Diff: main.cpp

Revision:

0:39f5902e5782

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Mon Feb 27 22:34:26 2017 +0000
@@ -0,0 +1,87 @@
+#include "mbed.h"
+
+class Watchdog {
+public:
+//load timeout value and enable
+    void kick(float s) {
+        LPC_WDT->WDCLKSEL = 0x1; //Set CLK src to PCLK
+        uint32_t clk = SystemCoreClock / 16; //WD has /4 prescaler and PCLK default is /4
+        LPC_WDT->WDTC = s * (float)clk;
+        LPC_WDT->WDMOD = 0x3; //Enabled and Reset
+        kick();
+    }
+    //kick the dog by feeding required bit pattern
+    void kick() {
+        LPC_WDT->WDFEED = 0xAA;
+        LPC_WDT->WDFEED = 0x55;
+    }
+};
+
+DigitalOut myled2(p25);
+PwmOut myled3(p21);
+DigitalIn pb(p24);
+DigitalIn pwmup(p22);
+DigitalIn pwmdown(p23);
+Watchdog wdt;
+DigitalOut led1(LED1);
+DigitalOut led2(LED2);
+DigitalOut led3(LED3);
+DigitalOut led4(LED4);
+
+int main() {
+    // Part 1
+    pb.mode(PullUp); // The variable left_pb will be zero when the pushbutton for moving the player left is pressed
+    pwmup.mode(PullUp);
+    pwmdown.mode(PullUp);
+    
+    // Part 2
+    myled3.period(0.01f);
+    volatile float duty = 0.50f;
+    myled3.write(duty);
+    
+    // Watchdog
+    int count = 0;
+    // on reset indicate a watchdog reset on LED 4 or 3
+    if((LPC_WDT->WDMOD >> 2) & 1)
+        led4 = 1; else led3 = 1;
+    // set a 10 second timeout on WD timer hardware, longer than worst case main loop execution time
+    wdt.kick(5.0);
+    
+    // resets watchdog timer once every loop
+    while(1) {
+        //watchdog stuff, ldes 1 and 2 indicate normal operation
+        led1 = 1;
+        wait(0.05);
+        led1 = 0;
+        led2 = 1;
+        wait(0.05);
+        // Part 1
+        while(pb == 0) {
+            myled2 = 0;
+        }
+        myled2 = 1;
+        
+        // Part 2
+        if(pwmup == 0 && duty < 1.00f) {
+            //duty = duty + 0.001f;
+            duty += 0.05f;
+            //duty = 1.0f;
+            myled3.write(duty);
+            while(pwmup == 0) {}
+        }
+        if(pwmdown == 0 && duty > 0.00f) {
+            //duty = duty - 0.001f;
+            duty -= 0.05f;
+            //duty = 0.0f;
+            myled3.write(duty);
+            while(pwmdown == 0) {}
+        }
+        //watchdog fault simulation
+        if (count == 100) while (1) {};
+        // led 2 stays on during the fault
+        led2 = 0;
+        count++;
+        //end of main loop, kick the WD
+        wdt.kick();
+    }
+}