Arduino WiFi Shield

By on January 30, 2012
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The shield most used in practice are those that expand the communication of the Arduino board and in particular those that allow to add a network connection to a TCP / IP.
The first shield of this kind were those based on Ethernet technology, which helps the Arduino to connect to a LAN based on Ethernet TCP / IP, and so to Internet.
The convenience of Wi-Fi is now known to all: no more cables to spread (which increases the cost and time of construction of any plant) and full freedom in the positioning of the different nodes of the wireless network.

One of the first companies to focus on Wi-Fi was the AsyncLabs, who proposed a famous WiFi shield, including the appropriate libraries.
What we propose is a new solution for Wi-Fi: this is a shield that the hardware was inspired by that of AsyncLabs, but in addition, we have provided a slot for microSD memory.

The basic component of the shield that we have made is a Wi-Fi module MRF24WB0MA manufactured by Microchip.
The device is a Wi-Fi IEEE 802.11 RF transceiver, with a data rate between 1 and 2 Mbps, and with an internal antenna.
The WiFi shield supports both types of wireless networks infrastructure (BSS) and ad-hoc (IBSS) and is also allowed to connect to secure networks (cryptographers and are supported 64 and 128-bit WEP, WPA/WPA2 and TKIP, AES and PSK).

In our project is using the SPI connection for communication with the WiFi controller through the SDO, SCK and SDI (pin 32, 34 and 35) and, if necessary, can be reset using a button (P1 in the diagram).
Peculiarities of our shield is that it has a SD card slot (SD1 signed in the schematic), managed by Arduino always through the SPI port.
There is also a LED (LD1 signed) used to indicate whether the Wi-Fi is active or not, its management is implemented through a hardware port, so you usually can not be used by software. In the event that was needed precisely this port, you still have a jumper that, when opened, making it available again disconnect the LED pin I / O.
Finally, to complete the hardware of the shield there is a section dedicated to the power, consists of a 3.3 V voltage regulator (indicated with U2).



R1: 4,7 kohm (0805)
R2: 4,7 kohm (0805)
R3: 4,7 kohm (0805)
R4: 4,7 kohm (0805)
R5: 1 kohm (0805)
R6: 4,7 kohm (0805)
R7: 2,2 kohm (0805)
R8: 1 kohm (0805)
R9: 2,2 kohm (0805)
R10: 1 kohm (0805)
R11: 2,2 kohm (0805)
R12: 330 ohm (0805)

C1: 220 µF 6,3 VL (D)
C2: 220 µF 6,3 VL (D)
C3: 100 nF (0805)
C4: 100 nF (0805)
C5: 100 nF (0805)

LD1: Led (0805)

U2: TC1262-3.3 (SOT-223)


P1: switch SMD

– headers  male 2 via
– headers  M/F 6 via(2 pz.)
– headers  M/F 8 via(2 pz.)
– headers  M/F 3 via(2 pz.)
– Jumper


The library supports various operating modes, which are Web Server, Web Client, Socket, UDP and WiServer.

The library is constantly evolving, so we have provided a space where they will be published on various versions available.

Code Example for WiFi shield

 Web Client

Web Server





About Boris Landoni

Boris Landoni is the technical manager of Skilled in the GSM field, embraces the Open Source philosophy and its projects are available to the community.

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18 Comments on "Arduino WiFi Shield"

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[…] The library is constantly evolving, so we have provided a space where they will be published on various versions available. […]

Gab Fusco

I have uploaded the “server” sketch on my arduino uno but how can i check and connect to them ? thanks

Gab Fusco

I think the wi-fi shield is not powered. The green led is off. How can i check? my power supply output: 12v 2.0A



The codes should be program in which programming language/software?


nell’esempio WebServer le due funzioni Led_Rosso_ON() e Led_Rosso_OFF() temo siano invertite!


is possible to buy or get free the PCB of the micrichip wifi module board


i have 2 questions:

1) in AsyncLabs wifi shield the INTX pin of the wifi module (pin 33) is connected to Arduino DIG2 or DIG8 pins (jumper switch).
In your wifi shield it isn’t.

2) can I use Arduino Serial Monitor while your wifi shield runs? there are conflicts?




I have problems with the module.
I am using an arduino mega with ide 1.0 and the version of the library to Tidigino.
I got connect to the router (I see associated with its Mac, and the green LED turns on), but does nothing more (as well as server and client does not advance the “WiServer.init (NULL).”
I tried to follow the library, but I get lost in it.
Where can be the problem?


the led light on the wifi shield is on, but i cannot open the browser from the PC, is there anything that i have done wrong?


Probably you have to set other parameters, like IP address… and of course check the sketch…


[…] Despite the proliferation of hardware to connect Arduino with the web, and especially despite YUN, we considered useful to design and propose a new WiFi shield for Arduino, which replaces the one already presented. […]


Could you tell me how to set it as a socket client? Thanks!


Hi this a old version of the wifi shield.
Check this one


[…] Arduino WiFi Shield | Open Electronics – WiFi shield for Arduino. The basic component of the shield that we have made is a Wi-Fi module MRF24WB0MA manufactured by Microchip. […]