Diff: main.cpp

Revision:

0:8fabd65058e2

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Thu Dec 10 13:29:01 2020 +0000
@@ -0,0 +1,53 @@
+/*
+
+2645_FSM_Counter
+
+Sample code from ELEC2645
+
+Demonstrates how to implement a simple FSM counter
+
+(c) Craig A. Evans, University of Leeds, Dec 2020
+
+*/
+#include "mbed.h"
+#include "platform/mbed_thread.h"   // for putting the thread to sleep
+
+// create a bus for writing to the output (LEDs) at once
+BusOut output(LED4,LED3,LED2,LED1);
+
+// array of states in the FSM, each element is the output of the counter
+// set the output in binary to make it easier, 0 is LED on, 1 is LED off
+int g_fsm[4] = {0b0001,0b0010,0b0100,0b1000};
+
+int main()
+{
+    int state = 0;
+
+    while(1) {  // loop forever
+
+        output = g_fsm[state];  // output current state
+
+        // check which state we are in and see which the next state should be
+        switch(state) {
+            case 0:
+                state = 1;
+                break;
+            case 1:
+                state = 2;
+                break;
+            case 2:
+                state = 3;
+                break;
+            case 3:
+                state = 0;
+                break;
+            default:
+                error("Invalid state");
+                state = 0; //invalid state - call error routine
+                // and jump to starting state i.e. state = 0
+                break;
+        }
+
+        thread_sleep_for(500);  // 500 ms delay
+    }
+}