Merge pull request #29 from JiriBilek/UDP_Multicast

Add UDP Multicast support

README.md

@@ -7,6 +7,10 @@ The library allows Arduino to be client or server on the WiFi network.
 
 ## News
 
+#### 2021-01-25
+
+Added UDP Multicast support
+
 #### 2021-01-02
 
 Fixed a bug with closing server connection when closing asynchronously opened another client.
@@ -255,11 +259,14 @@ Default constuctor.
 - **uint8_t begin(uint16_t port)**
 Initializes the instance, starts listening on specified *port*. Returns 1 if successful, 0 on error.
 
+- **uint8_t begin(uint16_t multicastIP, uint16_t port)**
+Initializes the instance, starts listening on specified *port* for multicast messages from *multicastIP* address. Returns 1 if successful, 0 on error.
+
 - **void stop()**
 Stops listening on the UDP port, frees the UDP socket used.
 
 - **int beginPacket(IPAddress ip, uint16_t port)**
-Starts building up a packet to send to the remote host specific in *ip* and *port*. Returns 1 if successful, 0 if there was a problem with the connection.
+Starts building up a packet to send to the remote host specific in *ip* and *port*. Returns 1 if successful, 0 if there was a problem with the connection. This function works for both unicast and multicast communication.
 
 - **int endPacket()**
 Finishes the packet and sends it. Returns 1 if the packet was sent successfully, 0 if there was an error.
@@ -306,6 +313,12 @@ Simple mqtt messaging.
 - **UdpNTPClient**
 Reads current time and date from a NTP server.
 
+- **UDP_Multicast_Transmitter**
+Peridically transmits a short messaage via UDP multicast.
+
+- **UDP_Multicast_Receiver**
+Listens for multicast messages, reads them and prints them out.
+
 More examples to come soon. But you can easily use the ones from WiFi library. Don't forget to add a line *WiFiSpi.init();* before using other library functions.
 
 ## Debugging
@@ -314,8 +327,7 @@ For some debugging information on Serial output uncomment line 23 (#define _DEBU
 
 ## ToDo and Wish Lists
 
-- TLS connection
-- SPI protocol optimization
+- more SPI protocol optimization
 
 ## Credits
 

examples/UDP_Multicast_Receiver/UDP_Multicast_Receiver.ino

@@ -0,0 +1,137 @@
+/*
+  Receive multicast UDP packets
+
+  This sketch receives multicast UDP packets from address 239.1.74.74, port 7474
+  Uses WiFi ESP8266 module.
+
+  This example is written for a network using WPA encryption.
+
+  Circuit:
+   1. On ESP8266 must be running (flashed) WiFiSPIESP application.
+
+   2. Connect the Arduino to the following pins on the esp8266:
+
+            ESP8266         |
+    GPIO    NodeMCU   Name  |   STM32F103
+   ===================================
+     15       D8       SS   |   PA4
+     13       D7      MOSI  |   PA7
+     12       D6      MISO  |   PA6
+     14       D5      SCK   |   PA5
+     RESET                  |   PB12
+
+    Note: If the ESP is booting at the moment when the SPI Master (i.e. Arduino) has the Select line HIGH (deselected)
+    the ESP8266 WILL FAIL to boot!
+
+*/
+
+#include <WiFiSpi.h>
+
+char ssid[] = "your ssid here"; //  your network SSID (name)
+char pass[] = "your password here";    // your network password
+
+#if defined(MCU_STM32F103C8)
+const uint8_t RESET_PIN = PB12;  // For STM32F103
+#endif
+
+// Note: remoteIP is a multicast address, it should begin with 239.x.x.x or some other
+// appropriate multicast address.
+// It's not the same as your local IP address (192.168.x.x, for example)!
+IPAddress remoteIP(239, 1, 74, 74);
+
+// The remote port must be otherwise unused on any machine that is receiving these packets
+int remotePort = 7474;
+
+// Create the UDP object
+WiFiSpiUdp udp;
+
+void setup() {
+#if defined(MCU_STM32F103C8)
+  // Reset PIN
+  pinMode(RESET_PIN, OUTPUT);
+  digitalWrite(RESET_PIN, HIGH);
+#endif
+
+  //Initialize serial and wait for port to open:
+  Serial.begin(115200);
+  while (!Serial.available()) {
+    ; // wait for serial port to connect. Needed for native USB port only
+  }
+
+  Serial.println("Reset ESP8266");
+
+#if defined(MCU_STM32F103C8)
+  // Reset the ESP
+  digitalWrite(RESET_PIN, LOW);
+  delay(100);
+  digitalWrite(RESET_PIN, HIGH);
+  delay(500);
+#endif
+
+  // Initialize the library
+  WiFiSpi.init(SS, 100000);
+
+  // check for the presence of the shield:
+  if (WiFiSpi.status() == WL_NO_SHIELD) {
+    Serial.println("Error in communication with the ESP board, halted");
+    WiFiSpi.status();
+    // don't continue:
+    while (true);
+  }
+
+  if (! WiFiSpi.checkProtocolVersion())
+    Serial.println("Please upgrade the firmware");
+
+  // attempt to connect to Wifi network:
+  uint8_t status;
+  do {
+    Serial.print("Attempting to connect to SSID: ");
+    Serial.println(ssid);
+    // Connect to WPA/WPA2 network.
+    status = WiFiSpi.begin(ssid, pass);
+  } while (status != WL_CONNECTED);
+
+  Serial.println("Connected to wifi");
+
+  // Start listening for multicast messages
+  udp.beginMulticast(remoteIP, remotePort);
+}
+
+void loop() {
+  // If there's data available, read a packet
+  int packetSize = udp.parsePacket();
+
+  // If there's data, read them and print them
+  if (packetSize > 0) {
+    Serial.print("Incoming packet, size=");  Serial.println(packetSize);
+    while (udp.available()) {
+      int inp = udp.read();
+      if (inp >= ' ' && inp <= 0x7f)
+        Serial.print(char(inp));
+      else {
+        Serial.print(inp);  Serial.print(' ');
+      }
+    }
+    Serial.println();
+  }
+
+  delay(100);
+}
+
+
+void printWifiStatus() {
+  // print the SSID of the network you're attached to:
+  Serial.print("SSID: ");
+  Serial.println(WiFiSpi.SSID());
+
+  // print your WiFi shield's IP address:
+  IPAddress ip = WiFiSpi.localIP();
+  Serial.print("IP Address: ");
+  Serial.println(ip);
+
+  // print the received signal strength:
+  long rssi = WiFiSpi.RSSI();
+  Serial.print("signal strength (RSSI): ");
+  Serial.print(rssi);
+  Serial.println(" dBm");
+}

examples/UDP_Multicast_Transmitter/UDP_Multicast_Transmitter.ino

@@ -0,0 +1,146 @@
+/*
+  Transmit multicast UDP packets
+
+  This sketch transmits multicast UDP packets to address 239.1.74.74, port 7474
+  Uses WiFi ESP8266 module.
+
+  This example is written for a network using WPA encryption.
+
+  Circuit:
+   1. On ESP8266 must be running (flashed) WiFiSPIESP application.
+
+   2. Connect the Arduino to the following pins on the esp8266:
+
+            ESP8266         |
+    GPIO    NodeMCU   Name  |   STM32F103
+   ===================================
+     15       D8       SS   |   PA4
+     13       D7      MOSI  |   PA7
+     12       D6      MISO  |   PA6
+     14       D5      SCK   |   PA5
+     RESET                  |   PB12
+
+    Note: If the ESP is booting at the moment when the SPI Master (i.e. Arduino) has the Select line HIGH (deselected)
+    the ESP8266 WILL FAIL to boot!
+
+*/
+
+#include <WiFiSpi.h>
+
+char ssid[] = "your ssid here";  //  your network SSID (name)
+char pass[] = "your password here";    // your network password
+
+#if defined(MCU_STM32F103C8)
+const uint8_t RESET_PIN = PB12;
+#endif
+
+// Note: remoteIP is a multicast address, it should begin with 239.x.x.x or some other
+// appropriate multicast address.
+// It's not the same as your local IP address (192.168.x.x, for example)!
+IPAddress remoteIP(239, 1, 74, 74);
+
+// The remote port must be otherwise unused on any machine that is receiving these packets
+int remotePort = 7474;
+
+// Create the UDP object
+WiFiSpiUdp udp;
+
+void setup() {
+#if defined(MCU_STM32F103C8)
+  // Reset PIN
+  pinMode(RESET_PIN, OUTPUT);
+  digitalWrite(RESET_PIN, HIGH);
+#endif
+
+  //Initialize serial and wait for port to open:
+  Serial.begin(115200);
+  while (!Serial.available()) {
+    ; // wait for serial port to connect. Needed for native USB port only
+  }
+
+  Serial.println("Reset ESP8266");
+
+#if defined(MCU_STM32F103C8)
+  // Reset the ESP
+  digitalWrite(RESET_PIN, LOW);
+  delay(100);
+  digitalWrite(RESET_PIN, HIGH);
+  delay(500);
+#endif
+
+  // Initialize the library
+  WiFiSpi.init(SS, 100000);
+
+  // check for the presence of the shield:
+  if (WiFiSpi.status() == WL_NO_SHIELD) {
+    Serial.println("Error in communication with the ESP board, halted");
+    WiFiSpi.status();
+    // don't continue:
+    while (true);
+  }
+
+  if (! WiFiSpi.checkProtocolVersion())
+    Serial.println("Please upgrade the firmware");
+
+  // attempt to connect to Wifi network:
+  uint8_t status;
+  do {
+    Serial.print("Attempting to connect to SSID: ");
+    Serial.println(ssid);
+    // Connect to WPA/WPA2 network.
+    status = WiFiSpi.begin(ssid, pass);
+  } while (status != WL_CONNECTED);
+
+  Serial.println("Connected to wifi");
+
+  // Start UDP communication. No IP needed, because we are transmitting data
+  udp.begin(0);
+}
+
+void loop() {
+  static uint16_t counter = 0;  // The payload is only a simple counter
+
+  // via multicast we send the counter as the UDP message
+  if (udp.beginPacket(remoteIP, remotePort) == 1) {
+    uint8_t buffer[2];
+
+    ++counter;
+    buffer[0] = counter >> 8;
+    buffer[1] = (counter && 0xff);
+
+    // Write the payload
+    udp.write(buffer, sizeof(buffer));
+
+    // Send the packet
+    if (udp.endPacket() == 1) {
+      // Success
+      Serial.println(counter);
+    }
+    else {
+      Serial.println("send failed");
+    }
+  }
+  else {
+    Serial.println("open failed");
+  }
+
+  delay(1000);
+}
+
+
+void printWifiStatus() {
+  // print the SSID of the network you're attached to:
+  Serial.print("SSID: ");
+  Serial.println(WiFiSpi.SSID());
+
+  // print your WiFi shield's IP address:
+  IPAddress ip = WiFiSpi.localIP();
+  Serial.print("IP Address: ");
+  Serial.println(ip);
+
+  // print the received signal strength:
+  long rssi = WiFiSpi.RSSI();
+  Serial.print("signal strength (RSSI):");
+  Serial.print(rssi);
+  Serial.println(" dBm");
+}

src/WiFiSpi.cpp

@@ -33,7 +33,7 @@ extern "C" {
 }
 
 // Protocol version
-const char *WiFiSpiClass::protocolVer = "0.2.3";
+const char *WiFiSpiClass::protocolVer = "0.2.4";
 
 // Hardware reset pin
 int8_t WiFiSpiClass::hwResetPin = -1;
@@ -69,7 +69,7 @@ uint8_t WiFiSpiClass::getSocket()
     for (uint8_t i = 0; i < MAX_SOCK_NUM; ++i)
     {
         if (WiFiSpiClass::_state[i] == NA_STATE)  // _state is for both server and client
-             return i;
+			return i;
     }
     return SOCK_NOT_AVAIL;
 }

src/WiFiSpiUdp.cpp

@@ -57,6 +57,27 @@ uint8_t WiFiSpiUdp::begin(uint16_t port)
     return 0;
 }
 
+/*
+ * Starts WiFiSpiUdp socket, listening at port PORT for multicast messages from IP
+ * Returns 1 if successful, 0 on failure
+ */
+uint8_t WiFiSpiUdp::beginMulticast(IPAddress ip, uint16_t port)
+{
+    uint8_t sock = WiFiSpiClass::getSocket();
+    if (sock != SOCK_NOT_AVAIL)
+    {
+        if (ServerSpiDrv::startServerMulticast(uint32_t(ip), port, sock))
+        {
+            WiFiSpiClass::_server_port[sock] = port;
+            WiFiSpiClass::_state[sock] = sock;
+            _sock = sock;
+            _port = port;
+            return 1;
+        }
+    }
+    return 0;
+}
+
 /* 
  *  Returns number of bytes available in the current packet
  */
@@ -211,4 +232,4 @@ uint16_t WiFiSpiUdp::remotePort()
     else
         return 0;
 }
-
+