Send and Receive UDP String

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1/*
2
3  WiFi UDP Send and Receive String
4
5 This sketch wait an UDP packet on localPort using a WiFi shield.
6
7 When a packet is received an Acknowledge packet is sent to the client on port remotePort
8
9 Circuit:
10
11 * WiFi shield attached
12
13 created 30 December 2012
14
15 by dlf (Metodo2 srl)
16
17 */
18
19#include <SPI.h>
20#include <WiFi.h>
21#include <WiFiUdp.h>
22
23int status = WL_IDLE_STATUS;
24char ssid[] = "yourNetwork"; //  your network SSID (name)
25char pass[] = "secretPassword";    // your network password (use for WPA, or use as key for WEP)
26int keyIndex = 0;            // your network key Index number (needed only for WEP)
27
28unsigned int localPort = 2390;      // local port to listen on
29
30char packetBuffer[255]; //buffer to hold incoming packet
31char  ReplyBuffer[] = "acknowledged";       // a string to send back
32
33WiFiUDP Udp;
34
35void setup() {
36
37  //Initialize serial and wait for port to open:
38
39  Serial.begin(9600);
40
41  while (!Serial) {
42
43    ; // wait for serial port to connect. Needed for native USB port only
44
45  }
46
47  // check for the presence of the shield:
48
49  if (WiFi.status() == WL_NO_SHIELD) {
50
51    Serial.println("WiFi shield not present");
52
53    // don't continue:
54
55    while (true);
56
57  }
58
59  String fv = WiFi.firmwareVersion();
60
61  if (fv != "1.1.0") {
62
63    Serial.println("Please upgrade the firmware");
64
65  }
66
67  // attempt to connect to Wifi network:
68
69  while (status != WL_CONNECTED) {
70
71    Serial.print("Attempting to connect to SSID: ");
72
73    Serial.println(ssid);
74
75    // Connect to WPA/WPA2 network. Change this line if using open or WEP network:
76
77    status = WiFi.begin(ssid);
78
79    // wait 10 seconds for connection:
80
81    delay(10000);
82
83  }
84
85  Serial.println("Connected to wifi");
86
87  printWifiStatus();
88
89  Serial.println("\nStarting connection to server...");
90
91  // if you get a connection, report back via serial:
92
93  Udp.begin(localPort);
94}
95
96void loop() {
97
98  // if there's data available, read a packet
99
100  int packetSize = Udp.parsePacket();
101
102  if (packetSize) {
103
104    Serial.print("Received packet of size ");
105
106    Serial.println(packetSize);
107
108    Serial.print("From ");
109
110    IPAddress remoteIp = Udp.remoteIP();
111
112    Serial.print(remoteIp);
113
114    Serial.print(", port ");
115
116    Serial.println(Udp.remotePort());
117
118    // read the packet into packetBufffer
119
120    int len = Udp.read(packetBuffer, 255);
121
122    if (len > 0) {
123
124      packetBuffer[len] = 0;
125
126    }
127
128    Serial.println("Contents:");
129
130    Serial.println(packetBuffer);
131
132    // send a reply, to the IP address and port that sent us the packet we received
133
134    Udp.beginPacket(Udp.remoteIP(), Udp.remotePort());
135
136    Udp.write(ReplyBuffer);
137
138    Udp.endPacket();
139
140  }
141}
142
143void printWifiStatus() {
144
145  // print the SSID of the network you're attached to:
146
147  Serial.print("SSID: ");
148
149  Serial.println(WiFi.SSID());
150
151  // print your WiFi shield's IP address:
152
153  IPAddress ip = WiFi.localIP();
154
155  Serial.print("IP Address: ");
156
157  Serial.println(ip);
158
159  // print the received signal strength:
160
161  long rssi = WiFi.RSSI();
162
163  Serial.print("signal strength (RSSI):");
164
165  Serial.print(rssi);
166
167  Serial.println(" dBm");
168}