Diff: main.cpp

Revision:

0:4303da3c75bf

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Sun Jan 29 20:40:45 2017 +0000
@@ -0,0 +1,66 @@
+/**
+ * @brief first event control program with  MBED OS
+ */
+#include "mbed.h"
+#include "rtos.h"
+#include "mbed_events.h"
+
+/* declares threads for this demo: */
+const size_t a_stk_size = 1024;
+uint8_t a_stk[a_stk_size];
+Thread a_thread(osPriorityNormal, a_stk_size, &a_stk[0]);
+
+/* thread b is used as event loop thread*/
+Thread b_thread;
+
+/* queue used to handle events */
+EventQueue ev_queue(32 * EVENTS_EVENT_SIZE);
+
+/* reserve the debbuger uart to shell interface */
+Serial pc_serial(USBTX,USBRX);
+
+/* allocate HW for button with interrupt */
+InterruptIn sw(SW2);
+
+
+/**
+ * @brief thread a function 
+ */
+static void thread_a(void)
+{
+    int pressed = 0;
+    for(;;) {
+        /* halt thread until a signal is received */
+        a_thread.signal_wait(1, osWaitForever);
+        pressed++;
+        pc_serial.printf("## button press woke up this thread, noof presses: %d !##\n\r", pressed);
+        pc_serial.printf("## now this thread will wait for a new press !##\n\r");        
+    }
+}
+
+
+/**
+ * @brief event callback called from thread context 
+ */
+static void button_callback(void) 
+{
+    /* button callback is used to assert a signal, 
+     * this is the advantage of event loop, signals are not allowed
+     * to use in ISR, but this callback is executed from thread
+     * context
+     */
+     a_thread.signal_set(1);
+}
+
+
+/**
+ * @brief main application loop
+ */
+int main(void) 
+{  
+    pc_serial.baud(115200);
+    a_thread.start(thread_a);
+    b_thread.start(callback(&ev_queue, &EventQueue::dispatch_forever));
+    sw.rise(ev_queue.event(button_callback));
+    return 0;
+}
\ No newline at end of file