Haozun Sun / Mbed OS ADC_HaozunSun_180773877

ADC

main.cpp@6:ef4c3d706a30, 2020-02-27 (annotated)

Committer:
hzsun
Date:
Thu Feb 27 19:57:56 2020 +0000
Revision:
6:ef4c3d706a30
Parent:
4:ebd00f94455a 
180773877 Haozun Sun

Who changed what in which revision?

UserRevisionLine numberNew contents of line
WilliamMarshQMUL 0:ad3cdc525b99 1
WilliamMarshQMUL 0:ad3cdc525b99 2
WilliamMarshQMUL 0:ad3cdc525b99 3 #include "mbed.h"
WilliamMarshQMUL 1:126dd2f5fc2d 4
hzsun 6:ef4c3d706a30 5 InterruptIn button(PTD0); //buttton function
WilliamMarshQMUL 0:ad3cdc525b99 6 AnalogIn ain(A0) ; // Analog input
WilliamMarshQMUL 4:ebd00f94455a 7 EventQueue queue; // creates an event queue, to call read ADC
WilliamMarshQMUL 0:ad3cdc525b99 8
hzsun 6:ef4c3d706a30 9 DigitalOut firstLED(D3); // 1st lED
hzsun 6:ef4c3d706a30 10 DigitalOut secondLED(D4); // 2nd lED
hzsun 6:ef4c3d706a30 11 DigitalOut thirdLED(D5); // 3rd lED
hzsun 6:ef4c3d706a30 12 DigitalOut fourthLED(D6); // 4th lED
hzsun 6:ef4c3d706a30 13 DigitalOut fifthLED(D7); // 5th lED
hzsun 6:ef4c3d706a30 14
WilliamMarshQMUL 0:ad3cdc525b99 15 Serial pc(USBTX, USBRX); // tx, rx, for debugging
WilliamMarshQMUL 0:ad3cdc525b99 16
WilliamMarshQMUL 4:ebd00f94455a 17 // This thread runs the event queue
WilliamMarshQMUL 4:ebd00f94455a 18 Thread eventThread ;
WilliamMarshQMUL 3:f5d7fddeef39 19
WilliamMarshQMUL 0:ad3cdc525b99 20 // Message type
WilliamMarshQMUL 0:ad3cdc525b99 21 typedef struct {
WilliamMarshQMUL 0:ad3cdc525b99 22 uint16_t analog; /* Analog input value */
WilliamMarshQMUL 0:ad3cdc525b99 23 } message_t;
WilliamMarshQMUL 0:ad3cdc525b99 24
WilliamMarshQMUL 0:ad3cdc525b99 25 // Mail box
WilliamMarshQMUL 0:ad3cdc525b99 26 Mail<message_t, 2> mailbox;
WilliamMarshQMUL 0:ad3cdc525b99 27
WilliamMarshQMUL 0:ad3cdc525b99 28 // Function called every 10ms to read ADC
WilliamMarshQMUL 4:ebd00f94455a 29 // Average using a low pass filter
WilliamMarshQMUL 0:ad3cdc525b99 30 // Every 10th value is sent to mailbox
WilliamMarshQMUL 4:ebd00f94455a 31 volatile int samples = 0 ;
WilliamMarshQMUL 4:ebd00f94455a 32 volatile uint16_t smoothed = 0 ;
WilliamMarshQMUL 4:ebd00f94455a 33
hzsun 6:ef4c3d706a30 34 volatile int pressEvent = 0 ; //pressEvent as comunication flag
hzsun 6:ef4c3d706a30 35 void buttonCallback(){ //button call back function
hzsun 6:ef4c3d706a30 36 pressEvent=!pressEvent;
hzsun 6:ef4c3d706a30 37 }
hzsun 6:ef4c3d706a30 38
hzsun 6:ef4c3d706a30 39
WilliamMarshQMUL 0:ad3cdc525b99 40 void readA0() {
WilliamMarshQMUL 4:ebd00f94455a 41 smoothed = (smoothed >> 1) + (ain.read_u16() >> 1) ;
WilliamMarshQMUL 4:ebd00f94455a 42 samples++ ;
WilliamMarshQMUL 4:ebd00f94455a 43 if (samples == 10) {
WilliamMarshQMUL 4:ebd00f94455a 44 // send to thread
WilliamMarshQMUL 4:ebd00f94455a 45 message_t *mess = mailbox.alloc() ; // may fail but does not block
WilliamMarshQMUL 4:ebd00f94455a 46 if (mess) {
WilliamMarshQMUL 4:ebd00f94455a 47 mess->analog = smoothed ;
WilliamMarshQMUL 4:ebd00f94455a 48 mailbox.put(mess); // fails but does not block if full
WilliamMarshQMUL 0:ad3cdc525b99 49 }
WilliamMarshQMUL 4:ebd00f94455a 50 samples = 0;
WilliamMarshQMUL 4:ebd00f94455a 51 }
WilliamMarshQMUL 0:ad3cdc525b99 52 }
WilliamMarshQMUL 0:ad3cdc525b99 53
WilliamMarshQMUL 0:ad3cdc525b99 54 // Write voltage digits
WilliamMarshQMUL 0:ad3cdc525b99 55 // v Voltage as scale int, e.g. 3.30 is 330
WilliamMarshQMUL 0:ad3cdc525b99 56 void vToString(int v, char* s) {
WilliamMarshQMUL 0:ad3cdc525b99 57 s[3] = '0' + (v % 10) ;
WilliamMarshQMUL 0:ad3cdc525b99 58 v = v / 10 ;
WilliamMarshQMUL 0:ad3cdc525b99 59 s[2] = '0' + (v % 10) ;
WilliamMarshQMUL 0:ad3cdc525b99 60 v = v / 10 ;
WilliamMarshQMUL 0:ad3cdc525b99 61 s[0] = '0' + (v % 10) ;
WilliamMarshQMUL 0:ad3cdc525b99 62 }
WilliamMarshQMUL 0:ad3cdc525b99 63
WilliamMarshQMUL 0:ad3cdc525b99 64 // Main program
WilliamMarshQMUL 0:ad3cdc525b99 65 // Initialise variables
WilliamMarshQMUL 0:ad3cdc525b99 66 // Attach ISR for ticker
WilliamMarshQMUL 0:ad3cdc525b99 67 // Procss messages from mailbox
WilliamMarshQMUL 0:ad3cdc525b99 68 int main() {
hzsun 6:ef4c3d706a30 69
hzsun 6:ef4c3d706a30 70
WilliamMarshQMUL 0:ad3cdc525b99 71 int counter = 0 ;
WilliamMarshQMUL 0:ad3cdc525b99 72 char vstring[] = "X.XX\r\n" ;
hzsun 6:ef4c3d706a30 73 firstLED=0; // 1st lED
hzsun 6:ef4c3d706a30 74 secondLED=0; // 2nd lED
hzsun 6:ef4c3d706a30 75 thirdLED=0; // 3rd lED
hzsun 6:ef4c3d706a30 76 fourthLED=0; // 4th lED
hzsun 6:ef4c3d706a30 77 fifthLED=0; // 5th LED
hzsun 6:ef4c3d706a30 78
hzsun 6:ef4c3d706a30 79 int volts=0;
hzsun 6:ef4c3d706a30 80 int MaxVolt =330;
WilliamMarshQMUL 3:f5d7fddeef39 81
WilliamMarshQMUL 4:ebd00f94455a 82 // Start the event queue
WilliamMarshQMUL 4:ebd00f94455a 83 eventThread.start(callback(&queue, &EventQueue::dispatch_forever));
hzsun 6:ef4c3d706a30 84 button.mode(PullUp);
hzsun 6:ef4c3d706a30 85 button.fall(&buttonCallback);
WilliamMarshQMUL 4:ebd00f94455a 86 // call the readA0 function every 10ms
WilliamMarshQMUL 4:ebd00f94455a 87 queue.call_every(10, readA0) ;
WilliamMarshQMUL 0:ad3cdc525b99 88
hzsun 6:ef4c3d706a30 89
WilliamMarshQMUL 0:ad3cdc525b99 90 while (true) {
hzsun 6:ef4c3d706a30 91 osEvent evt = mailbox.get(); // wait for mail
hzsun 6:ef4c3d706a30 92
hzsun 6:ef4c3d706a30 93 if (evt.status == osEventMail) {
WilliamMarshQMUL 0:ad3cdc525b99 94 message_t* mess = (message_t*)evt.value.p ;
WilliamMarshQMUL 0:ad3cdc525b99 95 volts = (mess->analog * 330) / 0xffff ;
hzsun 6:ef4c3d706a30 96 if(pressEvent) { //when button is pressed
hzsun 6:ef4c3d706a30 97 MaxVolt=volts ; // get the present value as the max voltage
hzsun 6:ef4c3d706a30 98 pressEvent =0; //set the button to up position
hzsun 6:ef4c3d706a30 99 }
hzsun 6:ef4c3d706a30 100 mailbox.free (mess);
hzsun 6:ef4c3d706a30 101
hzsun 6:ef4c3d706a30 102
hzsun 6:ef4c3d706a30 103 if (volts==0) {
hzsun 6:ef4c3d706a30 104 firstLED=0; // 1st lED
hzsun 6:ef4c3d706a30 105 secondLED=0; // 2nd lED
hzsun 6:ef4c3d706a30 106 thirdLED=0; // 3rd lED
hzsun 6:ef4c3d706a30 107 fourthLED=0; // 4th lED
hzsun 6:ef4c3d706a30 108 fifthLED=0; // 5th LED
hzsun 6:ef4c3d706a30 109 }
hzsun 6:ef4c3d706a30 110
hzsun 6:ef4c3d706a30 111 if (volts>MaxVolt/6) { //when voltage is bigger than 1/6 of the max volatge
hzsun 6:ef4c3d706a30 112 firstLED=1;
hzsun 6:ef4c3d706a30 113 secondLED=0;
hzsun 6:ef4c3d706a30 114 thirdLED=0;
hzsun 6:ef4c3d706a30 115 fourthLED=0;
hzsun 6:ef4c3d706a30 116 fifthLED=0;
WilliamMarshQMUL 0:ad3cdc525b99 117 }
hzsun 6:ef4c3d706a30 118
hzsun 6:ef4c3d706a30 119 if (volts>2*MaxVolt/6) { //when voltage is bigger than 2/6 of the max volatge
hzsun 6:ef4c3d706a30 120 secondLED=1;
hzsun 6:ef4c3d706a30 121 thirdLED=0;
hzsun 6:ef4c3d706a30 122 fourthLED=0;
hzsun 6:ef4c3d706a30 123 fifthLED=0;
hzsun 6:ef4c3d706a30 124 }
hzsun 6:ef4c3d706a30 125
hzsun 6:ef4c3d706a30 126 if (volts>3*MaxVolt/6) { //when voltage is bigger than 3/6 of the max volatge
hzsun 6:ef4c3d706a30 127 thirdLED=1;
hzsun 6:ef4c3d706a30 128 fourthLED=0;
hzsun 6:ef4c3d706a30 129 fifthLED=0;
hzsun 6:ef4c3d706a30 130 }
hzsun 6:ef4c3d706a30 131
hzsun 6:ef4c3d706a30 132 if (volts>4*MaxVolt/6) { //when voltage is bigger than 4/6 of the max volatge
hzsun 6:ef4c3d706a30 133 fourthLED=1;
hzsun 6:ef4c3d706a30 134 fifthLED=0;
hzsun 6:ef4c3d706a30 135 }
hzsun 6:ef4c3d706a30 136
hzsun 6:ef4c3d706a30 137 if (volts>5*MaxVolt/6) { //when voltage is bigger than 5/6 of the max volatge
hzsun 6:ef4c3d706a30 138 fifthLED=1;
hzsun 6:ef4c3d706a30 139 }
hzsun 6:ef4c3d706a30 140 vToString(volts, vstring) ; // function to show the value on the computer
hzsun 6:ef4c3d706a30 141 counter++;
hzsun 6:ef4c3d706a30 142 if (counter==10) {
hzsun 6:ef4c3d706a30 143 pc.printf(vstring);
hzsun 6:ef4c3d706a30 144 counter=0;
hzsun 6:ef4c3d706a30 145 }
hzsun 6:ef4c3d706a30 146
WilliamMarshQMUL 0:ad3cdc525b99 147 }
WilliamMarshQMUL 0:ad3cdc525b99 148 }
WilliamMarshQMUL 0:ad3cdc525b99 149 }
hzsun 6:ef4c3d706a30 150