Xbee/Wireless

Hi. I recently started Arduino(a few months). I am starting to explore wireless capabilities. I want a robust data link that is relativley easy to use, but not too expensive. It must also be compatible with an arduino uno. I was thinking Xbee, but I wanted some advice on what to do/buy.

Here is an XBee introduction and buying guide: http://www.sparkfun.com/tutorials/257

Here is a Bluetooth guide: http://www.sparkfun.com/tutorials/67

Ok, so I think ive decided on an Xbee. However I do have a few questions about them.

  • - What is their typical range(not MAX. but average) inside and outside?(Series one)
  • - Can I plug 2 series 1s into two arduino unos(with shields) and have an immediate serial connection?
  • - How consistant are they? How sure can I be that the data I send WILL be recieved?
  • - What factors affect range and by how much?
  • - I have also read in comments that there are problems with the Xbee Shield... The comments are old so I wondered if it has been fixed.
  • If I do purchase them I plan on getting two Series 1s, should they be wire antenna, chip antenna, or U.FL, and what difference does it make?(Other than how it looks)

    Range is determined by the amplitude and frequency of the radio: Higher amplitude gives the data more drive power (if you will), it allows it to reach further. Lower frequency usually means longer distance due to the ease of penetration.

    See this data sheet for most of the information you asked for: http://www.sparkfun.com/datasheets/Wire … asheet.pdf

    I don’t want to reiterate what it says.

    I am sorry I can’t really show you “how I did it” because I have not done anything with XBee… yet.

    N314:
    If I do purchase them I plan on getting two Series 1s, should they be wire antenna, chip antenna, or U.FL, and what difference does it make?(Other than how it looks)

    Chip Antenna – Basically a small chip that acts as an antenna. Quick, easy, cheap, not in the way.

    Wire Antenna – Well its a small wire sticking up, a little more of what you think of when you think of antenna.

    u.FL Antenna – A tiny connector to connect your own antenna, this is great if your object is in a box and you want your antenna outside the box.

    I used 2 series1 in a project for the house.

    Once set to the same settings they talk to each other ok.

    There is a ‘connect’ time thats several seconds, so if your system goes to sleep, the wake time is several seconds.

    The low power units work within my 2 story, 2800sqft house with no issues (chip antennae).

    For simple point to point comms, xbees only satisfy your ‘easy to use’ bullet, they are expensive.

    I got some RF12 (now they have Rf22) in 900Mhz for $5 each. But it takes more sw in the arduino to run them.

    njr27:
    Chip Antenna – Basically a small chip that acts as an antenna. Quick, easy, cheap, not in the way.

    Wire Antenna – Well its a small wire sticking up, a little more of what you think of when you think of antenna.

    u.FL Antenna – A tiny connector to connect your own antenna, this is great if your object is in a box and you want your antenna outside the box.

    Do these (And if so by how much) different Antennae affect range?

    I am not sure. I assume that the antennae does help but it is mainly for getting the radio outside of the box of the enclosure.

    Xbee series 1 is about 2mWatt xmit and Series 1 Pro is about 60mW. Assuming the 2.4GHz products, not 900MHz.

    That affects range a great deal.

    As does choice of antenna. The on-PCB chip antenna is the poorest. The short-wire is better. The U.FL connector and a good antenna on at least one end is best.

    I was planning on the chip antenna. Im ok if its range is a bit less than the others, but is at a drastic difference?

    yes, a significant difference between a chip antenna and a short-wire. And a U.FL antenna connector leading to a “real” antenna is the huge difference.

    Using the more expensive higher power XBee Series 1 Pro (~60mW) is equivalent to improving the antenna (gain) by about 14dB. Conversely, if the XBee non-PRO (2mW) had a 14dBi gain antenna, it would be equivalent to the Pro, in range, if the radio to which it is communicating had a similar matching radiated power.

    What range is your goal, and what obstructions are in the paths you expect?

    Obstructions: Normal house walls.

    Range: 50-100ft inside, 150-200ft outside… is this do-able with a chip antenna?

    Those ranges will not be reliable with the chip antenna.

    The whip antenna will get you there though.

    :slight_smile: I’ve done lots of playing with the xbee series 1.

    Whip on Xbee pro is awesome

    Sorry, Ive never heard of a “whip” antenna, what is that?

    Ive also read some comments about the Xbee sheild for Arduino that say it does not work well. Are these problems that are “not fixable” or just add a solder jumper?

    N314:
    Sorry, Ive never heard of a “whip” antenna, what is that?

    http://lmgtfy.com/?q=xbee+whip

    Well now you have.

    Looks like for long range WiFi is preferred over Zigbee.

    Below are some quick difference;

    ZigBee:

    Data Rate:- 20, 40, and 250 Kbits/s

    Range:- 10-100 meters

    Networking Topology:- Ad-hoc, peer to peer, star, or mesh

    Operating Frequency:- 868 MHz (Europe),900-928 MHz (NA)

    Complexity(Device and application impact):- Low

    Power Consumption:- Very low (low power is a design goal)

    Typical Applications:- Industrial control and monitoring, sensor networks, building automation, home control and automation, toys, games

    WiFi:

    Data Rate:- 11 & 54 Mbits/sec

    Range:- 50-100 meters

    Networking Topology:- Point to hub

    Operating Frequency:- 2.4 and 5 GHz, 2.4 GHz (worldwide)

    Complexity(Device and application impact):- High

    Power Consumption:- High

    Typical Applications:- Wireless LAN connectivity, broadband Internet access

    N314:
    Ive also read some comments about the Xbee sheild for Arduino that say it does not work well. Are these problems that are “not fixable” or just add a solder jumper?

    There's one SFE board, I don't recall which, that has a diode in series with the data line. This is an incorrect (lame) attempt to level shift 5V to 3.3V.

    Also be aware that Digi is replacing the chip antenna with a better fractal PCB trace antenna. You can check the XBee OEM Module documentation for more info.

    For example: http://www.digi.com/support/productdeta … umentation

    PCB chip antenna is the poorest. The short wire is better. U.FL connector, and a good antenna at least [HP 97 one end is the best.](Best Ink Cartridges - MeritLine)