Original Arduino WiFi Shield

The Arduino WiFi Shield allows you to connect your Arduino boards to wireless internet (802.11).

It is based on the HDG104 Wireless LAN 802.11b/g chip. The onboard Atmega 32UC3 handles TCP/IP and UDP stack operations. Thanks to the WiFi Library, you can write your own software in a simplified structure and easily connect your boards to wireless networks.

With its Arduino shield design, it works seamlessly with other shields, allowing you to connect your board to the internet while running other applications simultaneously.

The onboard micro SD card slot enables you to store files required for network operations directly on an SD card. The Arduino WiFi Shield is fully compatible with Arduino Uno, Mega, Due, and Leonardo. For SD card operations, you can use Arduino’s SD card library. The SS pin of the SD card is pin 4.

The Arduino communicates with the WiFi Shield processor and the SD card via the SPI bus. These pins are 11, 12, and 13 on the UNO, and 50, 51, and 52 on the MEGA. On both models, pin 10 is used as the select pin for the HDG104, and pin 4 for the SD card. These pins should not be used as general I/O pins. On the Arduino MEGA, the hardware SS pin (pin 53) is not used for the SD card or HDG104, but it must be set as an output.

Pin 7 on the Arduino is used for the handshake between the Arduino and the shield and should not be used for any other purpose.