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[on:]

Hi,

I'm working on my PFC (Final Year Project in spain) and wanted to connect an Arduino with a transceiver. The data sent/received will be very small (no more than 50bytes) and the communication won't be constant, I mean, I will send/receive information every X seconds (X>1).

I'm not very into this transceivers thing, and first I thought of WiFi, because at reception I just need a router which I can connect with a computer acting as a server (since the data has to interact with a DB). But I saw that this modules are pretty expensive, and I (might) need more than one. That is another point why I thought WiFi would be a nice solution, the protocol itself takes care of everything if I want to connect more than one device to a single router.

Then I found ZigBee, which is slightly cheaper than WiFi and (I think) fullfils my requirements, but I have never used ZigBee so I don't know...

Of course since the data packets are really small I know there might be even better solutions for my problem, last year I worked on a project where we used TI transceiver CC112 @ 169MHz the problem is that this project was point to point and just in one direction (simplex). And now I'm looking for multipoint to point and both directions (like WiFi).

Knowing all this, who can tell me something about the transceiver I should use? WiFi, ZigBee or another?

Thanks a lot (and sorry for my english),
Carlos

[Reply #1 on:]

Hi Carlos,
Your English is fine. No se preocupe. (My Google Spanish...)

If cost is a factor, maybe look on the http://ArduinoInfo.Info WIKI and
http://arduino-info.wikispaces.com/Nrf24L01-2.4GHz-HowTo

There is a multidrop network project here: http://maniacbug.github.com/RF24Network/index.html

Some example hardware here: http://goo.gl/Bn9fw  (Widely available elsewhere too)

DISCLAIMER: Mentioned stuff from my own shop...

[Reply #2 on:]

I have a bunch of XBees and an Arduino WiFi shield. I can't keep the Wifi shield serving data for more than a few seconds at a time. A couple of minutes at most. Then, it needs to be powered off, left disconnected for a few minutes, and then reconnected to work again for a couple of minutes.

The XBees, on the other hand, will send data back and forth for hours at a time. They cost, with shields or breakout boards, slightly more, but they work.

[Reply #3 on:]

(and sorry for my english)

Every time I see this, its almost guaranteed that the poster writes better than 90% of my US customers.

I use these RN-XV wifi modules:
https://www.sparkfun.com/products/10822

$35, neat set of features, fits into an Xbee socket. I guess it would depend on the application. Xbee's are nice if you need to make your own network, WiFi is nice if the network is already there. There's also a lot of cheap consumer WiFi products that you can connect to with a WiFi module.

EDIT: Re-reading your post, this seems almost exactly the same setup that I have. I have a Raspberry Pi running Apache, PHP, and MySQL, and a bunch of sensors connected to RN-XV modules that periodically send data to the RPi Server.