Ethernet

Digital I/O
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Ethernet
Ethernet (Server)
Ethernet (Client)
Servo Motor
Character LCD
SPI
I²C (Wire)
SD Card
SD (File Operations)
Periodic Operation
Clock (RTC)

This is a library for Ethernet initialization. Specify #include <Ethernet.h> for use.

begin

Description

Initializes the Ethernet library and network settings. The DHCP automatically obtains an IP address, DNS, default gateway, and subnet mask.

Syntax

int Ethernet.begin(mac)
Ethernet.begin(mac, ip)
Ethernet.begin(mac, ip, dns)
Ethernet.begin(mac, ip, dns, gateway)
Ethernet.begin(mac, ip, dns, gateway, subnet)

Parameters

mac: MAC address (array of 6 bytes)
ip: IP address (array of 4 bytes)
dns: Name server address (array of 4 bytes)
gateway: Default gateway address (array of 4 bytes)
subnet: Subnet mask (array of 4 bytes)

Returns

If Ethernet.begin(mac) is successful = 1; if failure = 0. Others are none.

localIP

Description

Obtains the IP address of the board.

Syntax

IPAddress Ethernet.localIP()

Parameters

None

Returns

The IP address

Connect with DHCP, and then display the IP address.

#include <Arduino.h>
#include <Ethernet.h>
 
byte mac[] = {  
  0x00, 0xAA, 0xBB, 0xCC, 0xDE, 0x02 };
// Initialize the Ethernet client library
// with the IP address and port of the server 
// that you want to connect to (port 80 is default for HTTP):
EthernetClient client;
  
void setup()
{
    Serial.begin(9600);
    Serial.println("Start to connect..");
 
    // start the Ethernet connection:
    if (Ethernet.begin(mac) == 0) {
        Serial.println("Failed to configure Ethernet using DHCP");
        while(1);
    }
    // print your local IP address:
    Serial.println(Ethernet.localIP());
}
  
void loop() {
}