I’m helping out on a fun project to build an autonomous sailboat - http://www.sailbot.org. The desired design is to have an Arduino control servos and read sensors and communicate via either bluetooth or wifi to a droid phone onboard the boat. (Both Arduino sketches are done and working.) The absolute best way would be to use wifi to communicate with the droid - as this way we can program the autonomous sailing part using HTML/Javascript - nice outputs, easy to code and debug, etc. (Using XMLHTTPRequest for communication - works fine btw.)
The problem I’m having is that the ‘official’ Arduino wifi board, based on the sample wifiserver library for that board - is taking 1.3 seconds to respond to a simple http request. This is elapsed time on the Arduino from seeing a request to finishing. While it works, it would be much nicer to get, say 2x to 5x/second (sort of what we’d expect.) Also, flakiness on their board - but that hopefully will resolve itself over the next couple of months.
Ok, here’s the questions:
Will the wifly board be quicker? i.e., more than one http request/second?
Seems like the wifly board has a few challenges, per the discussion - and not much activity in the last 6 months. Is this board supported?
(Yes, bluetooth is the backup - trying to use a phonegap plugin, or worst case go to Amerindo)
definitely don’t use WiFi for this app. It’s a 20MHz channel-width medium. Power consumption, range, reliability are the issues.
For low data rate telemetry, use either bluetooth, or better, 802.15.4 as in Xbee and other plug and play modules.
Bluetooth’s problem is very low power, very short range. Not so some 802.15.4 modules, like XBee PRO which is 60mW and 1/10th the channel bandwidth of WiFi.
As stevech stated, for your application, bluetooth or RF modules would probably be a better choice. Xbees, once set up properly, work wonderfully. However though, to answer your questions, we have seen some delay issues with the official Wifi shield and are looking into this currently. However, it appears that it may be more on the code side of things, which we have no control over, unfortunately. I’d suggest simply keeping your ears open for any news that may come out of this.
In regards to the Wifly shield, there can be some difficulties getting started with it (we are working on getting a brand new library written for this that is compatible with the new Arduino 1.0 IDE), but we are still actively supporting the board. If you do have any questions about it, please let us know!
Wi-Fi works perfectly well for this type of application if the hardware and software are designed properly. We’ve used the UConTroll to control cars, boats, and quadrocopter using iPods, iPads and smartphones: http://www.UConTroll.com.