main.cpp

00001 /****************************************************************************************/
00002 /*                               INTERNET OF THINGS ASSIGNMENT 6                        */
00003 /*This assignment implements a thermostat which turns ON/OFF depending on the set and   */
00004 /*current temperature. The thermostat can be turned ON/OFF by following ways:           */
00005 /*                    1. Joustick up button on the application board.                   */
00006 /*                    2. Depending on if there is movement or not                       */
00007 /*                    3. Remotely through wifly(Telnet)                                 */
00008 /****************************************************************************************/
00009 
00010 #include "mbed.h"
00011 #include "rtos.h"
00012 #include "C12832_lcd.h"
00013 #include "NTPClient.h"
00014 #include "WiflyInterface.h"
00015 #include "LM75B.h"
00016 #include "DebouncedIn.h"
00017 #include "MMA7660.h"
00018 
00019 #define SEC 1000                     //macro for no. of msec in sec
00020 #define MIN 60*SEC                  //macro for no. of msec in min
00021 #define hys 3
00022 #define TIME 20                    //Time after which system should turn OFF if
00023                                    //no movement detected
00024 #define ECHO_SERVER_PORT   7       //Server port for HTTP client.
00025 
00026 Mutex LCD;
00027 C12832_LCD lcd;
00028 Serial pc (USBTX,USBRX);
00029 LM75B current(p28,p27);
00030 MMA7660 MMA(p28,p27);
00031 BusOut move(p23,p24,p25);
00032 
00033 //System ON/OFF
00034 BusIn heat_on (p16,p13); 
00035                                       
00036 //Increase Temperature
00037 DebouncedIn temp_up (p15); 
00038 
00039 //Decrease Temperature                                    
00040 DebouncedIn temp_down (p12);                                   
00041 
00042 //System ON/OFF LED
00043 DigitalOut thermostat (LED1);
00044 
00045 //Heater ON/OFF LED. This can be furthur connected to the relay                                  
00046 DigitalOut heater (LED2);                                  
00047 
00048 
00049 int temp = 10;
00050 bool status = 0;
00051 
00052 void update_lcd(void const *args);       //Thread 1
00053 void Thermostat_logic (void const *args);      //Thread 2
00054 void check_movement(void const *args);      //Thread 3
00055 
00056 bool no_move;
00057 float acc_x = MMA.x();
00058 float acc_y = MMA.y();
00059 float acc_z = MMA.z();
00060 float acc_x_old,acc_y_old,acc_z_old;
00061 bool wifly_on = 0;
00062 
00063 WiflyInterface wifly(p9, p10, p30, p29, "MY_WIFI", "", NONE);
00064 
00065 /****************************************************************************************/
00066 /*Thread update_lcd: This thread is used to update the lcd. The LCD will dispaly current*/
00067 /*time, Set temperature and the actual temperature. If the system is OFF lcd will show  */
00068 /*current time and message 'System OFF'                                                 */
00069 /****************************************************************************************/
00070 void update_lcd(void const *args)
00071 {
00072     set_time(1391739990); 
00073     while (true) {
00074     time_t seconds = time(NULL);
00075     LCD.lock();
00076     lcd.locate(0,0);
00077     lcd.printf("%s",ctime(&seconds));
00078     lcd.locate(0,10);
00079     if (status) {                                          
00080             lcd.printf("Current: %.2f",current.read());
00081             lcd.locate(1,20);
00082             lcd.printf("Set: %d",temp);
00083         } else {                                               
00084             lcd.printf("System OFF");
00085         }     
00086     LCD.unlock();
00087     Thread::wait(200);        //LCD will update after every 200msec.
00088     }
00089 }
00090 /****************************************************************************************/
00091 
00092 /****************************************************************************************/
00093 /*Thread: thermostat logic: This thread implements the logic of the thermostat. It turns*/
00094 /*ON/OFF the thermostat depending on temperature, movement and the web control. It also */
00095 /*allows the user to set the temperature from the push button switches. The setting of  */
00096 /*temperature can also be done remotely through xively. Currently the program just      */
00097 /*controls turning ON/OFF the system remotely.                                          */
00098 /****************************************************************************************/
00099 void Thermostat_logic(void const *args)
00100 {
00101     while (true) {
00102         if (heat_on == 0x2  || wifly_on || !no_move) 
00103         {
00104             thermostat = 1;                                    
00105             status = 1;   
00106             wifly_on = 1;                                     
00107         } else if ( wifly_on == 0 ){              
00108             thermostat = 0;                                    
00109             heater = 0;                                       
00110             status = 0;   
00111             wifly_on = 0;                                    
00112         }
00113         else if (heat_on == 0x1 || no_move ) {                
00114             thermostat = 0;                                    
00115             heater = 0;                                       
00116             status = 0;   
00117             wifly_on = 0;                                    
00118         }
00119         
00120         /*If the joystick is pushed upwards increase set temperature by 2
00121         And print the set temperature on LCD.*/
00122         if (temp_up.rising()) {                                
00123             temp = temp + 0x2;                                                      
00124         }
00125         
00126         /*else if the joystick is pushed downwards decrease set temperature by 2
00127         And print the set temperature on LCD.*/ 
00128         
00129         else if (temp_down.rising()) {                       
00130             temp = temp - 0x2;                                 
00131         }
00132 
00133         //Comparison logic and turn Heater ON/OFF
00134         if ((temp > (current.read()+ hys)) && thermostat == 1)
00135             heater =  1;
00136         else if ((temp < (current.read()- hys)) || thermostat == 0)
00137             heater = 0;
00138             
00139         if (acc_x_old != MMA.x() || acc_y_old != MMA.y() || acc_z_old != MMA.x())
00140        {
00141            no_move = 0;
00142        }
00143          
00144         Thread::wait(100);      //Temperature comparison will take place after 
00145                                       //every 100msec.
00146     }
00147 }
00148 /****************************************************************************************/
00149 
00150 
00151 /****************************************************************************************/
00152 /*Thread check movement: This thread detects if there is movement nearby the thermostat.*/
00153 /*If there is no movement this thread sets a variable called no_move which is furthur   */
00154 /*used to turn ON/OFF the system. Logic implemented for movement detection is as follows*/
00155 /*This thread is executed once every minute. Every time this thread is executed it      */
00156 /*compares the accelerometer reading with its previous value. If the reading is same    */
00157 /*(no movement detected) it increments a counter. When this counter reaches 20 (which   */
00158 /*means there is no movement for 20 mins) it sets the variable no_move to turn OFF the  */
00159 /*system. When a different accelerometer value is detected(movement present) it resets  */
00160 /*the variable which will in turn turn the system ON.                                   */
00161 /****************************************************************************************/
00162 void check_movement(void const *args)
00163 {
00164     static int move_cntr = 0;
00165     while (true) {
00166     acc_x_old = acc_x;
00167     acc_y_old = acc_y;
00168     acc_z_old = acc_z;
00169     acc_x = MMA.x();
00170     acc_y = MMA.y();
00171     acc_z = MMA.z();
00172     if (acc_x_old == acc_x && acc_y_old == acc_y && acc_z_old == acc_z)
00173     {
00174         move_cntr++;
00175         pc.printf("Value of move_cntr = %d\r\n",move_cntr);
00176         move = 011;
00177     }
00178     else {
00179         move_cntr = 0;
00180         pc.printf("Move_cntr reset\r\n");}
00181     if (move_cntr >= TIME)    //If the Accelerometer value remains constant for 20 mins no movement detected
00182         no_move = 1;
00183     else
00184         no_move = 0;
00185     Thread::wait(1*MIN);
00186     }
00187     
00188 }
00189 /****************************************************************************************/
00190 
00191 
00192 /****************************************************************************************/
00193 /*Thread main: This is the main thread which instantiates all other threads. The main   */
00194 /*thread also initializes the wifly module and communicates with the mbed via wifly.    */
00195 /*If the HTTP client is not connected, the main thread continues its operation through  */
00196 /*the on board joystick. Turning ON/OFF the thermostat remotely is not possible in such */
00197 /*a case. The other controls like the joystick and the accelorometer operate normally.  */
00198 /****************************************************************************************/
00199 int main() {
00200     
00201     Thread lcd_display(update_lcd,NULL,  osPriorityAboveNormal);
00202     Thread thermostat_thread(Thermostat_logic,NULL,  osPriorityAboveNormal);
00203     Thread accel_thread(check_movement,NULL,osPriorityAboveNormal);
00204     
00205     wifly.init(); //Use DHCP
00206     while (!wifly.connect());
00207     pc.printf("IP Address is %s\n\r", wifly.getIPAddress());
00208  
00209     TCPSocketServer server;
00210     
00211     server.bind(ECHO_SERVER_PORT);
00212     server.listen();
00213  
00214     printf("\nWait for new connection...\r\n");
00215     TCPSocketConnection client;
00216     server.accept(client);
00217     char buffer[3];   
00218     // NTPClient ntp;
00219     //ntp.setTime("nist1.symmetricom.com");
00220 
00221         while (true) {
00222             if (client.is_connected()){          
00223             int n = client.receive(buffer, sizeof(buffer));
00224             if (n <= 0)continue; 
00225             buffer[n] = 0;
00226             pc.printf("Buffer is %s\r\n",buffer);
00227             if (!(strcmp(buffer,"o")))
00228                wifly_on = 1;
00229             else if (!(strcmp(buffer,"f"))){
00230                wifly_on = 0;
00231                pc.printf("wifi off\r\n");
00232             }
00233                 Thread::wait(100);
00234         client.send_all(buffer,n);
00235         pc.printf("Sent data is %s\r\n",buffer);
00236         }
00237         else
00238         Thread::wait(1*SEC);
00239         Thread::wait(100);   //This wait is necessary for the condition in which http
00240                                      //client is connected but it does not receive anything.
00241                                      //if n<= 0
00242         }
00243 }
00244 /****************************************************************************************/