Akhil Nair / Mbed OS Lab3p1

Lab 3 the ADC part with the leds

main.cpp@5:beff003ed7e0, 2019-02-07 (annotated)

Committer:
anair12345
Date:
Thu Feb 07 13:43:32 2019 +0000
Revision:
5:beff003ed7e0
Parent:
4:ebd00f94455a 
lab 3 part 1 full

Who changed what in which revision?

UserRevisionLine numberNew contents of line
WilliamMarshQMUL 0:ad3cdc525b99 1 // LAB 3 SAMPLE PROGRAM 1
WilliamMarshQMUL 3:f5d7fddeef39 2 // Revised for mbed 5
WilliamMarshQMUL 4:ebd00f94455a 3 // Revised to replace Ticker with event queue and thread
WilliamMarshQMUL 0:ad3cdc525b99 4
WilliamMarshQMUL 0:ad3cdc525b99 5 #include "mbed.h"
WilliamMarshQMUL 1:126dd2f5fc2d 6
anair12345 5:beff003ed7e0 7 AnalogIn ain(A0) ; // Analog input
WilliamMarshQMUL 0:ad3cdc525b99 8
anair12345 5:beff003ed7e0 9 DigitalOut led0(PTA13);
anair12345 5:beff003ed7e0 10 DigitalOut led1(PTD5);
anair12345 5:beff003ed7e0 11 DigitalOut led2(PTD0);
anair12345 5:beff003ed7e0 12 DigitalOut led3(PTD2);
anair12345 5:beff003ed7e0 13 DigitalOut led4(PTD3);
anair12345 5:beff003ed7e0 14
anair12345 5:beff003ed7e0 15 DigitalIn b1(PTA1, PullUp);
anair12345 5:beff003ed7e0 16
anair12345 5:beff003ed7e0 17 //DigitalOut led1(REDLED); // Red LED
WilliamMarshQMUL 4:ebd00f94455a 18 EventQueue queue; // creates an event queue, to call read ADC
WilliamMarshQMUL 0:ad3cdc525b99 19
WilliamMarshQMUL 0:ad3cdc525b99 20 Serial pc(USBTX, USBRX); // tx, rx, for debugging
WilliamMarshQMUL 0:ad3cdc525b99 21
WilliamMarshQMUL 4:ebd00f94455a 22 // This thread runs the event queue
WilliamMarshQMUL 4:ebd00f94455a 23 Thread eventThread ;
WilliamMarshQMUL 3:f5d7fddeef39 24
WilliamMarshQMUL 0:ad3cdc525b99 25 // Message type
WilliamMarshQMUL 0:ad3cdc525b99 26 typedef struct {
WilliamMarshQMUL 0:ad3cdc525b99 27 uint16_t analog; /* Analog input value */
anair12345 5:beff003ed7e0 28 int button;
WilliamMarshQMUL 0:ad3cdc525b99 29 } message_t;
WilliamMarshQMUL 0:ad3cdc525b99 30
WilliamMarshQMUL 0:ad3cdc525b99 31 // Mail box
WilliamMarshQMUL 0:ad3cdc525b99 32 Mail<message_t, 2> mailbox;
WilliamMarshQMUL 0:ad3cdc525b99 33
WilliamMarshQMUL 0:ad3cdc525b99 34 // Function called every 10ms to read ADC
WilliamMarshQMUL 4:ebd00f94455a 35 // Average using a low pass filter
WilliamMarshQMUL 0:ad3cdc525b99 36 // Every 10th value is sent to mailbox
WilliamMarshQMUL 4:ebd00f94455a 37 volatile int samples = 0 ;
WilliamMarshQMUL 4:ebd00f94455a 38 volatile uint16_t smoothed = 0 ;
WilliamMarshQMUL 4:ebd00f94455a 39
anair12345 5:beff003ed7e0 40 //Thread pollT ;
anair12345 5:beff003ed7e0 41 volatile int pressEvent = 0 ;
anair12345 5:beff003ed7e0 42
anair12345 5:beff003ed7e0 43 enum buttonPos { up, down, bounce }; // Button positions
anair12345 5:beff003ed7e0 44
anair12345 5:beff003ed7e0 45 buttonPos pos = up ;
anair12345 5:beff003ed7e0 46 int bcounter = 0 ;
anair12345 5:beff003ed7e0 47
anair12345 5:beff003ed7e0 48 void readA0() {
WilliamMarshQMUL 4:ebd00f94455a 49 smoothed = (smoothed >> 1) + (ain.read_u16() >> 1) ;
WilliamMarshQMUL 4:ebd00f94455a 50 samples++ ;
anair12345 5:beff003ed7e0 51
anair12345 5:beff003ed7e0 52 switch (pos) {
anair12345 5:beff003ed7e0 53 case up :
anair12345 5:beff003ed7e0 54 if (!b1.read()) { // now down
anair12345 5:beff003ed7e0 55 pressEvent = 1 ; // transition occurred
anair12345 5:beff003ed7e0 56 pos = down ;
anair12345 5:beff003ed7e0 57 }
anair12345 5:beff003ed7e0 58 break ;
anair12345 5:beff003ed7e0 59 case down :
anair12345 5:beff003ed7e0 60 if (b1 == 1) { // no longer down
anair12345 5:beff003ed7e0 61 bcounter = 3 ; // wait four cycles
anair12345 5:beff003ed7e0 62 pos = bounce ;
anair12345 5:beff003ed7e0 63 }
anair12345 5:beff003ed7e0 64 break ;
anair12345 5:beff003ed7e0 65 case bounce :
anair12345 5:beff003ed7e0 66 if (b1 == 0) { // down again - button has bounced
anair12345 5:beff003ed7e0 67 pos = down ; // no event
anair12345 5:beff003ed7e0 68 } else if (bcounter == 0) {
anair12345 5:beff003ed7e0 69 pos = up ; // delay passed - reset to up
anair12345 5:beff003ed7e0 70 } else {
anair12345 5:beff003ed7e0 71 bcounter-- ; // continue waiting
anair12345 5:beff003ed7e0 72 }
anair12345 5:beff003ed7e0 73 break ;
anair12345 5:beff003ed7e0 74 }
anair12345 5:beff003ed7e0 75 wait(0.03);
anair12345 5:beff003ed7e0 76
WilliamMarshQMUL 4:ebd00f94455a 77 if (samples == 10) {
WilliamMarshQMUL 4:ebd00f94455a 78 // send to thread
WilliamMarshQMUL 4:ebd00f94455a 79 message_t *mess = mailbox.alloc() ; // may fail but does not block
WilliamMarshQMUL 4:ebd00f94455a 80 if (mess) {
WilliamMarshQMUL 4:ebd00f94455a 81 mess->analog = smoothed ;
anair12345 5:beff003ed7e0 82 mess->button = pressEvent ;
WilliamMarshQMUL 4:ebd00f94455a 83 mailbox.put(mess); // fails but does not block if full
anair12345 5:beff003ed7e0 84 pressEvent = 0;// clear press
WilliamMarshQMUL 0:ad3cdc525b99 85 }
WilliamMarshQMUL 4:ebd00f94455a 86 samples = 0;
anair12345 5:beff003ed7e0 87
WilliamMarshQMUL 4:ebd00f94455a 88 }
WilliamMarshQMUL 0:ad3cdc525b99 89 }
WilliamMarshQMUL 0:ad3cdc525b99 90
WilliamMarshQMUL 0:ad3cdc525b99 91 // Write voltage digits
WilliamMarshQMUL 0:ad3cdc525b99 92 // v Voltage as scale int, e.g. 3.30 is 330
WilliamMarshQMUL 0:ad3cdc525b99 93 void vToString(int v, char* s) {
WilliamMarshQMUL 0:ad3cdc525b99 94 s[3] = '0' + (v % 10) ;
WilliamMarshQMUL 0:ad3cdc525b99 95 v = v / 10 ;
WilliamMarshQMUL 0:ad3cdc525b99 96 s[2] = '0' + (v % 10) ;
WilliamMarshQMUL 0:ad3cdc525b99 97 v = v / 10 ;
WilliamMarshQMUL 0:ad3cdc525b99 98 s[0] = '0' + (v % 10) ;
WilliamMarshQMUL 0:ad3cdc525b99 99 }
WilliamMarshQMUL 0:ad3cdc525b99 100
WilliamMarshQMUL 0:ad3cdc525b99 101 // Main program
WilliamMarshQMUL 0:ad3cdc525b99 102 // Initialise variables
WilliamMarshQMUL 0:ad3cdc525b99 103 // Attach ISR for ticker
WilliamMarshQMUL 0:ad3cdc525b99 104 // Procss messages from mailbox
WilliamMarshQMUL 0:ad3cdc525b99 105 int main() {
anair12345 5:beff003ed7e0 106 led0 = 0 ; // turn off
anair12345 5:beff003ed7e0 107 led1 = 0 ;
anair12345 5:beff003ed7e0 108 led2 = 0 ;
anair12345 5:beff003ed7e0 109 led3 = 0 ;
anair12345 5:beff003ed7e0 110 led4 = 0 ;
anair12345 5:beff003ed7e0 111
WilliamMarshQMUL 0:ad3cdc525b99 112 int volts = 0 ;
anair12345 5:beff003ed7e0 113 int threshold[] = {55,110,165,220,275,330} ;
WilliamMarshQMUL 0:ad3cdc525b99 114 int counter = 0 ;
WilliamMarshQMUL 0:ad3cdc525b99 115 char vstring[] = "X.XX\r\n" ;
WilliamMarshQMUL 3:f5d7fddeef39 116
anair12345 5:beff003ed7e0 117 //pollT.start(callback(polling));
anair12345 5:beff003ed7e0 118
WilliamMarshQMUL 4:ebd00f94455a 119 // Start the event queue
WilliamMarshQMUL 4:ebd00f94455a 120 eventThread.start(callback(&queue, &EventQueue::dispatch_forever));
WilliamMarshQMUL 4:ebd00f94455a 121
WilliamMarshQMUL 4:ebd00f94455a 122 // call the readA0 function every 10ms
WilliamMarshQMUL 4:ebd00f94455a 123 queue.call_every(10, readA0) ;
WilliamMarshQMUL 0:ad3cdc525b99 124
WilliamMarshQMUL 0:ad3cdc525b99 125 while (true) {
WilliamMarshQMUL 0:ad3cdc525b99 126 osEvent evt = mailbox.get(); // wait for mail
WilliamMarshQMUL 0:ad3cdc525b99 127 if (evt.status == osEventMail) {
WilliamMarshQMUL 0:ad3cdc525b99 128 message_t* mess = (message_t*)evt.value.p ;
WilliamMarshQMUL 0:ad3cdc525b99 129 volts = (mess->analog * 330) / 0xffff ;
anair12345 5:beff003ed7e0 130 int mypressEvent = mess->button;
WilliamMarshQMUL 0:ad3cdc525b99 131 mailbox.free(mess) ; // free the message space
anair12345 5:beff003ed7e0 132 if(mypressEvent) {
anair12345 5:beff003ed7e0 133 for(int i = 0; i<5;i++){
anair12345 5:beff003ed7e0 134 threshold[i] = (i*volts)/6;
anair12345 5:beff003ed7e0 135 }// use volts to reset thresholds
anair12345 5:beff003ed7e0 136 }
anair12345 5:beff003ed7e0 137 if (volts > threshold[0] ) led0 = 1 ; else led0 = 0 ;
anair12345 5:beff003ed7e0 138 if (volts > threshold[1]) led1 = 1 ; else led1 = 0 ;
anair12345 5:beff003ed7e0 139 if (volts > threshold[2]) led2 = 1 ; else led2 = 0 ;
anair12345 5:beff003ed7e0 140 if (volts > threshold[3]) led3 = 1 ; else led3 = 0 ;
anair12345 5:beff003ed7e0 141 if (volts > threshold[4]) led4 = 1 ; else led4 = 0 ;
WilliamMarshQMUL 0:ad3cdc525b99 142 vToString(volts, vstring) ;
WilliamMarshQMUL 0:ad3cdc525b99 143 counter++ ;
WilliamMarshQMUL 0:ad3cdc525b99 144 if (counter == 10) { // limit bandwidth of serial
WilliamMarshQMUL 0:ad3cdc525b99 145 pc.printf(vstring) ;
WilliamMarshQMUL 0:ad3cdc525b99 146 counter = 0 ;
WilliamMarshQMUL 0:ad3cdc525b99 147 }
WilliamMarshQMUL 0:ad3cdc525b99 148 }
WilliamMarshQMUL 0:ad3cdc525b99 149 }
WilliamMarshQMUL 0:ad3cdc525b99 150 }