Revision 4:c8b84240732a, committed 2018-02-01

Comitter:

natgovor

Date:

Thu Feb 01 12:30:18 2018 +0000

Parent:

3:05b6a1431a6b

Commit message:

Implemented interrupt code to handle presses of two buttons and control 2 leds separately.

Changed in this revision

diff -r 05b6a1431a6b -r c8b84240732a main.cpp
--- a/main.cpp	Tue Jan 16 18:14:21 2018 +0000
+++ b/main.cpp	Thu Feb 01 12:30:18 2018 +0000
@@ -6,31 +6,71 @@
 //    is pressed
 // The callback uses a shared variable to signal another thread
 
-InterruptIn button(PTD0);
-DigitalOut led(LED_GREEN);
+InterruptIn redButton(PTD0);
+InterruptIn blueButton(PTD5);
+DigitalOut redLed(LED_RED);
+DigitalOut blueLed(LED_BLUE);
 
-volatile int pressEvent = 0 ;
+volatile int redPressEvent = 0;
+volatile int bluePressEvent = 0;
 
 // This function is invoked when then interrupt occurs
 //   Signal that the button has been pressed
 //   Note: bounce may occur 
-void buttonCallback(){
-    pressEvent = 1 ;
+void redButtonCallback(){
+    redPressEvent = 1 ;
+}
+
+void blueButtonCallback(){
+    bluePressEvent = 1 ;
 }
 
 /*  ---- Main function (default thread) ----
     Note that if this thread completes, nothing else works
  */
 int main() {
-    button.mode(PullUp);             // Ensure button i/p has pull up
-    button.fall(&buttonCallback) ;   // Attach function to falling edge
+    // LEDa are on by default
+    redLed = 0;
+    blueLed = 0;
+    
+    int flashPeriod = 5;
+    int redBtnCounter = flashPeriod;
+    int blueBtnCounter = flashPeriod;
+    
+    bool redIsFlashing = true;
+    bool blueIsFlashing = true;
+    
+    redButton.mode(PullUp);             // Ensure button i/p has pull up
+    redButton.fall(&redButtonCallback) ;   // Attach function to falling edge
+    blueButton.mode(PullUp);             // Ensure button i/p has pull up
+    blueButton.fall(&blueButtonCallback) ;   // Attach function to falling edge   
 
     while(true) {
-        // Toggle the LED every time the button is pressed
-        if (pressEvent) {
-            led = !led ;
-            pressEvent = 0 ; // Clear the event variable
+        Thread::wait(100);
+        if (redIsFlashing) {
+            redBtnCounter--;
+        }
+        if (blueIsFlashing) {
+            blueBtnCounter--;
+        }
+        
+        if (redBtnCounter == 0) {
+            redLed = !redLed;
+            redBtnCounter = flashPeriod;
         }
-        Thread::wait(100) ;
+        if (blueBtnCounter == 0) {
+            blueLed = !blueLed;
+            blueBtnCounter = flashPeriod;
+        }
+        
+        // Stop flashing (freeze in the current state) every time the button is pressed
+        if (redPressEvent) {
+            redIsFlashing = !redIsFlashing;
+            redPressEvent = 0; // Clear the event variable
+        }
+        if (bluePressEvent) {
+            blueIsFlashing = !blueIsFlashing;
+            bluePressEvent = 0; // Clear the event variable
+        }
     }
 }
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