Damien Frost / Mbed 2 deprecated IoT_Ex

Example program to create IoT devices for a local network, which connect to a local server.

Dependencies:   WebSocketClient WiflyInterface mbed messages

This code is used in the second part of my Internet of Things (IoT) blog post available here. The code is fairly simple, but its real value is in its reliability. I have worked hard to try to make the wireless connection as reliable, and as fast, as possible. There are a few lines of code that must be modified before it will work correctly, and those are described in the following Wiki pages.

It is designed to work with a Python WebSocket Server running on a PC, the source code of which is available here.

Once operating with the server, each microcontroller, or IoT device, will broadcast a counter and its internal temperature to your WebSocket Server.

Diff: source/globals.cpp

Revision:
2:7abdaa5a9209
Parent:
1:4403f2ed1c1f
Child:
3:f20e114eb2ee
--- a/source/globals.cpp	Tue Oct 04 13:19:19 2016 +0000
+++ b/source/globals.cpp	Tue Oct 04 13:59:13 2016 +0000
@@ -21,6 +21,7 @@
 Serial          pc(USBTX, USBRX);
 InterruptIn     UIBut1(USER_BUTTON);
 Timer           DisplayTimer;
+DigitalOut      Led(LED1);
 
 WiflyInterface eth(D8, D2, D6, LED1, wifissid, wifipassword, WPA2);
 
@@ -131,22 +132,29 @@
 void ReceiveNetworkData(unsigned int * wifi_cmd, unsigned int * var, float * value){
     char msg_buffer[CHARMSGBUFF];
     char msg_buffer2[CHARMSGBUFF];
-    // Check for data on the websocket:
-    if(ws.readmsg(msg_buffer)){
-        INFO("Received: %s", msg_buffer);
-        sscanf(msg_buffer, "%d,%s", wifi_cmd, msg_buffer2);
-        if(*wifi_cmd == CHANGEVAR_WIFI_CMD){
-            // Get two more values:
-            sscanf(msg_buffer2, "%d,%f", var, value);
+    int resp;
+    if(IotStatus.CheckFlag(SF_SERVERCONNECTED)){
+        // Check for data on the websocket:
+        resp = ws.readmsg(msg_buffer);
+        if(resp == 1){
+            INFO("Received: %s", msg_buffer);
+            sscanf(msg_buffer, "%d,%s", wifi_cmd, msg_buffer2);
+            if(*wifi_cmd == CHANGEVAR_WIFI_CMD){
+                // Get two more values:
+                sscanf(msg_buffer2, "%d,%f", var, value);
+            }else{
+                // Get one:
+                sscanf(msg_buffer2, "%f", value);
+            }
+        }else if(resp == -1){
+            // Connection to the server is lost:
+            IotStatus.ClearFlag(SF_SERVERCONNECTED);
         }else{
-            // Get one:
-            sscanf(msg_buffer2, "%f", value);
+            //DBG("Did not receive anything :(\n\r");
+            *wifi_cmd = NO_WIFI_CMD;
+            *var = 0;
+            *value = 0.0f;
         }
-    }else{
-        //DBG("Did not receive anything :(\n\r");
-        *wifi_cmd = NO_WIFI_CMD;
-        *var = 0;
-        *value = 0.0f;
     }
     return;
 }