Arduino WiFi Shield Arduino WiFi Shield Front Arduino WiFi Shield Back Download: arduino-wifi-shield-schematic.pdf , arduino-wifi-shield-reference-design.zip WiFi Shield Library WiFi shield firmware and library at github Overview The Arduino WiFi Shield connects your Arduino to the internet wirelessly. Connect it to your wireless network by following a few simple instructions to start controlling your world through the internet. As always with Arduino, every element of the platform – hardware, software and documentation – is freely available and open-source. This means you can learn exactly how it's made and use its design as the starting point for your own circuits. Requires and Arduino board (not included) Operating voltage 5V (supplied from the Arduino Board) Connection via: 802.11b/g networks Encryption types: WEP and WPA2 Persoanl Connection with Arduino on SPI port on-board micro SD slot ICSP headers FTDI connection for serial debugging of WiFi shield Mini-USB for updating WiFi shield firmware Description The Arduino WiFi Shield allows an Arduino board to connect to the internet using the 802.11 wireless specification (WiFi). It is based on the HDG104 Wireless LAN 802.11b/g System in-Package. An Atmega 32UC3 provides a network (IP) stack capable of both TCP and UDP. Use the WiFI library to write sketches which connect to the internet using the shield. The WiFI shield connects to an Arduino board using long wire-wrap headers which extend through the shield. This keeps the pin layout intact and allows another shield to be stacked on top. The WiFi Shield can connect to wireless networks which operate according to the 802.11b and 802.11g specifications. There is an onboard micro-SD card slot, which can be used to store files for serving over the network. It is compatible with the Arduino Uno and Mega. The onboard microSD card reader is accessible through the SD Library. When working with this library, SS is on Pin 4. Arduino communicates with both the Wifi shield's processor and SD card using the SPI bus (through the ICSP header). This is on digital pins 11, 12, and 13 on the Uno and pins 50, 51, and 52 on the Mega. On both boards, pin 10 is used to select the HDG104 and pin 4 for the SD card. These pins cannot be used for general I/O. On the Mega, the hardware SS pin, 53, is not used to select either the HDG104 or the SD card, but it must be kept as an output or the SPI interface won't work. Digital pin 7 is used as a handshake pin between the WiFi shield and the Arduino, and should not be used. Note that because the HDG104 and SD card share the SPI bus, only one can be active at a time. If you are using both peripherals in your program, this should be taken care of by the corresponding libraries. If you're not using one of the peripherals in your program, however, you'll need to explicitly deselect it. To do this with the SD card, set pin 4 as an output and write a high to it. For the HDG104, set digital pin 10 as a high output. The shield can connect to encrypted networks that use either WPA2 Personal or WEP encryption. It can also connect to open networks. A network must broadcast its SSID for the shield to be able to connect. The reset button on the shield resets both the HDG104 and the Arduino board. There is an onboard Mini-USB connector. This is not for programming an attached Arduino, it is for updating the Atmega 32U using the Atmel DFU protocol. The programming jumper adjacent to the power bus and analog inputs should be left unconnected for typical use. It is only used for DFU programming mode. An onboard FTDI connection enables serial communication with the 32U for debugging purposes. A list of available commands can be found here. The shield contains a number of informational LEDs: L9 (yellow) : this is tied to digital pin 9 LINK (green) : indicates a connection to a network ERROR (red) : indicates when there is a communication error DATA (blue) : indicates data being transmitted/received See also: getting started with the WiFi shield and WiFi library reference Arduino WiFI Shield The Arduino WiFi shield allows an Arduino board to connect to the internet using the WiFi library and to read and write an SD card using the SD library. The WiFi Library will be included in a future release of the Arduino IDE. You can download the most recent version, and install it as you would any other library. The WiFI library is similar to the Ethernet library and many of the function calls are the same. On this page... (hide) Connecting the Shield Using the Shield With Older Boards Ports on the WiFi Shield Network Settings Scan for available networks Open network example WPA network example WEP Network example SD Card and SPI Connecting the Shield To use the shield, mount it on top of an Arduino board (e.g. the Uno). To upload sketches to the board, connect it to your computer with a USB cable as you normally would. Once the sketch has been uploaded, you can disconnect the board from your computer and power it with an external power supply. Digital pin 7 is used as a handshake pin between the WiFi shield and the Arduino, and should not be used. Using the Shield With Older Boards If you are using the WiFi shield with an Arduino earlier than the Uno rev3, you need to make the connection below for the board to work. The WiFi board uses the IOREF pin on newer Arduino pins (Uno rev3, Mega2560 rev3, and later) to sense the reference voltage for the I/O pins of the board to which it is attached. If you are using the shield with an older board, you need to connect the shield's IOREF pin to 3.3V. You can do this either with a jumper wire connecting IOREF to 3.3V as shown in the photo below, or by soldering the IOREF jumper on the bottom of the shield, shown below. WARNING: If you use the solder jumper, do not connect the shield to a rev3 or later board. To be safe, remove the IOREF pin on the shield. Otherwise, you will be shorting 3.3V to 5V through the IOREF pin. Jumping 3.3V to IOREF (recommended) Soldering 3.3V to IOREF Ports on the WiFi Shield There is an onboard micro-USB connector. This is not for programming an attached Arduino, it is for updating the Atmega 32UC3 using the Atmel DFU protocol. The programming jumper adjacent to the power bus and analog inputs should be left unconnected for typical use. It is only used for DFU programming mode. A FTDI connection enables serial communication with the 32UC3 for debugging purposes. A list of available commands can be found here. Network Settings The shield will connect to open networks, as well as those using WEP and WPA2 Personal encryption. The shield will not connect to networks using WPA2 Enterprise encryption. The SSID (network name) must be broadcast for the shield to connect. Depending on your wireless router configuration, you need different information. For an open (unencrypted) network, you need the SSID. For networks using WPA/WPA2 Personal encryption, you need the SSID and password. WEP network passwords are hexadecimal strings known as keys. A WEP network can have 4 different keys; each key is assigned a "Key Index" value. For WEP encrypted networks, you need the SSID, the key, and key number. Scan for available networks The sketch below is a good one to run the first time you use the board in a new area. This sketch will not connect to a network, but it will show you what networks the shield can view. Your WiFi shield will probably not see as many networks as a computer with a larger WiFi antenna. Once you have downloaded the sketch to your Arduino, open the serial port to see available networks. #include #include void setup() { // initialize serial and wait for the port to open: Serial.begin(9600); while(!Serial) ; // attempt to connect using WEP encryption: Serial.println("Initializing Wifi..."); printMacAddress(); // scan for existing networks: Serial.println("Scanning available networks..."); listNetworks(); } void loop() { delay(10000); // scan for existing networks: Serial.println("Scanning available networks..."); listNetworks(); } void printMacAddress() { // the MAC address of your Wifi shield byte mac[6]; // print your MAC address: WiFi.macAddress(mac); Serial.print("MAC: "); Serial.print(mac[5],HEX); Serial.print(":"); Serial.print(mac[4],HEX); Serial.print(":"); Serial.print(mac[3],HEX); Serial.print(":"); Serial.print(mac[2],HEX); Serial.print(":"); Serial.print(mac[1],HEX); Serial.print(":"); Serial.println(mac[0],HEX); } void listNetworks() { // scan for nearby networks: Serial.println("** Scan Networks **"); byte numSsid = WiFi.scanNetworks(); // print the list of networks seen: Serial.print("number of available networks:"); Serial.println(numSsid); // print the network number and name for each network found: for (int thisNet = 0; thisNet char ssid[] = "yourNetwork"; // the name of your network int status = WL_IDLE_STATUS; // the Wifi radio's status void setup() { // initialize serial: Serial.begin(9600); // attempt to connect to an open network: Serial.println("Attempting to connect to open network..."); status = WiFi.begin(ssid); // if you're not connected, stop here: if ( status != WL_CONNECTED) { Serial.println("Couldn't get a wifi connection"); while(true); } // if you are connected : else { Serial.print("Connected to the network"); } } void loop() { // do nothing } [Get Code] WPA network example The example below shows how to connect to a WPA/WPA2 Personal encrypted network named "yourNetwork" with a password "12345678". #include char ssid[] = "yourNetwork"; // your network SSID (name) char pass[] = "12345678"; // your network password int status = WL_IDLE_STATUS; // the Wifi radio's status void setup() { // initialize serial: Serial.begin(9600); // attempt to connect using WPA2 encryption: Serial.println("Attempting to connect to WPA network..."); status = WiFi.begin(ssid, pass); // if you're not connected, stop here: if ( status != WL_CONNECTED) { Serial.println("Couldn't get a wifi connection"); while(true); } // if you are connected, print out info about the connection: else { Serial.println("Connected to network"); } } void loop() { // do nothing } [Get Code] WEP Network example Your router will most likely have a settings dialog similar to the one below for generating the WEP key based on an ASCII passphrase: If you do not have access to your router's administrative tools, consult your network administrator. Each key is 10 or 26 hexadecimal digits long (40 or 128 bits) and paired with a key number. For example, a 40-bit key, ABBADEAF01 will work, but ABBADEAF won't work (too short) and ABBAISDEAF won't work (I and S are not hexadecimal characters).vFor 128-bit, you need a string that is 26 characters long. D0D0DEADF00DABBADEAFBEADED will work because it's 26 characters, all in the 0-9, A-F range. NB : WEP provides a basic encryption mechanism, but it can be cracked. If you require strong encryption for your network, it is recommended you use WPA The example below shows how to connect to a WEP encrypted network named "yourNetwork" with a hex key of "ABBADEAF01", and a key index of 0. #include char ssid[] = "yourNetwork"; // your network SSID (name) char key[] = "ABBADEAF01"; // your network key int keyIndex = 0; //your network key Index number int status = WL_IDLE_STATUS; // the Wifi radio's status void setup() { // initialize serial: Serial.begin(9600); // attempt to connect using WEP encryption: Serial.println("Attempting to connect to WEP network..."); status = WiFi.begin(ssid, keyIndex, key); // if you're not connected, stop here: if ( status != WL_CONNECTED) { Serial.println("Couldn't get a wifi connection"); while(true); } // if you are connected, print out info about the connection: else { Serial.println("Connected to network"); } } void loop() { // do nothing } [Get Code] SD Card and SPI The WiFI Shield includes a micro-SD card slot, which can be interfaced with using the SD library. The SS for the SD card is pin 4. Arduino communicates with the shield using the SPI bus. This is on digital pins 11, 12, and 13 on the Uno and pins 50, 51, and 52 on the Mega. On both boards, pin 10 is used as SS. On the Mega, the hardware SS pin, 53, is not used, but it must be kept as an output or the SPI interface won't work. The text of the Arduino getting started guide is licensed under a Creative Commons Attribution-ShareAlike 3.0 License. Code samples in the guide are released into the public domain. | Share ©Arduino | Edit Page | Page History | Printable View | All Recent Site Changes http://arduino.cc/en/Guide/ArduinoWiFiShield[9/19/2012 2:03:10 PM]