should look at a white block mounted on a door.  When the alarm is armed and
' the door is opened, the sensor output voltage will change when the white
' block is not there to reflect its light.  The A/D converter on B4 will detect
' this change in voltage past the triggervalue (must be calibrated for each
' sensor) and enter the prealarm state where the user must enter a 3 digit code
' before a timeout expires.  If he/she does not sucessfully enter the code (1
' try only) then the alarm goes off.

Declare Sub Flvald
Dim Flval As Byte

' This program operates as a state machine.  States are
Const Disarmed = 0
Const Armed = 1
Const Triggered = 2
Const Alarm = 3
Const Program = 4

' SW4 or the program switch is on PB6 which is INT0.  So while the system is in
' the armed (not triggered) state, the user can enter programming mode and change the code.

' set portb inputs on pb1,2,3 (code switches) b4 (sensor), all others output
' note that by default the program switch on b6 is disabled
Ddrb = &B10100000
Ddra = &B11111111

Config Adc = Single , Prescaler = Auto

Dim Switches As Byte
Dim State As Byte
Dim Code_entered(3) As Byte
Dim Code_pgmd(3) As Byte
Dim Cnt As Byte
Dim Hump As Byte
Dim Sw1 As Byte , Sw2 As Byte , Sw3 As Byte
Dim Sensor As Word
Dim Timcnt As Byte
Dim Trig As Byte

Const Triggervalue = &H333

Led_red Alias Porta.6
Buzzer Alias Porta.4
Led_yel Alias Porta.7

A3 Alias Porta.3
A2 Alias Porta.2
A1 Alias Porta.1
A0 Alias Porta.0

'default code
Code_pgmd(1) = 2
Code_pgmd(2) = 1
Code_pgmd(3) = 3

Main:
' state ------ DISARMED -------
State_disarmed:
State = Disarmed
' you can end up here after entering code and disarming the unit
' so we want to disable the timer before it fires
Disable Interrupts
Disable Timer0

' user feedback to show that unit is in disarmed state
Led_red = 0
Led_yel = 0
Wait 1


' feedback the programmed code
   If Code_pgmd(1) = 1 Then Flval = 1
   If Code_pgmd(1) = 2 Then Flval = 2
   If Code_pgmd(1) = 3 Then Flval = 3
   Gosub Flvald
   If Code_pgmd(2) = 1 Then Flval = 1
   If Code_pgmd(2) = 2 Then Flval = 2
   If Code_pgmd(2) = 3 Then Flval = 3
   Gosub Flvald
   If Code_pgmd(3) = 1 Then Flval = 1
   If Code_pgmd(3) = 2 Then Flval = 2
   If Code_pgmd(3) = 3 Then Flval = 3
   Gosub Flvald


' wait 10 seconds from reset to arm the system

Enable Interrupts
Enable Int0

On Int0 State_program

Wait 6


' state ----- ARMED -----
State_armed:
State = Armed

' turn off interrupt so you can't enter program mode to get around code entry
Disable Interrupts
Disable Int0

Start Adc
Led_yel = 1
Led_red = 0
Wait 1
Trig = 0

While Trig = 0
   Sensor = Getadc(7)
   A3 = Sensor.9
   A2 = Sensor.8
   A1 = Sensor.7
   A0 = Sensor.6
   Waitms 10
   If Sensor > Triggervalue Then Trig = 1
Wend

Goto State_triggered


' state ----- TRIGGERED -----
State_triggered:
   State = Triggered
   Led_red = 1
   Led_yel = 0

Stop Adc
Ddrb = &B10100000
Cnt = 1

   'start the countdown timer
Config Timer0 = Timer , Prescale = 1024
On Ovf0 Tim0_isr

Enable Timer0
Enable Interrupts


' start the 10 second timer and watch for button presses until it fires

Nobtn:

   Waitms 1
   Switches = Pinb And &H0E
   Shift Switches , Right , 1

   If Switches = 3 Then Goto Btn3
   If Switches = 5 Then Goto Btn2
   If Switches = 6 Then Goto Btn1

   'any other condition
   Goto Nobtn

Btn1:
   Led_yel = 1
   Code_entered(cnt) = 1

   ' wait for button to be released
   Sw1 = Pinb And &H02
   While Sw1 = 0
    Sw1 = Pinb And &H02
   Wend
   Waitms 1

   Led_yel = 0

   Incr Cnt
   If Cnt = 4 Then Goto Checkcode
   ' if not, then go get next button press

   Goto Nobtn

Btn2:
   Led_yel = 1
   Code_entered(cnt) = 2

   ' wait for button to be released
   Sw2 = Pinb And &H04
   While Sw2 = 0
      Sw2 = Pinb And &H04
   Wend
   Waitms 1

   Led_yel = 0
   Incr Cnt
   If Cnt = 4 Then Goto Checkcode
   ' if not, then go get next button press

   Goto Nobtn

Btn3:
   Led_yel = 1
   Code_entered(cnt) = 3

   ' wait for button to be released
   Sw3 = Pinb And &H08
   While Sw3 = 0
      Sw3 = Pinb And &H08
   Wend
   Waitms 1

   Led_yel = 0
   Incr Cnt
   If Cnt = 4 Then Goto Checkcode
   ' if not, then go get next button press

   Goto Nobtn

' jump here if 3 button presses detected
Checkcode:
   Led_yel = 0
   Wait 1

 Check1:
   If Code_entered(1) = Code_pgmd(1) Then Goto Check2 Else Goto State_alarm
   'Led_yel = 1
   'Waitms 500
   'Led_yel = 0
   'Waitms 500
Check2:
   If Code_entered(2) = Code_pgmd(2) Then Goto Check3 Else Goto State_alarm
   'Led_yel = 1
   'Waitms 500
   'Led_yel = 0
   'Waitms 500
Check3:
   If Code_entered(3) = Code_pgmd(3) Then Goto State_disarmed Else Goto State_alarm

   ' else the code was correct
   Goto State_disarmed




' *********************************************
State_program:
' turn off the INT0 interrupt so you can't start this state
' over again by mistake
Disable Interrupts
Disable Int0

Led_red = 1
Led_yel = 1

Cnt = 1

Nobtnpgm:

   Waitms 1
   Switches = Pinb And &H0E
   Shift Switches , Right , 1

   If Switches = 3 Then Goto Btn3pgm
   If Switches = 5 Then Goto Btn2pgm
   If Switches = 6 Then Goto Btn1pgm

   'any other condition
   Goto Nobtnpgm

Btn1pgm:
   Led_yel = 1
   Code_pgmd(cnt) = 1

   ' wait for button to be released
   Sw1 = Pinb And &H02
   While Sw1 = 0
    Sw1 = Pinb And &H02
   Wend
   Waitms 1

   Led_yel = 0

   Incr Cnt
   If Cnt = 4 Then Goto Storecode
   ' if not, then go get next button press

   Goto Nobtnpgm

Btn2pgm:
   Led_yel = 1
   Code_pgmd(cnt) = 2

   ' wait for button to be released
   Sw2 = Pinb And &H04
   While Sw2 = 0
      Sw2 = Pinb And &H04
   Wend
   Waitms 1

   Led_yel = 0
   Incr Cnt
   If Cnt = 4 Then Goto Storecode
   ' if not, then go get next button press

   Goto Nobtnpgm

Btn3pgm:
   Led_yel = 1
   Code_pgmd(cnt) = 3

   ' wait for button to be released
   Sw3 = Pinb And &H08
   While Sw3 = 0
      Sw3 = Pinb And &H08
   Wend
   Waitms 1

   Led_yel = 0
   Incr Cnt
   If Cnt = 4 Then Goto Storecode
   ' if not, then go get next button press

   Goto Nobtnpgm

Storecode:

Goto State_disarmed





' state ----- ALARM  ALARM  ALARM ------
State_alarm:

   Cnt = 1
   ' loop until powered off, sound buzzer and flash LED on/off
   While Cnt = 1
      Led_red = 1
      Buzzer = 1
      Waitms 100

      Led_red = 0
      Buzzer = 0
      Waitms 100
   Wend



End

' timer 0 Interrupt Service Routine
Tim0_isr:
   Incr Timcnt
   If Timcnt > 25 Then Goto Timerfired
   Return

Timerfired:
   Disable Interrupts
   Goto State_alarm


' ^^^^^^^^^^^  subroutine ^^^^^^^^^^^^^^^
Sub Flvald:
   For Hump = 1 To Flval
      Led_yel = 1
      Waitms 200
      Led_yel = 0
      Waitms 200
   Next

   Wait 2
End Sub Flvald