Diff: main.cpp

Revision:

0:44597d36d45c

Child:

1:39d8765b574d

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Tue Jan 05 17:16:36 2016 +0000
@@ -0,0 +1,52 @@
+/* 
+
+2645_Ticker
+
+Sample code from ELEC2645 Week 15 Lab
+
+Demonstrates how to use a ticker to generate a periodic timer interrupt
+
+(c) Craig A. Evans, University of Leeds, Jan 2016
+
+*/ 
+
+#include "mbed.h"
+
+// Create objects for ticker and red LED
+Ticker ticker;
+DigitalOut red_led(LED_RED);
+
+// flag - must be volatile as changes within ISR
+volatile int timer_flag = 0;
+
+// function prototypes
+void timer_isr();
+
+int main()
+{
+    // set-up the ticker so that the ISR it is called every 0.5 seconds
+    ticker.attach(&timer_isr,0.5);
+    // the on-board RGB LED is a common anode - writing a 1 to the pin will turn the LED OFF
+    red_led = 1;
+
+    while (1) {
+
+        // check if flag is set i.e. interrupt has occured
+        if (timer_flag) {
+            timer_flag = 0;  // if it has, clear the flag
+
+            // DO TASK HERE
+    
+        }
+
+        // put the MCU to sleep until an interrupt wakes it up
+        sleep();
+
+    }
+}
+
+// time-triggered interrupt
+void timer_isr()
+{
+    timer_flag = 1;   // set flag in ISR
+}