'********************************************************
' ir_analysis.bas
' Program to analize output from infrared sensor modules 
' PicBasic Pro Compiler 
'********************************************************

trisa = %11111111                   ' set porta to inputs
trisb = %00001100                   ' set portb pins 2 & 3 to inputs

temp     var byte                   ' initialize variables
ir_left  var byte
ir_right var byte
l_count  var byte
r_count  var byte
l_threshold var byte
r_threshold var byte
num_samples var byte

num_samples = 30                     ' number of samples taken per i.r. module
l_threshold = 15                     ' noise floor threshold for left detector
r_threshold = 15                     ' noise floor threshold for right detector

start:

      gosub infrared        ' get sensor values from infrared subroutine

      if ir_left = 1 then                           ' if left detector senses an object then 
          high portb.1                              ' turn on left LED
          sound portb.4,[130,1,90,2,100,1,110,2]    ' output left insect noise
      else
          low portb.1                                
      endif                
      
      if ir_right = 1 then                          ' if right detector senses an object then 
          high portb.0                              ' turn on right LED
          sound portb.4,[140,1,120,2,110,1,100,2]   ' output right insect noise
      else
          low portb.0
      endif

goto start 

infrared:

l_count = 0
r_count = 0
ir_left = 0
ir_right = 0

         for temp = 1 to num_samples       ' take 30 samples per detector
             
             if portb.2 = 0 then           ' if left module senses an object
                l_count = l_count + 1      ' increase the left count
             endif
             
             if portb.3 = 0 then           ' if left module senses an object
                r_count = r_count + 1      ' increase the right count
             endif
         
         next
         
         if l_count >= l_threshold then     ' if left count is greater than the threshold
            ir_left = 1                     ' then an object was sensed with left detector
         endif
         
         if r_count >= r_threshold then     ' if right count is greater than the threshold
            ir_right = 1                    ' then an object was sensed with right detector
         endif
                                            
return                                      ' return to main program

end