Hi all
I have been battling away on a project where I want to send simple temperature values directly from one arduino to another arduino, both with W1500 ethernet shields attached. To start I am simply trying to send "hello world" from one to the other and having the receiver display in the serial port.
I have a crossover cable between the two arduinos, and I have confirmed both the sheilds are connected and ethernet cables are connected correctly.
I have been unable to receive any communication on the receiver side, the packetsize has been 0 at all times. I would think the transmitter is working correctly, since the TX LED flashed continuously and "Message Sent" is repeatedly displayed on the serial port. I therefore believe it to be the receiver. Switching the ethernet shields has the same results.
Any guidance would be greatly appreciated! Thanks in advance.
Transmitter
//Transmitter Code
//Observations: Seems to work. TX light on shield flashes continuously.
#include <SPI.h>
#include <Ethernet.h>
#include <EthernetUdp.h>
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED }; //Destination MAC address
IPAddress ip(192, 168, 0, 25); //Local IP address
IPAddress destIp(192,168,0,21); //Destination ip address
unsigned int localPort = 5000; // local port to listen on
unsigned int destPort = 5005; //Destination port
EthernetUDP Udp; //Instance of UDP
char message[] = "Hello World!";
/*Initialise the sending of data using UDP over ethernet*/
void setup() {
Serial.begin(9600);
Ethernet.begin(mac,ip); // start the Ethernet and UDP:
Udp.begin(localPort);
}
void loop() {
Udp.beginPacket(destIp, destPort); //Start Packet
Udp.write(message);
Udp.endPacket(); //Close Packet
Serial.println("Message Sent"); //Send Confirmation message
delay(10);
}
Receiver
#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, 0, 21);
unsigned int localPort = 5005; // local port to listen on
// buffers for receiving and sending data
char packetBuffer[UDP_TX_PACKET_MAX_SIZE]; // buffer to hold incoming packet,
char ReplyBuffer[] = "acknowledged"; // a string to send back
// An EthernetUDP instance to let us send and receive packets over UDP
EthernetUDP Udp;
void setup() {
// start the Ethernet
Ethernet.begin(mac, ip);
// Open serial communications and wait for port to open:
Serial.begin(9600);
while (!Serial) {
; // wait for serial port to connect. Needed for native USB port only
}
// Check for Ethernet hardware present
if (Ethernet.hardwareStatus() == EthernetNoHardware) {
Serial.println("Ethernet shield was not found. Sorry, can't run without hardware. :(");
while (true) {
delay(1); // do nothing, no point running without Ethernet hardware
}
}
if (Ethernet.linkStatus() == LinkOFF) {
Serial.println("Ethernet cable is not connected.");
}
// start UDP
Udp.begin(localPort);
Serial.print("hereee ");
delay(10);
}
void loop() {
// if there's data available, read a packet
delay(100);
int packetSize = Udp.parsePacket();
// Serial.println(packetSize);
delay(10);
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);
// send a reply to the IP address and port that sent us the packet we received
Udp.beginPacket(Udp.remoteIP(), Udp.remotePort());
Udp.write(ReplyBuffer);
Udp.endPacket();
}
delay(10);
}
