main.cpp

00001 /*
00002  * (c) Copyright 2012 EVRYTHNG Ltd London / Zurich
00003  * www.evrythng.com
00004  *
00005  * --- DISCLAIMER ---
00006  *
00007  * EVRYTHNG provides this source code "as is" and without warranty of any kind,
00008  * and hereby disclaims all express or implied warranties, including without
00009  * limitation warranties of merchantability, fitness for a particular purpose,
00010  * performance, accuracy, reliability, and non-infringement.
00011  *
00012  *
00013  * --- READ ME ---
00014  *
00015  * This is a demo application that uses EVRYTHNG's mbed wrapper to read and
00016  * write value to EVRYTHNG's engine. Please refer to the online documentation
00017  * available at http://dev.evrythng.com/mbed.
00018  *
00019  *
00020  * Author: Michel Yerly
00021  *
00022  */
00023 
00024 #include "mbed.h"
00025 #include "EthernetInterface.h"
00026 #include <time.h>
00027 #include "EvrythngApi.h"
00028 #include "util.h"
00029 #include "eventqueue.h"
00030 
00031 /*
00032  * Configuration
00033  */
00034  
00035 // Your EVRYTHNG api key.
00036 const char* API_KEY = "";
00037 
00038 // Your thng id, the one that represents your mbed device.
00039 const char* THNG_ID = "";
00040 
00041 // The property you want values to be pushed to.
00042 const char* THNG_PROP_SET = "prop3";
00043 
00044 // The property you want values to be read from.
00045 const char* THNG_PROP_GET = "prop3";
00046 
00047 
00048 
00049 DigitalOut led1(LED1);
00050 DigitalOut led2(LED2);
00051 DigitalOut led3(LED3);
00052 DigitalOut led4(LED4);
00053 
00054 static char displayVal = 0;
00055 
00056 /*
00057  * Displays a value between 0 and 15 as binary on the 4 LEDs.
00058  */
00059 void display(char x)
00060 {
00061     led1 = x & (char)8 ? 1 : 0;
00062     led2 = x & (char)4 ? 1 : 0;
00063     led3 = x & (char)2 ? 1 : 0;
00064     led4 = x & (char)1 ? 1 : 0;
00065     displayVal = x;
00066 }
00067 
00068 /*
00069  * Flashes the 4 LEDs, and restores the state of the last display().
00070  */
00071 void flash()
00072 {
00073     char s = displayVal;
00074     for (int i = 0; i < 2; ++i) {
00075         display(0x0F);
00076         wait(0.1);
00077         display(0x00);
00078         wait(0.1);
00079     }
00080     display(s);
00081 }
00082 
00083 /* 
00084  * Function to get the number of milliseconds elapsed since the system startup.
00085  * It is imprecise and if called repetitively and quickly, it may always return
00086  * the same result. It MUST be called at least every 30 minutes.
00087  * NOTE: I'm not proud of it.
00088  */
00089 int64_t getMillis()
00090 {
00091     static Timer tmr;
00092     static int64_t clk = 0;
00093     
00094     tmr.stop();
00095     clk += tmr.read_ms();
00096     tmr.reset();
00097     tmr.start();
00098     
00099     char str[21];
00100     char* end;
00101     sprinti64(str, clk, &end);
00102     *end = '\0';
00103     dbg.printf("%s ", str);
00104     
00105     return clk;
00106 }
00107 
00108 /*
00109  * Entry point.
00110  *
00111  * This demo application uses an event loop to set and get property values
00112  * on EVRYTHNG engine at given intervals.
00113  */
00114 int main()
00115 {
00116     dbg.printf("Initializing ethernet interface\r\n");
00117     EthernetInterface eth;
00118     eth.init(); //Use DHCP
00119     eth.connect();
00120     dbg.printf("IP address: %s\r\n", eth.getIPAddress());
00121 
00122     EvrythngApi api(API_KEY);
00123 
00124     // intervals in ms
00125     const int SET_INTERVAL = 5000;
00126     const int GET_INTERVAL = 2000;
00127 
00128     int curVal = 0;
00129     display(curVal);
00130 
00131     int putVal = 0;
00132     char strPutVal[3];  
00133     int64_t timestamp = 1345736694000LL; // 2012-08-23 10:44:54am EST
00134 
00135     EventQueue eventQueue;
00136     eventQueue.put(getMillis()+GET_INTERVAL, EVT_GET_PROP);
00137     eventQueue.put(getMillis()+SET_INTERVAL, EVT_SET_PROP);
00138 
00139     while (!eventQueue.empty()) {
00140         EventType event = eventQueue.waitNext(getMillis());
00141 
00142         switch (event) {
00143 
00144             case EVT_SET_PROP:
00145 
00146                 eventQueue.put(SET_INTERVAL + getMillis(), EVT_SET_PROP);
00147 
00148                 putVal = (putVal + 1) & 0xF;
00149                 sprintf(strPutVal, "%d", putVal);
00150                 timestamp++;
00151                 api.setThngPropertyValue(THNG_ID, THNG_PROP_SET, string(strPutVal), timestamp);
00152 
00153                 break;
00154 
00155             case EVT_GET_PROP:
00156 
00157                 eventQueue.put(GET_INTERVAL + getMillis(), EVT_GET_PROP);
00158 
00159                 string v;
00160                 int r = api.getThngPropertyValue(THNG_ID, THNG_PROP_GET, v);
00161                 if (r == 0) {
00162                     flash();
00163                     int newVal = atoi(v.c_str());
00164                     if (newVal != curVal) {
00165                         curVal = newVal;
00166                         display(curVal);
00167                     }
00168                 }
00169                 break;
00170         }
00171     }
00172 
00173     dbg.printf("Disconnecting ethernet interface\r\n");
00174     eth.disconnect();
00175 
00176     dbg.printf("Done.\r\n");
00177     while(1) {}
00178 }