From d7a21bd2471442c192a6ef701d8f5e461cf46048 Mon Sep 17 00:00:00 2001
From: aledand <air.alda@gmail.com>
Date: Tue, 15 Dec 2015 11:47:28 +0100
Subject: [PATCH 1/3] Update firmware.md

spark/firmware #766 PR companion
---
 src/content/reference/firmware.md | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/src/content/reference/firmware.md b/src/content/reference/firmware.md
index aba059b8cc..6a1046a9d5 100644
--- a/src/content/reference/firmware.md
+++ b/src/content/reference/firmware.md
@@ -3260,6 +3260,22 @@ UDP udp;
 udp.leaveMulticast();
 ```
 
+### isValid()
+
+Check if the previusly bind UDP socket is valid.
+
+```cpp
+
+// SYNTAX
+
+if (udp.isValid()) {
+   // seek available data ...
+} else {
+  // udp socket not valid	
+}
+
+```
+
 {{/if}}
 
 

From 126cb3355163e1a5ba312427333b7b503829573c Mon Sep 17 00:00:00 2001
From: aledand <air.alda@gmail.com>
Date: Tue, 15 Dec 2015 14:28:11 +0100
Subject: [PATCH 2/3] Update firmware.md

---
 src/content/reference/firmware.md | 48 +++++++++++++++++++++++++++----
 1 file changed, 42 insertions(+), 6 deletions(-)

diff --git a/src/content/reference/firmware.md b/src/content/reference/firmware.md
index 6a1046a9d5..19edf9a68e 100644
--- a/src/content/reference/firmware.md
+++ b/src/content/reference/firmware.md
@@ -3262,16 +3262,52 @@ udp.leaveMulticast();
 
 ### isValid()
 
-Check if the previusly bind UDP socket is valid.
+UDP reading APIs do not check for socket validity. On typical listening loop isValid() can be used to avoid waiting for ever for data no more coming.
 
 ```cpp
 
-// SYNTAX
+// EXAMPLE USAGE
+
+// UDP Port used for two way communication
+unsigned int localPort = 8888;
+
+// An UDP instance to let us send and receive packets over UDP
+UDP Udp;
+
+void setup() {
+  // start the UDP
+  Udp.begin(localPort);
+
+  // Print your device IP Address via serial
+  Serial.begin(9600);
+  Serial.println(WiFi.localIP());
+}
 
-if (udp.isValid()) {
-   // seek available data ...
-} else {
-  // udp socket not valid	
+void loop() {
+  if (Udp.isValid()) {
+		// Check if data has been received
+		if (Udp.parsePacket() > 0) {
+		
+			// Read first char of data received
+			char c = Udp.read();
+			
+			// Ignore other chars
+			Udp.flush();
+			
+			// Store sender ip and port
+			IPAddress ipAddress = Udp.remoteIP();
+			int port = Udp.remotePort();
+			
+			// Echo back data to sender
+			Udp.beginPacket(ipAddress, port);
+			Udp.write(c);
+			Udp.endPacket();
+		}
+  }
+  else { // UDP Sockect not valid, restart it 
+  	Udp.Stop();
+  	Udp.begin(localPort);
+  }
 }
 
 ```

From c6f0f77a8deb3c1e4a593ff91ac24abbc101215e Mon Sep 17 00:00:00 2001
From: aledand <air.alda@gmail.com>
Date: Tue, 15 Dec 2015 14:30:13 +0100
Subject: [PATCH 3/3] Update firmware.md

---
 src/content/reference/firmware.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/content/reference/firmware.md b/src/content/reference/firmware.md
index 19edf9a68e..9d588e1d69 100644
--- a/src/content/reference/firmware.md
+++ b/src/content/reference/firmware.md
@@ -3262,7 +3262,7 @@ udp.leaveMulticast();
 
 ### isValid()
 
-UDP reading APIs do not check for socket validity. On typical listening loop isValid() can be used to avoid waiting for ever for data no more coming.
+UDP reading APIs do not check for socket validity. On typical listening loop isValid() can be used to avoid waiting for ever for data will never come.
 
 ```cpp