symbol RightDetect = B0
symbol LeftDetect = B1
symbol distance = B2
symbol counter = B3
symbol RightDistance = B4
symbol LeftDistance = B5
symbol left = 1
symbol right = 4

Proximity_Detect:
  RightDistance = 7
  LeftDistance = 7
  for counter = 1 to 6
  
CheckRight:
    if RightDistance < 7 then CheckLeft 
    low right
    high left
    gosub Flash
    RightDetect = pin3            '0 = detect, 1 = no detect
    pwmout 2 off
    pause 2
    if RightDetect = 1 then CheckLeft
    RightDistance = counter
    
CheckLeft:
    if LeftDistance < 7 then FinishCheck 
    low left
    high right
    gosub Flash
    LeftDetect = pin3             '0 = detect, 1 = no detect
    pwmout 2 off
    pause 2
    if LeftDetect = 1 then FinishCheck
    LeftDistance = counter  

FinishCheck:
    if LeftDistance < 7 then IsRight7
    goto Repeat_Flash

IsRight7:    
    if RightDistance < 7 then Report    

Repeat_Flash:
  next           
  
Report:
'  sertxd (13,10,"L",#LeftDistance,"R",#RightDistance)
  serout 0,T1200_4,(255,"L",LeftDistance,"R",RightDistance)
  goto Proximity_Detect  
  
Flash:
  if counter > 1 then Check33
  gosub kHz32
  goto End_Flash
  
Check33:  
  if counter > 2 then Check34
  gosub kHz33
  goto End_Flash
  
Check34:  
  if counter > 3 then Check35
  gosub kHz34
  goto End_Flash
  
Check35:  
  if counter > 4 then Check36
  gosub kHz35
  goto End_Flash
  
Check36:  
  if counter > 5 then Check37
  gosub kHz36
  goto End_Flash
  
Check37:  
  if counter > 6 then Check38
  gosub kHz37
  goto End_Flash
  
Check38:  
  gosub kHz38
  
End_Flash:
  return  

kHz38:  
  pwmout 2,25,53    ' 14 inches
  return 
 
kHz37:
  pwmout 2,26,54    ' 10 inches 
  return   
 
kHz36:
  pwmout 2,27,56    ' 9 inches 
  return   
 
kHz35:
  pwmout 2,28,57    ' 6 inches
  return   
  
kHz34:
  pwmout 2,28,59    ' 5 inches  
  return  
    
kHz33:              
  pwmout 2,29,61    ' 3 inches
  return   
  
kHz32:              
  pwmout 2,30,63    ' 2 inches   
  return