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Subject: 
Re: IR camera?
Newsgroups: 
lugnet.robotics
Date: 
Sun, 14 Feb 1999 17:43:24 GMT
Viewed: 
1669 times
  
Good point, I also had the brief idea to construct something like a IR-mirror
which scatters the IR but with only 2 motors the mechanics become a nightmare.

I looked into the palm III and its actually more difficult than initially
thought:
Lego is transmitting data with the help of a carrier frequency, meaning a bit is
signaled by the existence/absence of 1/2400 sec of 38.4khz IR bursts. Palm
however is using IrDA which works with timed IR pulses only and there seems to
be a pulse length limiter built into the PalmIII sending HW.

The solution as demonstrated by Remote for PalmIII seems to be the IrDA sampling
of the lego bursts as bytes and translating these into bits. Meaning reading the
Logo bits as IrDA bytes (of a higher frequency) and then assembling the Lego
bytes out of a series of IrDA data. For that, one has to circumvent the std IrDA
framing (leading byte, trailing byte and CRC checksum).

I am actually talking to the developer of Remote for PalmIII and in the next
version there seems to be a library which does this nasty translation for you.

I will post my experience on the news group while I am going forward on this.

Cheers
     Reimer



lego-robotics@crynwr.com wrote:

Actually, you don't need true line of sight from the RCX to the tower. The
IR light is sufficiently strong enough that reflections from walls,
etc. can still control the RCX and vice versa. (Try this with the RCXCC
"joystick" utility.) As for the PalmIII, I've got one of those and would
love for a utility like RCXCC ported over.

Linh

Hi,
yes, I actually had the same idea: use the light sensor on a robot as a
crude mobile low-quality camera, which
sends back scan-lines to the PC via datalog. however, thinking about the
needed IR transmission and the
line-of-sight precondition (you want to send back scan-lines even while
scanning orthogonal to the IR transmission line), led me to another idea.
Given the fact that the physical and logical format of the IR is known, it
should prove possible to use a PalmIII
to communicate with the RCX. So you could attach the Pilot to the robot
and have him control everything.

What do you guys think?

__Reimer



lego-robotics@crynwr.com wrote:

I'm not sure how feasible this would be, but has anyone considered
making a digital camera using the light sensor? All you'd need is
a focusing mechanism with lenses/mirrors, and a couple of motors to
scan left to right and up and down. Sounds easy enough. :)
You could just upload one pixel at a time to the pc via the IR port.
Would this be the "ultimate" project for the RCX? Or maybe a
project to measure the speed of light, a torsion balance, or a
nifty handy-dandy little RCX cyclotron? OK, maybe not a cyclotron.
Maybe a spectrometer. Just wondering what you all think the ultimate
project might be. Personally, I'd like to eventually do an RCX/PC
AI or artificial life project that allows the PC to become self-aware
by investigating and manipulating its environment through the RCX.

Linh
--
Did you check the web site first?: http://www.crynwr.com/lego-robotics



Message has 1 Reply:
  datalog in legOS
 
I'm sure this has been discussed before, but I can't seem to find it in the archives- how can I write to the datalog in legOS? Thanks in advance. Luis ###...### "They call the faithful to their knees to hear the softly spoken magic spell:" "There's (...) (26 years ago, 15-Feb-99, to lugnet.robotics)

Message is in Reply To:
  Re: IR camera?
 
Actually, you don't need true line of sight from the RCX to the tower. The IR light is sufficiently strong enough that reflections from walls, etc. can still control the RCX and vice versa. (Try this with the RCXCC "joystick" utility.) As for the (...) (26 years ago, 14-Feb-99, to lugnet.robotics)

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