' PicBasic Pro program to read the signal
' from an IR photodiode, send it to serial out,
' and light up an LED when a signal is found.
' Connect analog input to channel-0 (RA0)

' Define ADCIN parameters
DEFINE  ADC_BITS        10     ' Set number of bits in result
DEFINE  ADC_CLOCK       3       ' Set clock source (3=rc)
DEFINE  ADC_SAMPLEUS    50      ' Set sampling time in uS

ADCvar  VAR WORD                ' Create variable to store result

TRISA = %11111111       ' Set PORTA to all input
ADCON1 = %10000010      ' Set PORTA analog and right justify result
Pause 500               ' Wait .5 second

main:
      ADCIN 0, ADCvar       ' Read channel 0 to adval
      serout2 PORTD.7, 16468, [DEC ADCvar, 13, 10] ' print it to serial out,
                             ' with linefeed and carriage return (10, 13)
 if ADCvar > 0 then          ' we have detected an IR signal
  high portd.1               '  light up the first segment of the bar LED graph
 endif
 if ADCvar > 50 then          ' if the signal is stronger, light up another bar
   high portd.0
 endif
 if ADCvar > 100 then         ' if the signal is stronger still, light another
   high portc.3
 endif
 if ADCvar > 150 then         'etc
   high portc.2
 endif
 if ADCvar > 200 then          'etc
   high portc.1
 endif
 if ADCvar > 250 then          'etc
   high portc.0
 endif

 if ADCvar = 0 then             'start turning leds off when the signal dies
  low portd.1
 endif
 if ADCvar < 50 then
   low portd.0
 endif
 if ADCvar < 100 then
   low portc.3
 endif
 if ADCvar < 150 then
   low portc.2
 endif
 if ADCvar < 200 then
   low portc.1
 endif
 if ADCvar < 250 then
   low portc.0