WiFi - Arduino Sketches: Tools and Techniques for Programming Wizardry - page 177

This function takes no parameters and returns an int —the number of wire-
less networks detected. A scan can take a few seconds to complete, but when
done, the results are stored on the wireless chip, ready for interrogation. The
chip stores several pieces of information: the SSID name, the signal strength,
and the encryption type.
To retrieve the SSID of a network, use SSID() :

result = WiFi.SSID(num);

It takes one parameter: the number of a network scanned with the scanNet-
works() function. It returns a String : the name of the SSID.
To know the RSSI of a station broadcasting, use RSSI() specifying the net-
work number:

result = WiFi.RSSI(num);

Exactly like RSSI() used to learn the RSSI of the current network, this function
returns a long , the value in dBm, short for Decibel-milliwatts. Typical values
range from −80 to 0; the higher the number, the better the reception.
Wireless networks also broadcast their security, specii cally the encryption
method required to connect (if any). To know the encryption of a network, use
encryptionType() , specifying the network number:

result = WiFi.encryptionType(num);

This function returns a constant: the type of encryption detected. Table 10-2
lists the values.

Table 10-2: Possible Encryption Types

VALUE MEANING

ENC_TYPE_WEP WEP encryption

ENC_TYPE_TKIP WPA encryption

ENC_TYPE_CCMP WPA2 encryption

ENC_TYPE_NONE

No encryption, open network

ENC_TYPE_AUTO Multiple encryption methods possible

Connecting and Confi guring
To connect to a wireless network, use begin() , explained previously in the
“Initialization” section. To disconnect from a network, use disconnect() :

WiFi.disconnect();