Ethernet : UDP.read()
Reads UDP data from the specified buffer. If no arguments are given, it will return the next character in the buffer.
This function can only be successfully called after UDP.parsePacket().
UDP.read();
UDP.read(packetBuffer, MaxSize);
packetBuffer: buffer to hold incoming packets (char)
MaxSize
: maximum size of the buffer (int)
char : returns the characters in the buffer
#include <SPI.h>
#include <Ethernet.h>
#include <EthernetUdp.h>
// Enter a MAC address and IP address for your controller below.
// The IP address will be dependent on your local network:
byte mac[
]
=
{
0xDE
,
0xAD
,
0xBE
,
0xEF
,
0xFE
,
0xED
}
;
IPAddress ip(
192
,
168
,
1
,
177
)
;
unsigned
int localPort =
8888
; // local port to listen on
// An EthernetUDP instance to let us send and receive packets over UDP
EthernetUDP Udp;
char packetBuffer[UDP_TX_PACKET_MAX_SIZE]
;
//buffer to hold incoming packet,
void
setup
(
)
{
// start the Ethernet and UDP:
Ethernet.begin
(mac,ip)
;
Udp.begin
(localPort)
;
}
void
loop
(
)
{
int packetSize = Udp.parsePacket
(
)
;
if
(packetSize)
{
Serial.print
(
"Received packet of size "
)
;
Serial.println
(packetSize)
;
Serial.print
(
"From "
)
;
IPAddress remote = Udp.remoteIP
(
)
;
for
(
int i =
0
; i <
4
; i++
)
{
Serial.print
(remote[i]
,
DEC
)
;
if
(i <
3
)
{
Serial.print
(
"."
)
;
}
}
Serial.print
(
", port "
)
;
Serial.println
(Udp.remotePort
(
)
)
;
// read the packet into packetBufffer
Udp.read
(packetBuffer,UDP_TX_PACKET_MAX_SIZE)
;
Serial.println
(
"Contents:"
)
;
Serial.println
(packetBuffer)
;
}
}
The text of the Arduino reference is licensed under a Creative Commons Attribution-ShareAlike 3.0 License. Code samples in the reference are released into the public domain.