Hi Guys
I am starting a project where I have to transmit a signal from a HV area
down to the control unit. and the way that I have to do it is by using the
existing fibre-optics that are already installed from an obsolete system
previously removed. I do not want to use V/F & F/V converters as that was
not a very good solution in the past, so I am looking into converting the
signal to a 16bit digital signal and then transmit it serially which seems
strait forward enough. The problems are:

        - I would like to use one fibre only if possible
        - bandwidth needs to be min 100KHz, ideally 200KHz
        - I need to be able to disconnect the receiver and then connect it
again and automatically synchronize transmission
        - require error detection i.e. checksum, link failed.

The fibres installed with the fibre-optics TX/RX can do 5MB/s which should
be enough, I do not think I can do it with the PIC as for 200KHz for 16bits
you need to be transmitting at around 4MHz. I will be using an ALTERA FPGA.
I can more or less see what to do to transmit the data ( get it into
digital, feed it to the FPGA as an 16 bit number and then shift it), but the
automatic synchronization and the error detection is a problem. By
synchronization I mean if I disconnect the receiver and connect it again and
it finds it self in the middle of a packet it will wait until it receives
the start of the next one before it considers it a full signal.

Any ideas will be welcome
thanks

best regards
                Luis



-----Original Message-----
From: Roland [mailto:jemelectric@MWEB.CO.ZA]
Sent: 24 February 2004 07:57
To: PICLIST@mitvma.mit.edu
Subject: Re: [PIC:] Serial IR Data Communication


Hi scott

Sounds like direction, and data collision, are going to be a problem.
Have you looked at the packet radio sites? Not for the radio, but for the
protocols. There is tons of stuff there, and I do remember seeing pic stuff
implememted.

http://www.packetradio.com/Radio-TNC%20Wiring%20Diagrams.htm
http://www.tapr.org/tapr/html/pktf.html

Regards
Roland

At 05:43 PM 23/02/04 -0800, you wrote:
>Hi All,
>
>Does anyone know of any good reference material (website, book, etc) on how
>to implement serial IR communication?  I'd like to be able to send bytes of
>data from one robot to another using something along the lines of a 38Khz
>receiver (Vishay TSOP1138 maybe) and an IR LED.  The target PIC would most
>likely be a 16F628.  I've searched the net and haven't been able to find a
>whole lot of information.  Rentron.com has a chip that will do this but I'd
>like to implement it directly into my robot's brain and I plan on making as
>many of these as I can so I can have them interact with each other.  Any
>help you can provide me with is greatly appreciated.
>
>Scott
>
>--
>http://www.piclist.com hint: The PICList is archived three different
>ways.  See http://www.piclist.com/#archives for details.
>
Regards
Roland Jollivet


JeM Electric cc
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