Diff: main.cpp

Revision:

2:ca251bdda621

Parent:

1:e84a51c98d75

Child:

3:a39db8aa11e8

--- a/main.cpp	Mon Oct 23 09:47:16 2017 +0000
+++ b/main.cpp	Mon Oct 23 12:25:13 2017 +0000
@@ -1,13 +1,12 @@
 #include "mbed.h"
-#include "SWPoll.hpp"
 
 #define N 1000000
 #define RELEASED 0
 #define PRESSED  1
 
 //Function prototypes
-void task1();
-void task2();
+void blockOnSwitch1();
+void blockOnSwitch2();
 
 //Hardware objects
 DigitalOut red_led(PE_15);     //CountUp is in its critical section
@@ -19,29 +18,58 @@
 DigitalIn sw1(PE_12);
 DigitalIn sw2(PE_14);
 
-SWPoll switch1(sw1, red_led);
-SWPoll switch2(sw2, green_led);
-
-//LOOK AT SWPoll.hpp for the definition of the SWPoll class
-
+//The code below is hugely flawed and is only to
+//illustrate the problem of blocking hardware
 int main() {
     
-    //Main uses a Timer
+    //Light up
+    red_led    = 1;
     yellow_led = 1;
-    Timer t;
-        
+    green_led  = 1;
+    onboardLED = 1;
+    
     //Now loop forever
-    t.start();
     while(1) { 
-        //Flash the yellow on the "main thread"
-        if (t.read_ms() >= 500) {
-            yellow_led = !yellow_led;   
-            t.reset(); 
-        }
-        switch1.poll();
-        switch2.poll();
         
+        //Wait for user to press and release sw1
+        blockOnSwitch1();
+
+        //Wait for user to press and release sw2
+        blockOnSwitch2();
+
+        //Flash the yellow
+        yellow_led = !yellow_led;
+        wait(0.5);
     };
 }
 
 
+//Thread 1  - polling sw1 and controlling the red LED
+void blockOnSwitch1()
+{
+    //Spin on sw1
+    while (sw1 == RELEASED) {};
+    //Allow short delay for switch bounce
+    wait(0.2);
+    //Spin again on sw1
+    while (sw1 == PRESSED) {};    
+    //Toggle LED
+    red_led = !red_led;
+    //Again, wait for switch bounce
+    wait(0.2);
+}
+
+//Thread 2  - polling sw2 and controlling the green LED
+void blockOnSwitch2()
+{
+    //Spin on sw2
+    while (sw2 == RELEASED) {};
+    //Allow short delay for switch bounce
+    wait(0.2);
+    //Spin again on sw2
+    while (sw2 == PRESSED) {};    
+    //Toggle LED
+    green_led = !green_led;
+    //Again, wait for switch bounce
+    wait(0.2);  
+}