Sorry to post this message here, but I didn't find any general topic posting area.

Where are the POTM results? I shall be blind, because I've been looking for them during the last three days and I don't see anything.

- Roberto:.

Try Archives -> Past News and find the news item.

First, this is great! I'm going to work on an irc type program for the computer and calculator so people in an area can talk in chat rooms by using a single computer as a hub. It shouldn't take very long since I have help.

-KnightHero

Has this thing actually been tested though? Do you no if it truely works?

No, it has not, we are only in development stages, and released only pre-schematics as stated. Again, we will keep you updated with our progress. The schematics are only to provide you with a general idea for all the techies of what it is we are doing.

i'm interested to know how you are planning on implementing the interface between the calc and the micro you're using (btw, what micro are you using?? PIC? AMD?).

i have been working on a smililar interface project for awhile, and i am curious to how you accomplished this interface.

Nick, just sent you an email on that, thanks

We seem to be overlooking 3 major points:

1.) I believe that this is illegal in the US and omst other countries -- FCC regulations limit the distance one can transmit without a license

2.) You can only have 2 people using these within the given range. Add another pain of people trying to transmit data to each other and you're in trouble -- even worse with a 300 meter range

3.) I'll believe it when I see one WORKING at that distance -- not pre-release schematics

Information about the FCC regs for this device is found in:

TITLE 47--TELECOMMUNICATION
CHAPTER I--FEDERAL COMMUNICATIONS COMMISSION
PART 18--INDUSTRIAL, SCIENTIFIC, AND MEDICAL EQUIPMENT
Subpart A--General Information

Which states that this device may be used, without license, as long as transmitting distance does not exceed 300 meters (which is why the FM transceiver chip is limited to 300 meters) Therefore, this device is apparantly legal.

As for interception: Yes, I know, that is why we are still working on them. Developing a way to prevent signals from crossing.

Thanks

I think that this is a great idea. As for the crossing of signals, it's not that big a problem for a lot of us. How many people in a given school are going to use this thing? For most people who get this, it'll be them and someone they give it to (teacher, best friend, significant other). So while signal separation might be good (an IP system would be interesting), it's not necessary for most of us. Perhaps a cheaper pre-release version? Not trying to sound knowledgeable (I'm not with electronics), but just a consideration.

As I remember from my University course about network, there were protocoles called Aloha, Slotted Aloha, CSMA and CSMA/CD. CSMA/CD is best for situation when no repeaters are used (it is same protocol as in Ethernet, but using radio). For radio networks with repeaters, the best protocol is slotted Aloha.

In order to prevent collisions and signal crossing there are a few things that can be done. I believe ham packet radio uses a protocal called AX.25. What happens is all of the radios share the frequency by listening and only transmitting when the airwaves are quiet. Each packet has a header telling which person the packet is directed to. While everyone receives the same information, the only computer that displays the information is the one to whom the information is addressed. If you want to extend the distance without going over the 300 m transmitting limit, a digipeater could then be used.

Can different model calculators communicate with each other using the linc? If not, using different frequencies for the different model calculators could also cut down on traffic.

If it is same as plugging calculators together with a normal link, then nothing would be stopping two different models talking to each other. The only thing that real does work that I know of is Ztetris, which can be played 2 player between any calcs.

I am really not a hardware person, so if I am wrong, then somebody correct me. (I would like to know, if I am wrong about this)

Nick Chaves

Here's a suggestion: add an 8 way 'channel switch'.

For those who are interested, the datasheet of nRF0433 is available on Elfa's web page. Click on the "web page" link above.
On the page, click on the small 'i' in the order form. (between 'artikelnumm' and 'pris per st'). The page is in swedish but the datasheet is in english.

Their single unit price is around $14 (not including postage)

Anyway, the datasheet reveals the huge amount of work that Fission2 Lab must have done; Their schematics are about one-to-one copy of the included example schematic :-)

The chip itself is quite nice. Although limited to 9600bps half-duplex operation with 3ms switch-over time. Plus the frequency is shared with _all_ the users... Capable of handling small-scale email-services and non-realtime messaging.

I have to check the local legistlation before building one. I live near a large antenna array and if I cause interference with it they'll probably break my legs :-)

Yes, there are more componants to be added as these are only premilinary schematics. The schematics in the data sheet were not in a format that you could modify them, so I made them on Circuitmaker. If anyone would like my circuitmaker file, please send me an email...


The chips are $9.xx + Shipping from Richardson Electronics (keep in mind, this is just the IC, not the entire RadioLinc, you must build that)

As for interference, don't worry! No one uses that frequency, and no one owns the band 433mhz. I checked with FCC. Also, this is the Science band, used for experimental devices, (like this RadioLinc)

I have to get my hands on these things. I took a electronics class last year so i know the basics of electronics so if i can get a soldering iron and the parts i might be able to build one in around 5 trys. I was thinking that if someone near the school got there computer and hooked it up with a large antenne, mb several, And allowed to always be on and that if everyone was on own freq that connected to that computer you could have all connections thru the comp. This of course would allow that person to view the whole schools files... The only real way i could think to increase you range would be to put a antenne hooked up to a device that gets your signals and transmits at a much better or whatever makes it go farther in your locker... or in diff ppls lockers that r spread thru school for a gr8 network of connections.

Although if i get one.. i bet i will be only one---no one at my school even has sound sept me!!!!

Could you listen to the radio? you would need an electronic freq changer and a radio signall decoder and encoder to asm and a way to have both your speaker and the radiolic...right? i just gessing here. mb voice links? couldnt you attach a microphone to the com port and send voice? the problem here is--How to connect a RadioLinc, a Speaker, and a Microphone... but wouldnt that rock to have voice link??
Someday even VIDEO LINK? i meen couldnt you attach a low grade camera to a calc?
man this link could expand the calc to a whole new ballpark,
MB---WE could allow ppl to upload files to the server w/big antenne so you could have web pages!! i meen you simply add the files to calc and a auto delete when leave, in a TextView set up but with pics avalible to be put in and links inside it. and dl capabilty.

I am gonna shut up now.
CANT WAIT TO GET ONE OF THESE!!!

not to be rude, but your typing is hard to read :P

something about all the mb's, the captilization of wrong words, and other stuff...but that would rule to have all that stuff (although it doesn't seem to be set in the near future). Although your teacher would get suspicious hearing "you moron, you killed me in tetris" every few minutes :P

I know... i just wanted to say all that... I cant wait to somehow have this RadioLinc at school... i meen cheating(for those who do...not me..) would have no problem! And as for your teacher saying stop talking!! HAHAHAHA--and no more suspicios cables!!

hey--- its "batteries!" as far as we let her know
also--at fussion2 they say they gonna make it in clearish case-- i say make then in random colors and slightly diff shapes to throw them off.

great job! i have a great idea! im going to buy 2 2 way radios. i'll take out the part that sends and hook it up to my calc. that would be a two mile conection!

Hello,

Personally I would not try that. You need something that transmits and receives data, I'm not sure that your radio would. And if you mess up, there goes your radio, LOL

Is it possible to somehow extend the effective range of the unit? Whether through a larger antenna or different transmitter?

Also where and how much power does the Radio Link draw?

Hello,

The FCC limits it to 300 meters legally, but you can do whatever you want.