Revision 6:ef4c3d706a30, committed 2020-02-27

Comitter:

hzsun

Date:

Thu Feb 27 19:57:56 2020 +0000

Parent:

5:1f36332ed463

Commit message:

180773877 Haozun Sun

Changed in this revision

--- a/main.cpp	Thu Feb 06 08:11:53 2020 +0000
+++ b/main.cpp	Thu Feb 27 19:57:56 2020 +0000
@@ -1,15 +1,17 @@
 
-// LAB 3 SAMPLE PROGRAM 1
-//   Revised for mbed 5 
-//   Revised to replace Ticker with event queue and thread
 
 #include "mbed.h"
 
-
+InterruptIn button(PTD0);    //buttton function
 AnalogIn ain(A0) ;          // Analog input
-DigitalOut led1(LED_RED);   // Red LED
 EventQueue queue;  // creates an event queue, to call read ADC
 
+DigitalOut firstLED(D3);   // 1st lED
+DigitalOut secondLED(D4);   // 2nd lED
+DigitalOut thirdLED(D5);   // 3rd lED
+DigitalOut fourthLED(D6);   // 4th lED
+DigitalOut fifthLED(D7);   // 5th lED
+
 Serial pc(USBTX, USBRX); // tx, rx, for debugging
 
 // This thread runs the event queue
@@ -29,6 +31,12 @@
 volatile int samples = 0 ;
 volatile uint16_t smoothed = 0 ; 
 
+volatile int pressEvent = 0 ;         //pressEvent as comunication flag 
+void buttonCallback(){                //button call back function 
+    pressEvent=!pressEvent;            
+    }
+    
+
 void readA0() {
     smoothed = (smoothed >> 1) + (ain.read_u16() >> 1) ;
     samples++ ;
@@ -58,31 +66,85 @@
 //   Attach ISR for ticker
 //   Procss messages from mailbox    
 int main() {
-    led1 = 1 ; // turn off 
-    int volts = 0 ;
-    const int threshold = 100 ;
+
+
     int counter = 0 ;
     char vstring[] = "X.XX\r\n" ;
+    firstLED=0;   // 1st lED
+    secondLED=0;   // 2nd lED
+    thirdLED=0;   // 3rd lED
+    fourthLED=0;   // 4th lED
+    fifthLED=0;    // 5th LED
+    
+    int volts=0;
+    int MaxVolt =330;
     
     // Start the event queue
     eventThread.start(callback(&queue, &EventQueue::dispatch_forever));
-
+    button.mode(PullUp);
+    button.fall(&buttonCallback); 
     // call the readA0 function every 10ms 
     queue.call_every(10, readA0) ; 
 
+
     while (true) {
-        osEvent evt = mailbox.get(); // wait for mail 
-        if (evt.status == osEventMail) {
+        osEvent evt = mailbox.get(); // wait for mail
+
+        if (evt.status == osEventMail) {  
             message_t* mess = (message_t*)evt.value.p ;
             volts = (mess->analog * 330) / 0xffff ;
-            mailbox.free(mess) ;  // free the message space
-            if (volts > threshold) led1 = 0 ; else led1 = 1 ;
-            vToString(volts, vstring) ;
-            counter++ ;
-            if (counter == 10) {  // limit bandwidth of serial
-                pc.printf(vstring) ;
-                counter = 0 ;
+            if(pressEvent) {         //when button is pressed 
+                MaxVolt=volts ;     // get the present value as the max voltage 
+                pressEvent =0;      //set the button to up position 
+            }
+            mailbox.free (mess);
+
+
+            if (volts==0) {
+                firstLED=0;   // 1st lED
+                secondLED=0;   // 2nd lED
+                thirdLED=0;   // 3rd lED
+                fourthLED=0;   // 4th lED
+                fifthLED=0;    // 5th LED
+            }
+
+            if (volts>MaxVolt/6) {        //when voltage is bigger than 1/6 of the max volatge
+                firstLED=1;
+                secondLED=0;
+                thirdLED=0;
+                fourthLED=0;
+                fifthLED=0;
             }
+
+            if (volts>2*MaxVolt/6) {       //when voltage is bigger than 2/6 of the max volatge
+                secondLED=1;
+                thirdLED=0;
+                fourthLED=0;
+                fifthLED=0;
+            }
+
+            if (volts>3*MaxVolt/6) {     //when voltage is bigger than 3/6 of the max volatge
+                thirdLED=1;
+                fourthLED=0;
+                fifthLED=0;
+            }
+
+            if (volts>4*MaxVolt/6) {   //when voltage is bigger than 4/6 of the max volatge
+                fourthLED=1;
+                fifthLED=0;
+            }
+
+            if (volts>5*MaxVolt/6) {    //when voltage is bigger than 5/6 of the max volatge
+                fifthLED=1;
+            } 
+            vToString(volts, vstring) ;      // function to show the value on the computer
+            counter++;
+            if (counter==10) {
+                pc.printf(vstring);
+                counter=0;
+            }
+
         }
     }
 }
+