Soheil Novinfard / Mbed OS ADCandticker_modified_2

AnalougeToDigital Converter

Fork of ADCandticker_sample by William Marsh

main.cpp@2:24a06c840c25, 2018-02-08 (annotated)

Committer:
novinfard
Date:
Thu Feb 08 16:16:01 2018 +0000
Revision:
2:24a06c840c25
Parent:
1:126dd2f5fc2d 
Project Lab3 (Part 1) finished

Who changed what in which revision?

UserRevisionLine numberNew contents of line
WilliamMarshQMUL 0:ad3cdc525b99 1
WilliamMarshQMUL 0:ad3cdc525b99 2 // LAB 3 SAMPLE PROGRAM 1
WilliamMarshQMUL 1:126dd2f5fc2d 3 // Revised for mbed 5
WilliamMarshQMUL 0:ad3cdc525b99 4
WilliamMarshQMUL 0:ad3cdc525b99 5 #include "mbed.h"
WilliamMarshQMUL 1:126dd2f5fc2d 6
WilliamMarshQMUL 0:ad3cdc525b99 7
WilliamMarshQMUL 0:ad3cdc525b99 8 Ticker tick; // Ticker for reading analog
WilliamMarshQMUL 0:ad3cdc525b99 9 AnalogIn ain(A0) ; // Analog input
novinfard 2:24a06c840c25 10 DigitalOut led1(PTA12);
novinfard 2:24a06c840c25 11 DigitalOut led2(PTA4);
novinfard 2:24a06c840c25 12 DigitalOut led3(PTA5);
novinfard 2:24a06c840c25 13 DigitalOut led4(PTC8);
novinfard 2:24a06c840c25 14 DigitalOut led5(PTC9);
novinfard 2:24a06c840c25 15 Serial pc(USBTX, USBRX); // tx, rx, for debugging
novinfard 2:24a06c840c25 16
novinfard 2:24a06c840c25 17 DigitalIn b1(PTD0, PullUp);
novinfard 2:24a06c840c25 18
novinfard 2:24a06c840c25 19 volatile int pressEvent = 0 ; // Variabe set by the polling thread
novinfard 2:24a06c840c25 20
novinfard 2:24a06c840c25 21 enum buttonPos { up, down, bounce }; // Button positions
novinfard 2:24a06c840c25 22 void polling()
novinfard 2:24a06c840c25 23 {
novinfard 2:24a06c840c25 24 buttonPos pos = up ;
novinfard 2:24a06c840c25 25 int bcounter = 0 ;
WilliamMarshQMUL 0:ad3cdc525b99 26
novinfard 2:24a06c840c25 27 switch (pos) {
novinfard 2:24a06c840c25 28 case up :
novinfard 2:24a06c840c25 29 if (!b1.read()) { // now down
novinfard 2:24a06c840c25 30 pressEvent = 1 ; // transition occurred
novinfard 2:24a06c840c25 31 pos = down ;
novinfard 2:24a06c840c25 32 }
novinfard 2:24a06c840c25 33 break ;
novinfard 2:24a06c840c25 34 case down :
novinfard 2:24a06c840c25 35 if (b1 == 1) { // no longer down
novinfard 2:24a06c840c25 36 bcounter = 3 ; // wait four cycles
novinfard 2:24a06c840c25 37 pos = bounce ;
novinfard 2:24a06c840c25 38 }
novinfard 2:24a06c840c25 39 break ;
novinfard 2:24a06c840c25 40 case bounce :
novinfard 2:24a06c840c25 41 if (b1 == 0) { // down again - button has bounced
novinfard 2:24a06c840c25 42 pos = down ; // no event
novinfard 2:24a06c840c25 43 } else if (bcounter == 0) {
novinfard 2:24a06c840c25 44 pos = up ; // delay passed - reset to up
novinfard 2:24a06c840c25 45 } else {
novinfard 2:24a06c840c25 46 bcounter-- ; // continue waiting
novinfard 2:24a06c840c25 47 }
novinfard 2:24a06c840c25 48 break ;
novinfard 2:24a06c840c25 49
novinfard 2:24a06c840c25 50 }
novinfard 2:24a06c840c25 51 }
WilliamMarshQMUL 0:ad3cdc525b99 52
WilliamMarshQMUL 0:ad3cdc525b99 53 // Message type
WilliamMarshQMUL 0:ad3cdc525b99 54 typedef struct {
novinfard 2:24a06c840c25 55 uint16_t analog; /* Analog input value */
WilliamMarshQMUL 0:ad3cdc525b99 56 } message_t;
WilliamMarshQMUL 0:ad3cdc525b99 57
WilliamMarshQMUL 0:ad3cdc525b99 58 // Mail box
WilliamMarshQMUL 0:ad3cdc525b99 59 Mail<message_t, 2> mailbox;
WilliamMarshQMUL 0:ad3cdc525b99 60
WilliamMarshQMUL 0:ad3cdc525b99 61 // Function called every 10ms to read ADC
novinfard 2:24a06c840c25 62 // Low pass filter
WilliamMarshQMUL 0:ad3cdc525b99 63 // Every 10th value is sent to mailbox
WilliamMarshQMUL 0:ad3cdc525b99 64 volatile int samples = 0 ;
novinfard 2:24a06c840c25 65 volatile uint16_t smoothed = 0 ;
novinfard 2:24a06c840c25 66 void readA0()
novinfard 2:24a06c840c25 67 {
novinfard 2:24a06c840c25 68 polling();
novinfard 2:24a06c840c25 69 smoothed = (smoothed >> 1) + (ain.read_u16() >> 1) ; // divided by 2 - reduce the signal noise
WilliamMarshQMUL 0:ad3cdc525b99 70 samples++ ;
WilliamMarshQMUL 0:ad3cdc525b99 71 if (samples == 10) {
WilliamMarshQMUL 0:ad3cdc525b99 72 // send to thread
WilliamMarshQMUL 0:ad3cdc525b99 73 message_t *mess = mailbox.alloc() ; // may fail but does not block
WilliamMarshQMUL 0:ad3cdc525b99 74 if (mess) {
WilliamMarshQMUL 0:ad3cdc525b99 75 mess->analog = smoothed ;
WilliamMarshQMUL 0:ad3cdc525b99 76 mailbox.put(mess); // fails but does not block if full
WilliamMarshQMUL 0:ad3cdc525b99 77 }
WilliamMarshQMUL 0:ad3cdc525b99 78 samples = 0;
novinfard 2:24a06c840c25 79 }
WilliamMarshQMUL 0:ad3cdc525b99 80 }
WilliamMarshQMUL 0:ad3cdc525b99 81
WilliamMarshQMUL 0:ad3cdc525b99 82 // Write voltage digits
WilliamMarshQMUL 0:ad3cdc525b99 83 // v Voltage as scale int, e.g. 3.30 is 330
novinfard 2:24a06c840c25 84 void vToString(int v, char* s)
novinfard 2:24a06c840c25 85 {
WilliamMarshQMUL 0:ad3cdc525b99 86 s[3] = '0' + (v % 10) ;
WilliamMarshQMUL 0:ad3cdc525b99 87 v = v / 10 ;
WilliamMarshQMUL 0:ad3cdc525b99 88 s[2] = '0' + (v % 10) ;
WilliamMarshQMUL 0:ad3cdc525b99 89 v = v / 10 ;
WilliamMarshQMUL 0:ad3cdc525b99 90 s[0] = '0' + (v % 10) ;
WilliamMarshQMUL 0:ad3cdc525b99 91 }
WilliamMarshQMUL 0:ad3cdc525b99 92
WilliamMarshQMUL 0:ad3cdc525b99 93 // Main program
WilliamMarshQMUL 0:ad3cdc525b99 94 // Initialise variables
WilliamMarshQMUL 0:ad3cdc525b99 95 // Attach ISR for ticker
novinfard 2:24a06c840c25 96 // Procss messages from mailbox
novinfard 2:24a06c840c25 97 int main()
novinfard 2:24a06c840c25 98 {
novinfard 2:24a06c840c25 99 led1 = 1 ; // turn off
WilliamMarshQMUL 0:ad3cdc525b99 100 int volts = 0 ;
novinfard 2:24a06c840c25 101 int threshold = 100 ; // 1 vol
WilliamMarshQMUL 0:ad3cdc525b99 102 int counter = 0 ;
WilliamMarshQMUL 0:ad3cdc525b99 103 char vstring[] = "X.XX\r\n" ;
WilliamMarshQMUL 0:ad3cdc525b99 104
novinfard 2:24a06c840c25 105 tick.attach_us(callback(&readA0), 10000); // ticks every 10ms -> 10000 micro second
novinfard 2:24a06c840c25 106
novinfard 2:24a06c840c25 107
WilliamMarshQMUL 0:ad3cdc525b99 108 while (true) {
novinfard 2:24a06c840c25 109 osEvent evt = mailbox.get(); // wait for mail
novinfard 2:24a06c840c25 110
novinfard 2:24a06c840c25 111
novinfard 2:24a06c840c25 112
novinfard 2:24a06c840c25 113 // every 100 ms this loop operates
WilliamMarshQMUL 0:ad3cdc525b99 114 if (evt.status == osEventMail) {
WilliamMarshQMUL 0:ad3cdc525b99 115 message_t* mess = (message_t*)evt.value.p ;
novinfard 2:24a06c840c25 116 volts = (mess->analog * 330) / 0xffff ; // 2 ^ 16
novinfard 2:24a06c840c25 117
novinfard 2:24a06c840c25 118 if (pressEvent) {
novinfard 2:24a06c840c25 119 pressEvent = 0 ; // clear the event variable
novinfard 2:24a06c840c25 120 threshold = volts;
novinfard 2:24a06c840c25 121
novinfard 2:24a06c840c25 122 }
novinfard 2:24a06c840c25 123
WilliamMarshQMUL 0:ad3cdc525b99 124 mailbox.free(mess) ; // free the message space
novinfard 2:24a06c840c25 125 if(volts < (threshold / 6)) {
novinfard 2:24a06c840c25 126 led1 = 0;
novinfard 2:24a06c840c25 127 led2 = 0;
novinfard 2:24a06c840c25 128 led3 = 0;
novinfard 2:24a06c840c25 129 led4 = 0;
novinfard 2:24a06c840c25 130 led5 = 0;
novinfard 2:24a06c840c25 131 }
novinfard 2:24a06c840c25 132 if((volts > (threshold * 1/ 6))&&(volts < (threshold * 2/ 6))) {
novinfard 2:24a06c840c25 133 led1 = 1;
novinfard 2:24a06c840c25 134 led2 = 0;
novinfard 2:24a06c840c25 135 led3 = 0;
novinfard 2:24a06c840c25 136 led4 = 0;
novinfard 2:24a06c840c25 137 led5 = 0;
novinfard 2:24a06c840c25 138 }
novinfard 2:24a06c840c25 139 if((volts > (threshold * 2/ 6))&&(volts < (threshold * 3/ 6))) {
novinfard 2:24a06c840c25 140 led1 = 1;
novinfard 2:24a06c840c25 141 led2 = 1;
novinfard 2:24a06c840c25 142 led3 = 0;
novinfard 2:24a06c840c25 143 led4 = 0;
novinfard 2:24a06c840c25 144 led5 = 0;
novinfard 2:24a06c840c25 145 }
novinfard 2:24a06c840c25 146 if((volts > (threshold * 3/ 6))&&(volts < (threshold * 4/ 6))) {
novinfard 2:24a06c840c25 147 led1 = 1;
novinfard 2:24a06c840c25 148 led2 = 1;
novinfard 2:24a06c840c25 149 led3 = 1;
novinfard 2:24a06c840c25 150 led4 = 0;
novinfard 2:24a06c840c25 151 led5 = 0;
novinfard 2:24a06c840c25 152 }
novinfard 2:24a06c840c25 153 if((volts > (threshold * 4/ 6))&&(volts < (threshold * 5/ 6))) {
novinfard 2:24a06c840c25 154 led1 = 1;
novinfard 2:24a06c840c25 155 led2 = 1;
novinfard 2:24a06c840c25 156 led3 = 1;
novinfard 2:24a06c840c25 157 led4 = 1;
novinfard 2:24a06c840c25 158 led5 = 0;
novinfard 2:24a06c840c25 159 }
novinfard 2:24a06c840c25 160 if(volts > (threshold * 5/ 6)) {
novinfard 2:24a06c840c25 161 led1 = 1;
novinfard 2:24a06c840c25 162 led2 = 1;
novinfard 2:24a06c840c25 163 led3 = 1;
novinfard 2:24a06c840c25 164 led4 = 1;
novinfard 2:24a06c840c25 165 led5 = 1;
novinfard 2:24a06c840c25 166 }
WilliamMarshQMUL 0:ad3cdc525b99 167 vToString(volts, vstring) ;
WilliamMarshQMUL 0:ad3cdc525b99 168 counter++ ;
novinfard 2:24a06c840c25 169
novinfard 2:24a06c840c25 170 // every 1 s this loop will operate
WilliamMarshQMUL 0:ad3cdc525b99 171 if (counter == 10) { // limit bandwidth of serial
WilliamMarshQMUL 0:ad3cdc525b99 172 pc.printf(vstring) ;
WilliamMarshQMUL 0:ad3cdc525b99 173 counter = 0 ;
WilliamMarshQMUL 0:ad3cdc525b99 174 }
WilliamMarshQMUL 0:ad3cdc525b99 175 }
WilliamMarshQMUL 0:ad3cdc525b99 176
WilliamMarshQMUL 0:ad3cdc525b99 177 }
WilliamMarshQMUL 0:ad3cdc525b99 178 }