Send and Receive UDP String
This tutorial waits for a UDP packet on a local port. When a valid packet is received, an acknowledge packet is sent back to the client on a specified outgoing port. It relies on a WiFi connection made to your WiFi equipped board.
Hardware Required
Circuit
The WiFi module is integrated on your board and you don't need any special circuitry to get this tutorial to work.
Arduino MKR WiFi 1010
Arduino MKR VIDOR 4000
Arduino UNO WiFi Rev.2
Please note: these three boards use dedicated pins to communicate and select the WiFi module, therefore you have no restriction in the usage of the available digital pins connected to the header pins.
Code
You should have access to a 802.11b/g wireless network that connects to the internet for this example. You will need to change the network settings in the sketch to correspond to your particular networks SSID.
/*
WiFi UDP Send and Receive String
This sketch wait an UDP packet on localPort using the WiFi module.
When a packet is received an Acknowledge packet is sent to the client on port remotePort
created 30 December 2012
by dlf (Metodo2 srl)
*/
#include <SPI.h>
#include <WiFiNINA.h>
#include <WiFiUdp.h>
int status = WL_IDLE_STATUS;
#include "arduino_secrets.h"
///////please enter your sensitive data in the Secret tab/arduino_secrets.h
char ssid[] = SECRET_SSID; // your network SSID (name)
char pass[] = SECRET_PASS; // your network password (use for WPA, or use as key for WEP)
int keyIndex = 0; // your network key Index number (needed only for WEP)
unsigned int localPort = 2390; // local port to listen on
char packetBuffer[255]; //buffer to hold incoming packet
char ReplyBuffer[] = "acknowledged"; // a string to send back
WiFiUDP Udp;
void setup() {
//Initialize serial 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 the WiFi module:
if (WiFi.status() == WL_NO_MODULE) {
Serial.println("Communication with WiFi module failed!");
// don't continue
while (true);
}
String fv = WiFi.firmwareVersion();
if (fv < "1.0.0") {
Serial.println("Please upgrade the firmware");
}
// attempt to connect to Wifi network:
while (status != WL_CONNECTED) {
Serial.print("Attempting to connect to SSID: ");
Serial.println(ssid);
// Connect to WPA/WPA2 network. Change this line if using open or WEP network:
status = WiFi.begin(ssid, pass);
// wait 10 seconds for connection:
delay(10000);
}
Serial.println("Connected to wifi");
printWifiStatus();
Serial.println("\nStarting connection to server...");
// if you get a connection, report back via serial:
Udp.begin(localPort);
}
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 remoteIp = Udp.remoteIP();
Serial.print(remoteIp);
Serial.print(", port ");
Serial.println(Udp.remotePort());
// read the packet into packetBufffer
int len = Udp.read(packetBuffer, 255);
if (len > 0) {
packetBuffer[len] = 0;
}
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();
}
}
void printWifiStatus() {
// print the SSID of the network you're attached to:
Serial.print("SSID: ");
Serial.println(WiFi.SSID());
// print your board's IP address:
IPAddress ip = WiFi.localIP();
Serial.print("IP Address: ");
Serial.println(ip);
// print the received signal strength:
long rssi = WiFi.RSSI();
Serial.print("signal strength (RSSI):");
Serial.print(rssi);
Serial.println(" dBm");
}
WiFi UDP Send and Receive String
This sketch wait an UDP packet on localPort using the WiFi module.
When a packet is received an Acknowledge packet is sent to the client on port remotePort
created 30 December 2012
by dlf (Metodo2 srl)
*/
#include <SPI.h>
#include <WiFiNINA.h>
#include <WiFiUdp.h>
int status = WL_IDLE_STATUS;
#include "arduino_secrets.h"
///////please enter your sensitive data in the Secret tab/arduino_secrets.h
char ssid[] = SECRET_SSID; // your network SSID (name)
char pass[] = SECRET_PASS; // your network password (use for WPA, or use as key for WEP)
int keyIndex = 0; // your network key Index number (needed only for WEP)
unsigned int localPort = 2390; // local port to listen on
char packetBuffer[255]; //buffer to hold incoming packet
char ReplyBuffer[] = "acknowledged"; // a string to send back
WiFiUDP Udp;
void setup() {
//Initialize serial 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 the WiFi module:
if (WiFi.status() == WL_NO_MODULE) {
Serial.println("Communication with WiFi module failed!");
// don't continue
while (true);
}
String fv = WiFi.firmwareVersion();
if (fv < "1.0.0") {
Serial.println("Please upgrade the firmware");
}
// attempt to connect to Wifi network:
while (status != WL_CONNECTED) {
Serial.print("Attempting to connect to SSID: ");
Serial.println(ssid);
// Connect to WPA/WPA2 network. Change this line if using open or WEP network:
status = WiFi.begin(ssid, pass);
// wait 10 seconds for connection:
delay(10000);
}
Serial.println("Connected to wifi");
printWifiStatus();
Serial.println("\nStarting connection to server...");
// if you get a connection, report back via serial:
Udp.begin(localPort);
}
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 remoteIp = Udp.remoteIP();
Serial.print(remoteIp);
Serial.print(", port ");
Serial.println(Udp.remotePort());
// read the packet into packetBufffer
int len = Udp.read(packetBuffer, 255);
if (len > 0) {
packetBuffer[len] = 0;
}
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();
}
}
void printWifiStatus() {
// print the SSID of the network you're attached to:
Serial.print("SSID: ");
Serial.println(WiFi.SSID());
// print your board's IP address:
IPAddress ip = WiFi.localIP();
Serial.print("IP Address: ");
Serial.println(ip);
// print the received signal strength:
long rssi = WiFi.RSSI();
Serial.print("signal strength (RSSI):");
Serial.print(rssi);
Serial.println(" dBm");
}
See Also:
- WiFi NINA library – Your reference for the WiFi NINA Library.
- Arduino MKR WiFi 1010 – Product details for the Arduino MKR WiFi 1010 board.
- Arduino MKR VIDOR 4000 – Product details for the Arduino MKR VIDOR 4000 board.
- Arduino UNO WiFi Rev.2 – Product details for the Arduino UNO WiFi Rev.2 board.
- AP_SimpleWebServer : A simple web server to manage a LED with AP feature
- ConnectNoEncryption : Demonstrates how to connect to an open network
- ConnectWithWEP : Demonstrates how to connect to a network that is encrypted with WEP
- ConnectWithWPA : Demonstrates how to connect to a network that is encrypted with WPA2 Personal
- ScanNetworks : Displays all WiFi networks in range
- ScanNetworksAdwanced : Displays all WiFi networks, also the encrypted ones, in range
- SimpleWebServerWiFi : A simple web server to manage a LED
- WiFiChatServer : Set up a simple chat server
- WiFiPing : Demonstrates how to ping a website or IP address
- WiFiSSLClient : Connect to a website using SSL
- UdpNTPClient : Query a Network Time Protocol (NTP) server using UDP
- WiFiWebClient : Connect to a remote webserver
- WiFiWebClientRepeating : Make repeated HTTP calls to a webserver
- WiFiWebServer : Serve a webpage from the WiFi module
Last revision 2018/07/12 by SM
