Diff: main.cpp

Revision:

111:2b4b5da72a15

Parent:

110:a930767c281c

--- a/main.cpp	Fri Oct 01 03:05:20 2021 +0000
+++ b/main.cpp	Fri Oct 01 03:12:23 2021 +0000
@@ -1,43 +1,32 @@
 /*
-Project: 21_TimerTest2_v5
+Project: 21_WhatTime_v5
 File: main.cpp
  
-Tests timer peformance. Display new time difference with each button press
-and release. Differences of 4 or 5 microseconds are typical.
-
+Uses a timer to display the interval between button press and release.
+ 
+Created 12 Aug 2017 by Dr. Sheila Ross.
 Last modified 9/30/21 by C. S. Tritt (v. 1.0)
 */
 #include "mbed.h"
  
 // Construct a USER_BUTTON digital input.
 DigitalIn myButton(USER_BUTTON);
- 
 // Construct a timer object.
 Timer myTimer;
- 
 // Construct a transmit only serial connection over our USB.
 Serial pc(USBTX, NC, 9600);
- 
+
 int main()
 {
     myTimer.start();  // Start the timer.
- 
     while(true) { // Main loop.
-        if (myButton == 0) { // Button is pressed (active low).
-            // Save the time on timer.
-            int firstTime = myTimer.read_us();
-            int secondTime = myTimer.read_us();
-                     
+        if (myButton == 0) { // Button is pressed (its active low).
+            // Save the current timer value (state). uSs since reset.
+            float current_time = myTimer.read();            
             // Send the time as text via the serial port.
-            pc.printf("Time difference %i microseconds.\n", secondTime - 
-                firstTime );
-            
-             // Reset the timer.
-            myTimer.reset();
-                     
-            // Wait for the user to release the button.
-            while(myButton == 0) {
-            }
+            pc.printf("Time difference %f seconds.\n",current_time );         
+            myTimer.reset(); // Reset the timer.            
+            while(myButton == 0) {} // Empty loop. Wait for button release.
         }
     }
 }
\ No newline at end of file