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This is a work in progress. (It now works!)

I setup the pwmout to provide close enough to 39.2 kHz and feed that into an AND gate. The other input of the AND gate is an output from the picaxe. I send T1200 signals out from the output and into the AND gate which results in a 39.2 Khz carrier modulated at 1200 baud. Great so far!

BUT! The Wowee protocol wants a header that looks like this %11111111 followed by a time spaced pattern where a high is 0001 and a low is 01. If I code up a typical pattern for say “Walk forward” or $86 it looks like %11111111,%000101010,%01010001,%00010100

It took me the longest time, but I think I know what isn’t working. Looking at the output on a scope there is a single low to high transition between each 8 bit transmission. This is messing up all my timing. I assume this is the “1 stop bit” in the 8n1. I don’t know where to go from here. Maybe if I sleep on it I will have some ideas in the morning. Otherwise, I will have to give up on the Picaxe for this project.

UPDATE:

After learning that the V2 protocal is 12 bits long, (From building a receiver and tying it to a scope) and getting an idea from Hippy on the Picaxe forum the project is now working. Here is the code

• ‘RoboSapien IR control using picaxe 08M
  ‘Pass commands at 4800 baud 8N1 from your terminalsetfreq m8′IR is modulated by channel 1
  symbol IR = 1
  ‘This is a dummy variable to make pulsout work
  symbol dum = 4′These are values to make the timing work
  symbol duration = 88
  symbol start = 1203
  symbol highbit = 560
  ’start the pwm module
  pwmout 2,50,100
  main:
  low ir
  ‘refresh the pwm module
  pwmout 2,50,100
  pause 50
  ‘Get a value from the terminal
  serin 4,N2400,b0
  pause 10′Init and WAKEUP sequence
  high IR
  pulsout dum,start
  ‘RSV2 header is always 0011 0
  low IR
  pulsout dum,duration
  high IR
  pulsout dum,duration
  ‘This bit is low 0
  low IR
  pulsout dum,duration
  high IR
  pulsout dum,duration
  ‘This bit is high 1
  low IR
  pulsout dum,highbit
  high IR
  pulsout dum,duration
  ‘This bit is high 1
  low IR
  pulsout dum,highbit
  high IR
  pulsout dum,duration
  ‘END HEADER

  ‘logic

  if bit7 = 0 then
  gosub lowsignal
  else
  gosub highsignal
  endif
  if bit6 = 0 then
  gosub lowsignal
  else
  gosub highsignal
  endif
  if bit5 = 0 then
  gosub lowsignal
  else
  gosub highsignal
  endif
  if bit4 = 0 then
  gosub lowsignal
  else
  gosub highsignal
  endif
  if bit3 = 0 then
  gosub lowsignal
  else
  gosub highsignal
  endif
  if bit2 = 0 then
  gosub lowsignal
  else
  gosub highsignal
  endif
  if bit1 = 0 then
  gosub lowsignal
  else
  gosub highsignal
  endif
  if bit0 = 0 then
  goto finallowsignal
  else
  goto finalhighsignal
  endif

  goto main

  highsignal:
  ‘This bit is high 1
  low IR
  pulsout dum,highbit
  high IR
  return

  lowsignal:
  ‘This bit is low 0
  low IR
  pulsout dum,duration
  high IR
  return

  finalhighsignal:
  ‘This bit is high 1
  low IR
  pulsout dum,highbit
  high IR
  pulsout dum,2
  goto main

  finallowsignal:
  ‘This bit is low 0
  low IR
  pulsout dum,duration
  high IR
  pulsout dum,2
  goto main

A quick note on the IR transmitter stage. I adapted this from the robotroom. He has a nice writeup on using a 555 to drive a IR transmitter. However, the PicAxe pwmout gives a reasonable alternative.

Finally just for fun I tried taking pictures of the oscilloscope screen with the digital camera. This is not of any particular signal, but it works better then I expected! I remember using a special adapter to take Polaroids of Oscope screens back in the day…..

Because this project was such a pain, I bought a new scope written about elsewhere. I love it! Here is a wowee signal on the new scope. Where was this a few weeks ago! Note that the 0011 header followed by the device command. In this case it is 10010000 This corresponds to the master program command (Or the D button on the remote)