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Infrared Remote Control Code — Parallax Forums

Infrared Remote Control Code

MaxMax Posts: 13
edited 2006-08-01 19:48 in Robotics
Hey guys. I'm a counselor at a summer computer camp, and we offer Robotics as a course. One of the projects in this course is to hook up some IR receivers and use a remote to control the computer. I don't know if Parallax makes the remote or if it's proprietary, so here's a picture of it:

remote.jpg

Anyway, the way our camp gives us the code, the cars move in short bursts instead of continuously. I've been trying to optimize the code, but for the life of me I just cannot figure it out! Can anyone explain to me what in god's name is going on here?:

'Version 030217
'{$STAMP BS2}
'{$PBASIC 2.5}
'
'
''''''''''''''''
' main routine '
''''''''''''''''
DEBUG "Reset",CR

DO WHILE 1  'loop forever
  GOSUB getcode    'get remote signal code
  DEBUG ?receive  'display which code was pressed
                  'and then perform an action
  SELECT receive
    CASE 770
  'up button pressed
  FOR x = 0 TO 25
  PULSOUT 14, 750-150
  PULSOUT 15, 750+150
  PAUSE 20
  NEXT
    CASE 962
  'down button pressed
  FOR x = 0 TO 25
  PULSOUT 14, 750+150
  PULSOUT 15, 750-150
  PAUSE 20
  NEXT
    CASE 834
  'left button pressed
  FOR x = 0 TO 25
  PULSOUT 14, 750+150
  PULSOUT 15, 750+150
  PAUSE 20
  NEXT
    CASE 898
  'right button pressed
  FOR x = 0 TO 25
  PULSOUT 14, 750-150
  PULSOUT 15, 750-150
  PAUSE 20
  NEXT
    CASE 850
  'power button pressed
  END
    CASE 594
  'mute button pressed
  FREQOUT 1, 750, 1046 'C
  FREQOUT 1, 750, 1567 'G
  FREQOUT 1, 250, 1396 'F
  FREQOUT 1, 250, 1318 'E
  FREQOUT 1, 250, 1174 'D

  FREQOUT 1, 700, 2092 'C
  FREQOUT 1, 700, 1567 'G
  FREQOUT 1, 250, 1396 'F
  FREQOUT 1, 250, 1318 'E
  FREQOUT 1, 250, 1174 'D
  FREQOUT 1, 700, 2092 'C
  FREQOUT 1, 700, 1567 'G
  FREQOUT 1, 250, 1396 'F
  FREQOUT 1, 250, 1318 'E
  FREQOUT 1, 250, 1396 'F
  FREQOUT 1, 700, 1174 'D
    CASE 930
  'enter button pressed
  END
  CASE 930
 endcase:
 END
  ENDSELECT:
    LOOP


''''''''''''''''''''''''''''''''''''''''''''
'subroutine for scanning for remote signal '
' do not change '
' '
' hook up IR receiver to pin 0 '
''''''''''''''''''''''''''''''''''''''''''''
getcode:
  RECEIVE VAR Word
  COPY VAR Word
  IR_IN CON 0 'change this number
  IR_Pin VAR IN0 'and this number
  buffer VAR Word(4)
  x VAR Byte
  bitcount VAR Nib
  beats VAR Nib
'  spender VAR Bit 'max
  copy = receive
'  spender = 0

wait_for_clear:
  IF IR_PIN = 0 THEN wait_for_clear
  IF IR_PIN = 0 THEN wait_for_clear
  IF IR_PIN = 0 THEN wait_for_clear
  IF IR_PIN = 0 THEN wait_for_clear
  IF IR_PIN = 0 THEN wait_for_clear

wait_for_signal:
  IF IR_PIN = 1 THEN wait_for_signal
  ' why can't this be a part of the for loop?
  ' is it a timing problem?  when I remove all of these
  ' and make them part of the for loop, it no longer reads all
  ' 64 bits, even though the foor loop goes from 1 to 63
  ' (i manually read the first one)

  buffer.BIT0(0) = ~IR_PIN
  buffer.BIT0(1) = ~IR_PIN
  buffer.BIT0(2) = ~IR_PIN
  buffer.BIT0(3) = ~IR_PIN
  buffer.BIT0(4) = ~IR_PIN
  buffer.BIT0(5) = ~IR_PIN
  buffer.BIT0(6) = ~IR_PIN
  buffer.BIT0(7) = ~IR_PIN
  buffer.BIT0(8) = ~IR_PIN
  buffer.BIT0(9) = ~IR_PIN
  buffer.BIT0(10) = ~IR_PIN
  buffer.BIT0(11) = ~IR_PIN
  buffer.BIT0(12) = ~IR_PIN
  buffer.BIT0(13) = ~IR_PIN
  buffer.BIT0(14) = ~IR_PIN
  buffer.BIT0(15) = ~IR_PIN
  buffer.BIT0(16) = ~IR_PIN
  buffer.BIT0(17) = ~IR_PIN
  buffer.BIT0(18) = ~IR_PIN
  buffer.BIT0(19) = ~IR_PIN
  buffer.BIT0(20) = ~IR_PIN
  buffer.BIT0(21) = ~IR_PIN
  buffer.BIT0(22) = ~IR_PIN
  buffer.BIT0(23) = ~IR_PIN
  buffer.BIT0(24) = ~IR_PIN
  buffer.BIT0(25) = ~IR_PIN
  buffer.BIT0(26) = ~IR_PIN
  buffer.BIT0(27) = ~IR_PIN
  buffer.BIT0(28) = ~IR_PIN
  buffer.BIT0(29) = ~IR_PIN
  buffer.BIT0(30) = ~IR_PIN
  buffer.BIT0(31) = ~IR_PIN
  buffer.BIT0(32) = ~IR_PIN
  buffer.BIT0(33) = ~IR_PIN
  buffer.BIT0(34) = ~IR_PIN
  buffer.BIT0(35) = ~IR_PIN
  buffer.BIT0(36) = ~IR_PIN
  buffer.BIT0(37) = ~IR_PIN
  buffer.BIT0(38) = ~IR_PIN
  buffer.BIT0(39) = ~IR_PIN
  buffer.BIT0(40) = ~IR_PIN
  buffer.BIT0(41) = ~IR_PIN
  buffer.BIT0(42) = ~IR_PIN
  buffer.BIT0(43) = ~IR_PIN
  buffer.BIT0(44) = ~IR_PIN
  buffer.BIT0(45) = ~IR_PIN
  buffer.BIT0(46) = ~IR_PIN
  buffer.BIT0(47) = ~IR_PIN
  buffer.BIT0(48) = ~IR_PIN
  buffer.BIT0(49) = ~IR_PIN
  buffer.BIT0(50) = ~IR_PIN
buffer.BIT0(51) = ~IR_PIN
buffer.BIT0(52) = ~IR_PIN
buffer.BIT0(53) = ~IR_PIN
buffer.BIT0(54) = ~IR_PIN
buffer.BIT0(55) = ~IR_PIN
buffer.BIT0(56) = ~IR_PIN
buffer.BIT0(57) = ~IR_PIN
buffer.BIT0(58) = ~IR_PIN
buffer.BIT0(59) = ~IR_PIN
buffer.BIT0(60) = ~IR_PIN
buffer.BIT0(61) = ~IR_PIN
buffer.BIT0(62) = ~IR_PIN
buffer.BIT0(63) = ~IR_PIN

  receive = 0
  bitcount = 0
  cutoff CON 3 'length of pulse to count as 1
FOR x = 1 TO 63
  ' why does this break when the following line and the buffer negations are removed?
  ' is this just to spend a clock cycle?  I tried removing the tildes and spending the
  ' clock cycle a different way, and it didn't work
  buffer.BIT0(x) = ~buffer.BIT0(x)
  IF buffer.BIT0(x) = 1 THEN
    IF buffer.BIT0(x-1) = 0 THEN
      DEBUG "0 to 1, end of pulse.", CR
      '0 to 1 transition (end of pulse)
      beats = (beats - cutoff) >> 15
      DEBUG "Shifted beats: ", DEC beats, " BIN: ", BIN beats,CR
      receive = (receive << 1) | beats
      DEBUG "Received: ", DEC receive, " BIN: ", BIN receive, CR
      bitcount = bitcount + 1
      DEBUG "Bitcount: ", DEC bitcount, " BIN: ", BIN bitcount, CR
    ENDIF
  ELSE
    DEBUG "Low. Beats: ", DEC beats, CR
    'pulse... count beats
    IF buffer.BIT0(x-1) = 1 THEN
      DEBUG "1 to 0, reset beats.", CR
      beats = 0
    ENDIF
    beats = beats + 1 'add a beat
  ENDIF
NEXT
' no idea why this is necessary
receive = ~(receive << (16 - bitcount & 15))
receive = receive >> 6
IF receive <> copy THEN getcode 'make sure code is received properly
RETURN

Comments

  • willthiswork89willthiswork89 Posts: 359
    edited 2006-07-30 09:16
    goto the parallax website and look for IR remote for the boebot. thats way way over complicated!
  • MaxMax Posts: 13
    edited 2006-07-31 18:18
    willthiswork, I've been fooling around with the BoeBot code and flipping through the pdf file provided on the site. However, i'm receiving some really strange and unexpected input from my debug statements. I'm running this code:

    ' {$STAMP BS2}
' {$PBASIC 2.5}

time      VAR   Word

DO
  PULSIN 0, 0, time
  IF time <> 0  THEN
    DEBUG DEC5 time, CR
  ENDIF
LOOP



    It just outputs the length of the received pulse. However, no matter what button is pressed on the remote, the SAME output seems to be generated. There's always something with in the range of 1200 and 1275, then something within the range of 300 and 400. For example, tapping left, up, right, down, generates this code:

    (left tapped)
    1258
    450
    1239
    477

    (up tapped)
    1257
    403
    1230
    451

    (right tapped)
    1258
    450
    1216
    482

    etc, etc.

    There's no discernable pattern emerging based on the button pressed. What gives? It's as if that bitwise code I posted (given to us from HQ) works some kind of strange hocus-pocus on the numbers to create order from chaos.

    confused...
  • willthiswork89willthiswork89 Posts: 359
    edited 2006-08-01 19:48
    it may have more bits, basically it sends a pulse ammount of time, those numbers youyr looking at it the time if im correct, alot of numbers are the same but there will always be a bit thats diofferent, like

    Up- 220,460,700,900
    Down-210,370,650,700

    now you can see that both of these a relatively the same, there are two below and two above 500, but if you continue reading the bits sent in ull notice that there will be one where it is high then 500 and one lower then 500. Continue reading the PDF and see if you figure anything out.
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