polling for lab2

Fork of digitalInPolling_sample by William Marsh

Revision:
2:cd1fe8c29793
Parent:
1:4709af498799
Child:
3:d35e20a7b695
--- a/main.cpp	Tue Jan 24 18:24:25 2017 +0000
+++ b/main.cpp	Tue Jan 16 18:02:44 2018 +0000
@@ -1,5 +1,4 @@
 #include "mbed.h"
-#include "rtos.h"
 
 // Labs 2: Example program for polling an input
 // --------------------------------------------
@@ -7,13 +6,12 @@
 //   - The thread monitors the position of the button
 //   - When the button transitions up and down, a press event is signaled 
 //   - Button bounce is guarded against
-// A second thread checks for the press event and toggles the LED
+// A second thread (the default one) checks for the press event and toggles the LED
 
-DigitalIn button(PTD0, PullUp);
-DigitalOut led(LED_RED);
+DigitalIn b1(PTD0, PullUp);
+DigitalOut led(LED1);
 
 Thread pollT ; // thread to poll
-Thread flashT ; // thread to flash light
 volatile int pressEvent = 0 ;  // Variabe set by the polling thread
 
 enum buttonPos { up, down, bounce }; // Button positions
@@ -23,19 +21,19 @@
     while (true) {
         switch (pos) {
             case up :
-                if (button == 0) {    // now down 
+                if (!b1.read()) {    // now down 
                     pressEvent = 1 ;  // transition occurred
                     pos = down ;
                 }
                 break ;
             case down : 
-                if (button == 1) { // no longer down
+                if (b1 == 1) { // no longer down
                     bcounter = 3 ; // wait four cycles
                     pos = bounce ;
                 }
                 break ;
             case bounce :
-                if (button == 0) { // down again - button has bounced
+                if (b1 == 0) { // down again - button has bounced
                     pos = down ;   // no event
                 } else if (bcounter == 0) {
                     pos = up ;     // delay passed - reset to up
@@ -48,8 +46,13 @@
     }
 }
 
-// Toggle the LED every time the button is pressed
-void flash() {
+/*  ---- Main function (default thread) ----
+    Note that if this thread completes, nothing else works
+ */
+int main() {
+    led = 1 ;  // Initially off
+    pollT.start(callback(polling));
+
     while(true) {
         if (pressEvent) {
             pressEvent = 0 ; // clear the event variable
@@ -57,9 +60,4 @@
         }
         Thread::wait(100) ;
     }
-}
-
-int main() {
-    pollT.start(&polling) ; // start the polling thread running 
-    flashT.start(&flash) ; // start the flashing thread running 
 }
\ No newline at end of file