Diff: main.cpp

Revision:

0:f0345f20337e

Child:

1:dc7c5869f9e1

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Tue Apr 02 17:24:04 2019 +0000
@@ -0,0 +1,60 @@
+#include "mbed.h"
+ 
+DigitalOut led1(LED1);
+DigitalOut led2(LED2);
+DigitalOut led3(LED3);
+
+DigitalOut red(p23);
+DigitalOut green(p24);
+DigitalOut blue(p25);
+ 
+class StopLight {
+private:
+    EventQueue _queue;
+    int _pending;
+ 
+    enum state { RED, GREEN, YELLOW };
+ 
+    // The _step function is a traditional FSM which enqueues transitions onto the event queue
+    void _step(state transition) {
+        switch (transition) {
+            case RED:
+                set_red();
+                _pending = _queue.call_in(1000, this, &StopLight::_step, GREEN);
+                break;
+ 
+            case GREEN:
+                set_green();
+                _pending = _queue.call_in(1000, this, &StopLight::_step, YELLOW);
+                break;
+ 
+            case YELLOW:
+                set_yellow();
+                _pending = _queue.call_in(500, this, &StopLight::_step, RED);
+                break;
+        }
+    }
+    void set_red(){
+        red = 0; green = 1; blue = 1;
+    }
+    void set_green(){
+        red = 1; green = 0; blue = 1;
+    }
+    void set_yellow() {
+        red = 0; green = 0; blue = 1;
+    }
+public:
+    // The fire function can immediately change states in the FSM
+    void fire() {
+        _queue.cancel(_pending);
+        _queue.call(this, &StopLight::_step, GREEN);
+        _queue.dispatch();
+    }
+};
+ 
+StopLight sl;
+ 
+int main (void) {
+    sl.fire();
+    wait(osWaitForever);
+}
\ No newline at end of file