Wifi

Hello,
I'm lokking for a wifi (or other) solution to be used with microcontrollers,
and wich is able to transmit data (+ voice optionnaly) for distance up to
3km.
Thanks.

 

If you need 3 km range, government regulation will come into play, because
any signal that can be heard reliably at 3 km can cause some interference at
30 or even 300 km, and there is a finite range of frequencies available.

I suggest a cellular (mobile) telephone.

 

You might want a radio Modem.
http://www.radio-tech.co.uk/radio-modem.html

 

Interesting products. What is this "Hays" modem that they emulate? I know
all about "Hayes" modems with an e...

 

Hey,
Thanks for your reply.
I read some of datasheets, moste of disadvantages are :
1- Some of them uses chanels already in use by my embedded application.
2- The protocol used in not secured.
2- Modules are too big to put them inside my embedded application.
3- Small rate.
I need to explain more my aplication.
I'm working on PaintBall (electronic) application, something like CS game.
Each player is able to speak to a separate player in his team or to admin
via a voice server. Modules that i'm looking for will be able to
send/receive data/sound(voice) in an area of about 3Km² (minimal is 1Km²) in
a secure way, with a less of power consumption.
If anny one have a seggestion, dont hesitate to make it here.
Thanks for your help.

 

3 square km, or 3 km x 3 km? Not the same.

If you want a range of 3 km, radio regulation is definitely involved.

 

Sub-space radios have not been invented yet.

Time to come back to the real world.

Is a backpack or fanny-pack too big for this application ?

You might want to check out mesh networks.
This sounds like a good application for mesh.

Good luck

 

So you want suggestions which don't use channels you have not
specified. I don't think anyone who reads this group can read minds.

How big is too big?

Is there anything you don't want?

I suggest mobile (cellular) phones. GSM is hard to hack, cheap to buy
and does data and voice. Or do you want small, secure, powerful,
adaptable *and* cheap to run?


Tim

 

how about a uniden 40 channel CB radio. Each team just uses a separate
channel, and another for the "admin"

BTW in this real world paintball CS why do you need to spk with the "admin",
I mean, asking him to turn gravity off isn't going to do much. And he can't
take a screenshot of wallhackers because I don't think there will be too
many IRL

 

Hey,

lol, sorry, i haven't gave a good explanation about what i'm looking for.

Well i will give you a better idea about this work.

1- My first version :

The game contain weapons and waistcoats.
1-1 : Each weapon uses a laser module, a 433Mhz radio module to
communication with the waistcoat and few photodiodes (Players can shoot
opponent player's gun).
1-2 : waistcoat : this one use a bluetooth module to communicate with a
PC (PDA, Pocket PC ... ), a 433Mhz RF module, its also equiped with two
belt photodiodes (to read the laser information).

The system works fine, but only in dark rooms (only soft light), i need
to find better solutions to ensure the game working outside in daylight
conditions (* The project have no comercial purpose, it's only for fun
and it will be published for all PB lovers)

Annother problem is the use of two different modules & protocol (BT &
Simple RF comm), BT comm is limited two short ranges.

The last problem i have is that the BT is very greedy (I'm using TDK
blue2i modules), so i cant make more then 1 hour every game.

So, why dont i use a single module to ensure the communication of every
weapon with its waistcoat in one side, and each waistcoat with the PC
(PDA ...) in the other side.

The BT is used to initialize the game (Giving the player name, rank,
weapon kind ... ) and to get the score from each player.

Like i explained above, i need to make all that myself (I'm not an
electronic engineer i'm just a computer engineer) so if you have some
good experience using lazer modules, the uses of photodiodes in a
daylight conditions you will realy help me to make progress.

GSM is a good sollution, i dont know why i dont thaught about it, so i
want "small, secure, powerful (not important lol), adaptable *and*
cheap" modules to use them with 8, 16 microcontrollers.

Thanks.

 

You want filters on the "hit sensors" which match the frequency of the
lasers (but the narrower the passband of an optical filter the more it
costs...), if you don't have them already. You also want some kind of
modulation scheme. TV remotes should provide some inspiration for
modulation, encoding and compensating for background light levels -
that application has long since solved most of the problems associated
with using light to transmit data in variable conditions. Remember
that the laser "shots" can carry useful information (you got shot by x
with y weapon causing z damage), if you aren't using them that way
already.

By the sound of it the long-range comms is in irregular short bursts,
so GSM-based might well be feasible. GPRS would be better and cheaper
- you get charged by data not time, so you can keep the connection
open and send packets as required without your bill ticking over the
whole time. Either way, you should consider what data is time-critical
and how best to optimise your comm links (local RF, long range RF and
laser shots) for minimal power consumption and cost. For example, do
you need scores centrally within a second or will once a minute do?

I guess from playing commercial laser-tag (Quasar and Laser Quest in
the UK, no idea if they are more widespread or what other names they
may go under) that their kit primarily uses the laser shots to carry
hit information and this information is collected centrally when you
"recharge" (4 hits or out of ammo and you have to go to a "pod" to
recharge).


Tim

 

You want filters on the "hit sensors" which match the frequency of the

I thaught about taking the output from your transimpedance amplifier,
pass it through a low pass filter and take this signal via an
appropriate resistor to the summing junction of the transimpedance
stage, i need to make many tests. As i said above, i wont to make many
targets for the shooter on each waistcoat. In this case i have two
configurations :
1-Making a strip containing many Photodiodes in parallel (Hard to do,
need a relatively high reverse biase ...)
2-Making a separate targets (needs many I/O from the µC).
What do you think about the two solutions ?

Yes, i tested LaserQuest here in france, the principle is the same here.
Frankly, i dont enjoyed playing it. I hope to use the game outside, in
forests for exemple, so no more playing in a close rooms. I tried to do
that with some of my old schools friends and we found it realy cool
(sorry, i know that i'm out of the charter);
Well, I will look for (cheap, small ....) GSM/GPRS embedded modules,
dont hesitate if you have anny reference of GPRS modules application
note (used with microcontrollers ... google is not my friend these time).

Thanks to you and to all who tried to help me.

 

I thaught about taking the output from your transimpedance amplifier,

The best paper i found, talking about photodiodes concepts :
http://users.bestweb.net/~hobbs/frontends/frontends.pdf