WiFly Shield

**Replacement: **WRL-09954. The new version breaks out the PI09, FORCE WAKE, and the hardware reset lines. It also has a different crystal and uses the RN-131C. This page is for reference only.

The WiFly Shield equips your Arduino the ability to connect to 802.11b/g wireless networks. The featured components of the shield are a Roving Network's RN-131G wireless module and an SC16IS750 SPI-to-UART chip. The SPI-to-UART bridge is used to allow for faster transmission speed and to free up the Arduino's UART.

Power is taken from the Vin pin of your Arduino, regulated to 3.3V, and provided to both the RN-131G and the SC16IS750. You'll communicate with the WiFly Shield over SPI using Arduino digital pins 10-13 (CS, MOSI, MISO, SCLK respectively).

The shield includes the RN-131G, SC16IS750 and their supporting components. The shield also provides a small prototyping area, with 0.1" spaced holes. Headers are not soldered on, we recommend the 6 and 8-pin stackable headers.


Looking for answers to technical questions?

We welcome your comments and suggestions below. However, if you are looking for solutions to technical questions please see our Technical Assistance page.

  • sparkfunk / about 14 years ago / 2

    I finally got this board to work with Arduino Mega. I'm sorry to say it takes some modifications to make it work. Basically you have to change the pins in Spi.h to match the mega and do the hack described at <http://mcukits.com/2009/04/06/arduino-ethernet-shield-mega-hack/>. Good Luck!

  • RAM / about 14 years ago / 2

    Where can i find an arduino sketch to kick start the development when i but them !

  • Davemaster / about 12 years ago / 1

    Any WiFly Shield equivalent for arduino or maple¿

  • briGHT / about 14 years ago / 1

    quick question: once I connect the Wifly to the Arduino, should I get any led to turn on?
    I'm wondering this because I try to connect using the code avaliable in the tutorial, and I get the message:
    "Could not initialize bridge, locking up."
    I have no idea what to do?
    Any help?

  • Racine / about 14 years ago / 1

    Salut tout le monde !
    Anyone have tryed UDP mode ? Who have sample ?
    I have succeed to setup auto pairing mode tought broadcast, but i have don't find the way for send data in UDP mode .... :(
    Thx all

  • ovidiup / about 14 years ago / 1

    After buying the board, I was disappointed to discover the RN-131G only supports one active TCP connection at any given time, unlike the Ethernet shield which supports up to 4 connections. This means the shield cannot be used to implement an Ajax-type web server, since most such web apps would need 2 connections opened to the server.

  • bigal / about 14 years ago / 1

    Can someone help? After I type $$$, I get this (the last line repeats over and over):
    WiFly Shield Terminal Routine
    Bridge initialized successfully!
    Auto-Assoc roving1 chan=1 mode=NONE FAILED
    Auto-Assoc roving1 chan=1 mode=NONE FAILED
    Whatever I type after is only echoed back to the PC.
    Any ideas?

  • dfa327 / about 14 years ago / 1

    Very important if you are just buying one of these now and are using the examples above to test it out. The new wifly operates at a faster frequency of 14745600UL. So you need to adjust the line that is:
    struct SPI_UART_cfg SPI_Uart_config = {
    struct SPI_UART_cfg SPI_Uart_config = {
    See here for more info:

  • breezetrees / about 14 years ago / 1

    What voltage regulator are you using? It's not clear from the schematic. Mine powers off at about 15V (when I'm charging my 12V battery). I'm considering moving the power to the regulator from Vin to the 5V line.

  • breezetrees / about 14 years ago / 1

    I bought one of these to send twitter updates for a sensor project I'm working on. If anyone wants to they can check out my code (based on the sparkfun tutorial):

  • ProjTX / about 14 years ago / 1

    I'm having the same problem. I can get it to work fine in command mode over USB, issue commands perfectly. But not connect to either of my networks. Channels, baud, MHz all seem to match. But I can't get it to associate with a network. On one network security is 3, on the other it is 0 (open) and still nothing.
    Please help!

  • THERAMstat / about 14 years ago / 1

    Hey there:
    I am working with this Wifi module.
    I got this to work with my arduino and I am able to access the command lines via USB comport.
    But I want to send data to my computer that is being generated by my arduino wireless. I know how to do it wired(USB), but not wireless.
    can some one help with this?

  • MLumi / about 14 years ago / 1

    Will I be able to connect to WiFly from Arduino via UART with 250000 baud rate?
    Or it will still require SPI?

  • z3roadster19 / about 14 years ago / 1

    I was using the the sketch and information posted by 'El Hombre Mecatr?nico' and I was able to get my project running but it wouldn't remain stable. At times the SPI bridge would be unworkable for days (multiple resets).
    I modified my program to use SparkFun's code in this tutorial and everything works perfectly. No hang-ups. No unresponse SPI bridge issues.
    This is definitly the solution for everyone. I really appreciate the fact that they took the time to put this together. Just wish something like this existed two months ago when I first purchased the board.

  • Biotech / about 14 years ago / 1

    I didn't think the Arduino library supported SPI?

  • HombreMecatronico / about 14 years ago / 1

    You can find an arduino sketch (WiflyTerm 1.0) that gives you access to the RN-131G through the arduino's serial port.
    Just open a Hyperterminal (not the arduino serial monitor) and configure the USB serial port at 9600,N,8,1 with no flow control, and type $$$ to enter the configuration console.
    You can configure unconnected wifly modules and save the configuration in NV memory as the default, so the module connects automatically and this program is no longer needed. With this program you don't need to change your network SSID/encription to configure the module.
    The blog entry in spanish (sorry): http://hombremecatronico.es/?p=247
    Or just get the Wiflyterm 1.0 at: http://hombremecatronico.es/wordpress/wp-content/uploads/2010/01/wiflyterm.zip
    Sincerely: El Hombre Mecatr?nico

  • vanadium / about 14 years ago / 1

    I'm running the above code and getting absolutely no response using the code linked to above. Anyone?

    • vanadium / about 14 years ago / 1

      I retract the above; was able to get 'er configured over the ad-hoc network 'roving1' through the telnet interface provided in the reference. Now, to make sweet use of this fine unit...

  • GlennH / about 14 years ago / 1

    Why is the SC16IS750 interrupt connected to Digital 7, instead of D2 or D3, which are the CPU external interrupt pins?

  • TimDaMan / about 14 years ago / 1

    Check out http://hombremecatronico.es/?p=247 its in Spanglish, but has the code to get started.

  • dburrows / about 14 years ago / 1

    We can't get this to work with the Arduino Duemilanove. More specifically we don't receive any response from the SPI chip. Is there any starter code?

  • s.mihai / about 14 years ago / 1

    any idea when this product will be back in stock ?

  • Surge311 / about 14 years ago / 1

    I'm surprised that nobody has mentioned the WiShield yet. It's an equivalent shield for $35.00 less. It also has a pretty decent following in the Arduino forums.
    Check it out! http://asynclabs.com/store?page=shop.product_details&flypage=flypage.tpl&product_id=17&category_id=6

    • Surge311 / about 14 years ago / 1

      Well, apparently I didn't read the comments well enough, because It was already mentioned.

  • rickburgen / about 14 years ago / 1

    Can this be used with the Arduino Mega?

  • invincible707 / about 14 years ago / 1

    Can anyone help me understand why Arduino can't be connected to RN-131G module directly using SPI interface instead of going through a SPI-UART bridge like one on this board ?

  • jbookout / about 14 years ago / 1

    would love to see a tutorial on wifi bootloading the arduino...you're right there on the isp pins for the avr....

  • skystorm / about 14 years ago / 1

    Why you use RN-131G??? RN-131! the similar but chipper.

Customer Reviews

No reviews yet.