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Ok so i want to make an rf link system... Do i just attatch the wires to the input of the transciever and give it power? Or do i need another chip? And do i need a transciever for each wire, or will just one work? Thabks guys!
rcplanegy wrote:
Ok so i want to make an rf link system... Do i just attatch the wires to the input of the transciever and give it power? Or do i need another chip? And do i need a transciever for each wire, or will just one work? Thabks guys!
Welcome back to Cemetech! I must ask you to please try to be a bit more careful with your spelling and grammar; you look much more intelligent when you type properly, and it's easier to read and understand your posts. You need some interface hardware to connect an infrared receiver and transmitter to your calculator, and since it has two link lines, you'll need a pairs of transmitters and receivers for each calculator. One possible technique to send both lines at the same time would be to use polarizers to plane-polarize the infrared right in 90-offset planes.
Yeah sorry about the grammar, I have to use my little ipod, with its 3" keyboard. Thanks for the reply, but I wish to make a RF link, not infrared. Please view this link:

http://www.sparkfun.com/products/10154
Funnily enough, I got a pair of 433MHz RF links a bit over a year ago for Sparkfun Free Day, and I've never actually gotten to try them otu with my calculator. It'll be no easy feat, though; with about 99% certainty regular wired protocols like the TI-Link Protocol and CALCnet won't work perfectly, or will at least require more complex hardware for support.
So the infrared would be easier? I suppose my main fear is having to be too obvious and point the infrared transceivers directly at each other. I wanted to know if RF transceivers would work, because ive heard they CAN (not saying they always do) transmit through walls. Plus, you wouldnt need line of sight. Please correct me if Im wrong, but I'd think the extra hardware would be worth a less obvious, easier to use system. Thanks!
I think that it absolutely would be worth it to come up with a working RF solution, because wireless calculator linking has been thrown around and considered for so many years, and no one has actually come up with a cheap, workable solution that plenty of people can actually build. If you/we could succeed, there would be a lot of very happy calculator ethusiasts.
I suspect something like the digi XBee's would work nicely with this.

There's a mode that's serial data in at one end, and serial data out at the other, and they seem configurable with AT Commands.

Dave
rfdave wrote:
I suspect something like the digi XBee's would work nicely with this. There's a mode that's serial data in at one end, and serial data out at the other, and they seem configurable with AT Commands.

Dave
a, why did I never think of that? Zigbee would be a perfect solution to this, although I'm not sure it would have the throughput that an application like this needs.
You should be able to get a 100k to 200kbyte/sec through the channel. How fast does the TI serial connection run?

Also-Are there serial connectors on the 68k? How about an internal installation? Much nicer

Dave
rfdave wrote:
You should be able to get a 100k to 200kbyte/sec through the channel. How fast does the TI serial connection run?
Two bits at a time, since there are two lines that can change at most once per 11/15,000,000 seconds on the 15MHz calculators = 0.73us, or at very worst case 2.7mbps of data. I know that CALCnet and the TI serial protocol top out around 3-10kbps, so I'll have to see if they can live with 800-1600kbps bandwidth; I tend to think it might actually be feasible.

Quote:
Also-Are there serial connectors on the 68k? How about an internal installation? Much nicer

Dave
No, no serial connectors. Most of the calculators have quite a bit of room inside for internal installation, though.
The XBee pro documentation claims to support 115.2kbaud serial data in transparent mode, although I couldn't find any info on the buffer size. It looks like it supports standard RS-232 style serial, with 8n1 and CTS/RTS. I'd guess a small AVR plus a XBee on each end would give you a transparent serial link, and a mesh network would be possible without too much work.
Interesting post on chiphacker, claiming slower speeds in mesh apps

http://electronics.stackexchange.com/questions/6047/xbee-dropping-packets-and-actual-data-rate-lower-than-expected


Although this wasn't in transparent mode. I'll have to do some playing around with the ones I have to see about data rates.
You should definitely give it a try, rfdave; I'd be quite interested in hearing your results as far as seeing the feasibility of this before I grab some hardware. Also, you should still Introduce Yourself when you get a chance!
*one-week bump* Did you get a chance to try out your Zigbees to see what happens? Or is this more of a long-term project? Smile
This is going to be a more long term thing.
Nearer term tasks include buying a house Sad this may impact my longer term tasks as well....

I also need to scrounge another ti84, it seems that calculator to calculator chat is probably first target. I haven't played around much with TI calculators, so I need to get a little more familiar with them.
Ah, best of luck on the house-buying! That must be super-stressful. Sad Speaking of chatting, have you checked out CALCnet Chat by Merth and myself yet?

http://www.cemetech.net/news.php?id=436

KermMartian wrote:
Ah, best of luck on the house-buying! That must be super-stressful. Sad Speaking of chatting, have you checked out CALCnet Chat by Merth and myself yet?


Thanks, I'll take a look at it. I take it I have to install Doors as well?

Buying a house is moderately stressful, mainly it's finding the right one in a tight market. Sad
Yes, you will also have to install Doors CS 7, which can be found in the archives.
souvik1997 wrote:
Yes, you will also have to install Doors CS 7, which can be found in the archives.
This. Chat works via globalCALCnet (if your network is connected to gCn) to also connect to IRC, specifically #cemetech on Efnet.
KermMartian wrote:
souvik1997 wrote:
Yes, you will also have to install Doors CS 7, which can be found in the archives.
This. Chat works via globalCALCnet (if your network is connected to gCn) to also connect to IRC, specifically #cemetech on Efnet.


Got that all downloaded. Now to scrounge a couple of ti-84's off Craigslist.

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