global [dist]

constants
   [[porta 5][porta-ddr $85]
    [portb 6][portb-ddr $86]]

to transmit :n
   ifelse :n = 0
   [ repeat 14 [clearbit 7 portb] ]
   [ repeat 14 [setbit 7 portb]   ]   
end

to strobe-none
   transmit 0
   transmit 1
   transmit 0
   transmit 1
   transmit 0
   transmit 1
end

to strobe-far
   transmit 0
   transmit 0
   transmit 1
   transmit 1
   transmit 0
   transmit 1
end

to strobe-near
   no-op no-op no-op no-op no-op no-op
   transmit 1
   transmit 1
   transmit 0
   transmit 0
   transmit 1
   transmit 0
end

to sample-signal
  clearbit 7 portb-ddr
  setbit 0 porta-ddr
  setbit 1 porta-ddr

  wait 1
  repeat 25
  [
	transmit 0
	transmit 1
  ]
  loop[
	setdist (read-ad 0)

	ifelse dist < 120
	  [strobe-none]
	  [
	    ifelse dist > 223
	      [strobe-near]
	      [strobe-far]
	  ]
    ]
    
end