how to acquire arduino ethercard udp receive data? - arduino

Question

I have a problem in accessing received udp string, I can get it by serial though. I just need to get my incoming udp data into a variable using the ethercard library in loop() function so I can use them in my program.Here's the code I'm working with:
#include <EtherCard.h>
#include <IPAddress.h>
#define STATIC 1 // set to 1 to disable DHCP (adjust myip/gwip values below)
#if STATIC
// ethernet interface ip address
static byte myip[] = { 192,168,1,200 };
// gateway ip address
static byte gwip[] = { 192,168,1,1 };
#endif
// ethernet mac address - must be unique on your network
static byte mymac[] = { 0x70,0x69,0x69,0x2D,0x30,0x31 };
byte Ethernet::buffer[500]; // tcp/ip send and receive buffer
//callback that prints received packets to the serial port
void udpSerialPrint(word port, byte ip[4], const char *data, word len) {
Serial.println(data);
}
void setup(){
Serial.begin(57600);
Serial.println("\n[backSoon]");
if (ether.begin(sizeof Ethernet::buffer, mymac, 10) == 0)
Serial.println( "Failed to access Ethernet controller");
#if STATIC
ether.staticSetup(myip, gwip);
#else
if (!ether.dhcpSetup())
Serial.println("DHCP failed");
#endif
ether.printIp("IP: ", ether.myip);
ether.printIp("GW: ", ether.gwip);
ether.printIp("DNS: ", ether.dnsip);
//register udpSerialPrint() to port 1337
ether.udpServerListenOnPort(&udpSerialPrint, 1337);
//register udpSerialPrint() to port 42.
ether.udpServerListenOnPort(&udpSerialPrint, 42);
}
void loop(){
//this must be called for ethercard functions to work.
ether.packetLoop(ether.packetReceive());
//? incoming = data; <--- this is my problem
//Serial.println(incoming);
}
It's just a slightly modified version of the UDPListener example that comes with the ethercard library.
Thank you

Answer 1

I'm still on a steep learning curve myself but have managed to get UDP talking between units so hope following helps. Suspect the quickest way would be to create a global variable such as:
char gUDPdata[30] = "";
then in your udpSerialPrint routine add the following for a quick and dirty result. This copies 'data' to a global variable that you can see in your main loop.
Serial.println(data);
data[0] = 0;
strcpy(data, gUDPdata);
then in your main loop following should produce same as Serial.print in the udpSerialPrint routine.
Serial.println(gUDPdata);