main.cpp

00001 #include "mbed.h"
00002 #include "rtos.h"
00003 #include "wdt.h"
00004 
00005 // Sample program using the Watchdog
00006 // ---------------------------------
00007 //    * Three threads co-operate to flash two LEDs
00008 //    * A simple way to inject a fault, by pressing a button 
00009 //    * The watchdog is configured with a 32ms timeout
00010 
00011 #define ON 1
00012 #define OFF 0
00013 DigitalOut led_red(LED_RED, ON);
00014 DigitalIn button(PTD0, PullUp);
00015 DigitalOut led1(PTC12, OFF);
00016 DigitalOut led2(PTC13, OFF);
00017 Serial pc(USBTX, USBRX); 
00018 
00019 // This ticker is used to feed the watch dog
00020 Ticker tick;
00021 
00022 // Threads
00023 Thread threadT(osPriorityNormal,1000); // timer thread 
00024 Thread threadLED1(osPriorityNormal,1000); // thread LED1
00025 //Thread threadLED2(osPriorityNormal,1000); // thread LED2
00026 Thread threaddetection(osPriorityNormal,1000);
00027 
00028 //define the state of watch dog
00029 enum wState {Working, Stopped} ;
00030 wState watchdogflag;
00031 AnalogIn ainled1(A0); //LED1 ADC INPUT
00032 //AnalogIn ainled2(A1); //LED2 ADC INPUT
00033 float volt1,volt2;
00034 
00035 
00036 // ------------Fault Injection Button-------------
00037 //  Wait while the button is down
00038 //     Use this to simulate a STUCK fault
00039 // -----------------------------------------------
00040 void waitButton() {
00041    
00042     while (!button){
00043         pc.printf("stop watchdog");
00044         watchdogflag=Stopped;
00045         }
00046 }
00047 
00048 // ---Thread for controlling LED 1----------------
00049 //   Turn LED1 on/off in response to signals 
00050 // -----------------------------------------------
00051 void led1_thread() {  // method to run in thread
00052     osEvent evt ;
00053     while (true) {
00054         evt = Thread::signal_wait(0x0); // wait for any signal
00055         if (evt.status == osEventSignal) {
00056             if (evt.value.signals & 0x01) 
00057             {
00058                 led1 = ON ;
00059                 
00060             }
00061             if (evt.value.signals & 0x02) led1 = OFF ;
00062         } 
00063     }
00064 }
00065 
00066 // ---Thread for controlling LED 2----------------
00067 //   Turn LED2 on/off in response to signals 
00068 // -----------------------------------------------
00069 void led2_thread() {  // method to run in thread
00070     osEvent evt ;
00071     while (true) {
00072         evt = Thread::signal_wait(0x0); // wait for any signal
00073         if (evt.status == osEventSignal) {
00074             if (evt.value.signals & 0x01) 
00075             {
00076                led2 = ON ;       
00077             }
00078             if (evt.value.signals & 0x02) led2 = OFF ;
00079         } 
00080         // waitButton() ; // POSSIBLE FAULT HERE
00081     }
00082 }
00083 
00084 // ---Thread for timing --------------------------
00085 //   Send signals to the other threads
00086 // -----------------------------------------------
00087 void timer_thread() {  // method to run in thread
00088     while (true) {
00089         Thread::wait(250) ;
00090         threadLED1.signal_set(0x1) ;//on
00091  //       threadLED2.signal_set(0x1) ;//on
00092         Thread::wait(250) ;
00093         threadLED1.signal_set(0x2) ;//off
00094  //       threadLED2.signal_set(0x2) ;//off
00095         // waitButton() ; // POSSIBLE FAULT HERE
00096     }
00097 }
00098 
00099 void detection_thread() 
00100 { 
00101     int counter=0;
00102     while (1) 
00103     {
00104         volt1 = ainled1;
00105      //          pc.printf("%f\n\r",volt1);
00106         if (volt1>0.90) 
00107         {
00108             pc.printf("short circuit\n\r");
00109             led_red=0;
00110         }
00111         else
00112         {
00113            if(led1==1)
00114            {
00115                 if ((volt1<0.1))        
00116                 {    
00117                     counter++;
00118                     if (counter>5)
00119                     {
00120                          pc.printf("open circuit\n\r");
00121                         if(led_red==1)led_red=0;
00122                         counter =0;
00123                     }
00124                 }
00125                 else
00126                 {
00127                     pc.printf("%f\n\r",volt1);
00128                     if (led_red==0)led_red=1;
00129                 } 
00130             }
00131         }
00132  
00133        waitButton(); // POSSIBLE FAULT HERE     
00134     }     
00135 }
00136 
00137 // -----------MAIN-------------------------------
00138 //    Configure watchdog. Start threads. 
00139 //    Show start up with RED for 1sec
00140 //    Remember the watchdog is running
00141 //       - 1024ms to set it once
00142 //       - then must feed it every 32ms  
00143 // ----------------------------------------------
00144 
00145 void watchdog()
00146 {
00147     
00148     if (watchdogflag==Working)
00149         {
00150            wdt_kick_all(); 
00151         } 
00152 }
00153 
00154 
00155 int main(void) {
00156     
00157     wdt_32ms() ; // initialise watchdog - 32ms timeout
00158     watchdogflag = Working;
00159     tick.attach_us(callback(&watchdog), 20000); 
00160     
00161     // start threads
00162     threadT.start(&timer_thread) ; // start the timer thread 
00163     threadLED1.start(&led1_thread) ; // start the LED1 control thread 
00164     threaddetection.start(&detection_thread);
00165     
00166     // show start-up
00167     led_red = OFF;
00168     Thread::wait(1000) ;//1ms
00169     led_red = ON;
00170    
00171 }