Re: TI-H: RCL - Radio Chat Link
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Thank you! I'm the original guy who posted crap about an RF link. I've been
fed up with brainless people asking what about this and that. My answer is
I DON'T KNOW SO SHUT UP! I applaud you.
Here's what I want to say in response to your list.
a) I'm trying to make an RF (Radio Frequency) link. It'll work just like
the link cable for sending everything, not just text. That way no special
software is needed. Just a box to plug in.
That's it.
/--------------------------------\
/ Travis Pettijohn \
/ primary: travisp@inil.com \
/ alternate: travisp@juno.com \
/ http://www.inil.com/users/travisp/ \
/------------------------------------------\
I assume no liability for any advice I give.
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> From: Laurits Søgaard Nielsen <CSN@dk-online.dk>
> To: Ti - Hardware <ti-hardware@lists.ticalc.org>
> Subject: TI-H: RCL - Radio Chat Link
> Date: Tuesday, November 05, 1996 8:50 AM
>
> If you are interested in helping with the creation of a RCL - Radio Chat
> Link!
>
> Then read the following:
>
> Here is what I think we should do:
>
> The link should be for 2 calcs in one room only!!!!
>
> The reason for this is:
>
> 1. The chat program must be limited in size, a 20 KB chat program simply
> won't work, (No place for the games!!). An error correcting, peer to peer
> network program would definately take up a looooot of space on the calc.
>
> 2. Since we would need it to be quiet (NO NOISE AT ALL) when we were
> broadcasting. We would have to use FM (Frequency Modulation) for
> transmitting, since that is virtually noiseless (When the signal is
> powerfull enough).
>
> 3. The next problem is that an FM reciever ONLY picks up the strongest
> signal. I.e. mixing 10 signals over the same frequency is impossible, as
> only the most powerful signal would be recieved. Therefore the link would
> require 10 transmitters and 10 recievers to work properly.
>
> 4. 10 Transmitters would broadcast virtually "everywhere", making
detection
> easy at an exam. (The reason for not using the earpiece and the walkie is
> that it looks kind a strange on the table at the math exam. A calculator
> looks a little more "normal")
>
> We would in my opinion have to make the link to be used with ZShell, (Not
> TI-OS)
>
> The reason for that is that only 1 transmitter should be used. (No room
in
> the calc for 2 transmitters and 2 recievers, only room for 1 of each)
>
> That one transmitter should have a switch so that it would be possible to
> use 2 frequencies. If you only have 1 frequency, you wouldn't be able to
> talk to transmitting calcs with your frequency.
>
> The transmission distance could be anything from 1 meter to 300-400
meters.
> And don't bullshit me. I've built my own bugs, the best one went as far
as
> 1000 meters. But that was also an SMD (Surface mount) bug.
>
> It would be cool if somebody would help with the following.
>
> Creating the electronics.
> Setting up a hompage for the RCL
> Do the programming in ZShell
> Testing the link
>
> We could assign one or more persons to do each thing.
>
> PLEASE: If you don't know shit about electronics don't mail telling that
> this is wrong, or asking for a network. I'm not capable of making that,
and
> not interested either! If you found a mistake and you do know what you
are
> talking about, feel free to tell it. Any relevant ideas or comments are
> also appreciated.
>
> If you care to work with me on this project. Then mail me:
> Laurits <CSN@dk-online.dk>
>
>
> Methods for the transmitting and recieving:
>
> The transmitter could be made with a crystal or a coil and capacitor.
> I would prefer the crystal, as that is frequency stable.
>
> We could use either the carrier or a tone for "HIGH" and "LOW" signals
>
> No carrierwave = LOW
> Carrierwave = HIGH
>
> Tone = HIGH
> No tone = LOW
>
> If we use the tone we would need a multivibrator with a crystal to create
a
> low frequency (Maybe 20KHz). When the signal was recieved, a filter would
> allow only this frequency to pass. The frequency could then turn a
> transistor high or low.
> This method would be very tolerant to incoming noise from the calc.
>
> Try sitting with your calc next to a cheap radio, and mess with it.
You'll
> se what I mean. (If you have a CE calc. this probably won't affect the
> radio)
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