/*
 UDPSendReceive.ino

 This sketch receives UDP message strings, prints them to the serial port
 and sends an "acknowledge" string back to the sender

 A Processing sketch is included at the end of file that can be used to send
 and received messages for testing with a computer.

 Here's using netcat to send udp
     echo -n "foo" | nc -4u -q1 192.168.1.177 8888

 created 21 Aug 2010
 by Michael Margolis

 modified 24 Feb 2014
 by Craig Hollabaugh

 This code is in the public domain.
*/


#include <Ethernet.h>
#include <EthernetUdp.h>         // UDP library from: bjoern@cs.stanford.edu 12/30/2008
#include <cstdint>

#define EMAC0_BASE              0x400EC000  // Ethernet Controller
#define EMAC_O_ADDR0H 0x00000040 // Ethernet MAC Address 0 High
#define EMAC_O_ADDR0L 0x00000044 // Ethernet MAC Address 0 Low
// Register
#define EMAC_O_ADDR1H 0x00000048 // Ethernet MAC Address 1 High
#define EMAC_O_ADDR1L 0x0000004C // Ethernet MAC Address 1 Low
#define EMAC_O_ADDR2H 0x00000050 // Ethernet MAC Address 2 High
#define EMAC_O_ADDR2L 0x00000054 // Ethernet MAC Address 2 Low
#define EMAC_O_ADDR3H 0x00000058 // Ethernet MAC Address 3 High
#define EMAC_O_ADDR3L 0x0000005C // Ethernet MAC Address 3 Low

// 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

// buffers for receiving and sending data
char packetBuffer[UDP_TX_PACKET_MAX_SIZE]; //buffer to hold incoming packet,
char  ReplyBuffer[] = "acknowledged\n";       // a string to send back

// An EthernetUDP instance to let us send and receive packets over UDP
EthernetUDP Udp;

char hex[16] = {'0', '1', '2', '3', '4', '5','6','7','8','9','A','B','C','D','E','F'};

void setup() {
  // start the Ethernet and UDP:
  Ethernet.begin(mac,ip);
  Udp.begin(localPort);

  Serial.begin(9600);
  Serial.println("UDPSendReceiveString setup");
  Serial.print("listening on ");
  ip.printTo(Serial);
  Serial.print(":");
  Serial.println(localPort);

  uint8_t b1, b2, b3, b4, b5, b6;

  b1 = (*((uint32_t*)(EMAC0_BASE + EMAC_O_ADDR0H))) & 0xff;
  b2 = (*((uint32_t*)(EMAC0_BASE + EMAC_O_ADDR0L))) & 0xff;
  b3 = (*((uint32_t*)(EMAC0_BASE + EMAC_O_ADDR1H))) & 0xff;
  b4 = (*((uint32_t*)(EMAC0_BASE + EMAC_O_ADDR1L))) & 0xff;
  b5 = (*((uint32_t*)(EMAC0_BASE + EMAC_O_ADDR2H))) & 0xff;
  b6 = (*((uint32_t*)(EMAC0_BASE + EMAC_O_ADDR2L))) & 0xff;

  Serial.print(hex[b1 >> 4]);
  Serial.print(hex[b1 & 0xf]);
  Serial.print(":");
  Serial.print(hex[b2 >> 4]);
  Serial.print(hex[b2 & 0xf]);
  Serial.print(":");
  Serial.print(hex[b3 >> 4]);
  Serial.print(hex[b3 & 0xf]);
  Serial.print(":");
  Serial.print(hex[b4 >> 4]);
  Serial.print(hex[b4 & 0xf]);
  Serial.print(":");
  Serial.print(hex[b5 >> 4]);
  Serial.print(hex[b5 & 0xf]);
  Serial.print(":");
  Serial.print(hex[b6 >> 4]);
  Serial.print(hex[b6 & 0xf]);
}

void loop() {
  // if there's data available, read a packet

  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);

    // 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);
}