Mike Pollock / Mbed 2 deprecated GT_Tuner2

Slight modifications to original for different LCD and mbed pin outs

Dependencies:   mbed

Fork of GT_Tuner by Andrew Durand

main.cpp@2:0b7bf57470c4, 2016-12-16 (annotated)

Committer:
mptapton
Date:
Fri Dec 16 10:15:01 2016 +0000
Revision:
2:0b7bf57470c4
Parent:
1:ae7d0cf78b3e 
Original code modified for a different LCD and mbed pin out. Additional output to LCD for real time input signal value

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mptapton 2:0b7bf57470c4 1 //////////////////////////////////////////
adurand 0:490e67fb09c2 2 // //
adurand 0:490e67fb09c2 3 // Guitar Tuner via Goertzel's Algorithm //
adurand 0:490e67fb09c2 4 // Created by: Andrew Durand //
adurand 0:490e67fb09c2 5 // //
adurand 0:490e67fb09c2 6 //////////////////////////////////////////
mptapton 2:0b7bf57470c4 7 #include "TextLCD.h"
adurand 0:490e67fb09c2 8 #include "mbed.h"
adurand 0:490e67fb09c2 9 #include "adc.h"
mptapton 2:0b7bf57470c4 10 //#include "NokiaLCD.h"
adurand 1:ae7d0cf78b3e 11 #include <math.h>
adurand 0:490e67fb09c2 12 #define PI 3.1415
adurand 0:490e67fb09c2 13 #define SAMPLE_RATE 24000
adurand 0:490e67fb09c2 14
adurand 0:490e67fb09c2 15 DigitalOut led_low(LED1);
adurand 0:490e67fb09c2 16 DigitalOut led_ok(LED2);
adurand 0:490e67fb09c2 17 DigitalOut led_high(LED4);
mptapton 2:0b7bf57470c4 18 InterruptIn button1(p6); //mosi
adurand 0:490e67fb09c2 19
adurand 0:490e67fb09c2 20 //LCD and Other Random Variables
mptapton 2:0b7bf57470c4 21 //NokiaLCD lcd(p5, p7, p8, p9, NokiaLCD::LCD6610); // mosi, sclk, cs, rst, type
mptapton 2:0b7bf57470c4 22
mptapton 2:0b7bf57470c4 23 /* This code uses libraries created for 4-bit LCD's based on the HD44780. This
mptapton 2:0b7bf57470c4 24 program was designed for a similar product (Winstar's WH1602B 2x16 LC) working
mptapton 2:0b7bf57470c4 25 into an Mbed LPC1768.
mptapton 2:0b7bf57470c4 26 LCD pins: Pin 1(VSS) to Mbed Gnd, Pin 2(VDD) to Mbed VOUT, Pin 3(Vo- contrast)
mptapton 2:0b7bf57470c4 27 to Mbed Gnd, Pin 5(R/W) to Mbed Gnd, Pin 15(A)to Mbed VOUT, Pin 16(B) to
mptapton 2:0b7bf57470c4 28 MBed Gnd, Pins 4(RS),20(E) and the 4 data bits (DB4 [11] through to DB7 [14])
mptapton 2:0b7bf57470c4 29 go to the Mbed pins described below: */
mptapton 2:0b7bf57470c4 30
mptapton 2:0b7bf57470c4 31 TextLCD lcd(p10, p12, p15, p16, p29, p30); // rs, e, d4-d7
mptapton 2:0b7bf57470c4 32
adurand 0:490e67fb09c2 33 int string_select = 0;
adurand 1:ae7d0cf78b3e 34 float high, high1, in_tune, in_tune1, in_tune2, in_tune3,
adurand 1:ae7d0cf78b3e 35 low, low1, note, low_mod, high_mod;
adurand 0:490e67fb09c2 36 char* key;
adurand 0:490e67fb09c2 37 int Counter = 0;
adurand 0:490e67fb09c2 38 int Buffer[6000];
adurand 0:490e67fb09c2 39
adurand 0:490e67fb09c2 40 float goertzelFilter(int samples[], float freq, int N) {
adurand 0:490e67fb09c2 41 float s_prev = 0.0;
adurand 0:490e67fb09c2 42 float s_prev2 = 0.0;
mptapton 2:0b7bf57470c4 43 float coeff,normalizedfreq,power,s; //k was defined here but nolonger needed
adurand 0:490e67fb09c2 44 int i;
adurand 0:490e67fb09c2 45 normalizedfreq = freq / SAMPLE_RATE;
adurand 0:490e67fb09c2 46 coeff = 2*cos(2*PI*normalizedfreq);
adurand 0:490e67fb09c2 47 for (i=0; i<N; i++) {
adurand 0:490e67fb09c2 48 s = samples[i] + coeff * s_prev - s_prev2;
adurand 0:490e67fb09c2 49 s_prev2 = s_prev;
adurand 0:490e67fb09c2 50 s_prev = s;
adurand 0:490e67fb09c2 51 }
adurand 0:490e67fb09c2 52 power = s_prev2*s_prev2+s_prev*s_prev-coeff*s_prev*s_prev2;
adurand 0:490e67fb09c2 53 return power;
adurand 0:490e67fb09c2 54 }
adurand 0:490e67fb09c2 55
adurand 0:490e67fb09c2 56 ADC adc(SAMPLE_RATE, 1);
adurand 0:490e67fb09c2 57
adurand 0:490e67fb09c2 58 void sample_audio(int chan, uint32_t value) {
adurand 0:490e67fb09c2 59 Buffer[Counter] = adc.read(p20);
adurand 0:490e67fb09c2 60 Counter += 1;
adurand 0:490e67fb09c2 61 }
adurand 0:490e67fb09c2 62
adurand 0:490e67fb09c2 63 void button1_pressed() {
adurand 0:490e67fb09c2 64 string_select++;
adurand 0:490e67fb09c2 65 if (string_select > 5) string_select = 0;
adurand 0:490e67fb09c2 66 }
adurand 0:490e67fb09c2 67
adurand 0:490e67fb09c2 68 int main() {
adurand 0:490e67fb09c2 69 //Interupt for Switching Strings
adurand 0:490e67fb09c2 70 button1.mode(PullDown);
adurand 0:490e67fb09c2 71 button1.rise(&button1_pressed);
adurand 0:490e67fb09c2 72
adurand 0:490e67fb09c2 73 //Setup LCD
mptapton 2:0b7bf57470c4 74 // lcd.background(0xF0000F);
adurand 0:490e67fb09c2 75 lcd.cls();
adurand 0:490e67fb09c2 76
adurand 0:490e67fb09c2 77 while (1) {
adurand 0:490e67fb09c2 78
adurand 0:490e67fb09c2 79 switch (string_select) {
adurand 0:490e67fb09c2 80 case 0:
adurand 0:490e67fb09c2 81 note = 82;
adurand 0:490e67fb09c2 82 key= "E2";
adurand 0:490e67fb09c2 83 break;
adurand 0:490e67fb09c2 84 case 1:
adurand 0:490e67fb09c2 85 note = 110;
adurand 0:490e67fb09c2 86 key= "A2";
adurand 0:490e67fb09c2 87 break;
adurand 0:490e67fb09c2 88 case 2:
adurand 0:490e67fb09c2 89 note = 147;
adurand 0:490e67fb09c2 90 key= "D3";
adurand 0:490e67fb09c2 91 break;
adurand 0:490e67fb09c2 92 case 3:
adurand 0:490e67fb09c2 93 note = 196;
adurand 0:490e67fb09c2 94 key= "G3";
adurand 0:490e67fb09c2 95 break;
adurand 0:490e67fb09c2 96 case 4:
adurand 0:490e67fb09c2 97 note = 247;
adurand 0:490e67fb09c2 98 key= "B3";
adurand 0:490e67fb09c2 99 break;
adurand 0:490e67fb09c2 100 case 5:
adurand 0:490e67fb09c2 101 note = 330;
adurand 0:490e67fb09c2 102 key= "E4";
adurand 0:490e67fb09c2 103 break;
adurand 0:490e67fb09c2 104 }
adurand 0:490e67fb09c2 105
adurand 0:490e67fb09c2 106 //Prepare for burst mode on all ADC pins and set up interrupt handler (using ADC library from Simon Blandford
adurand 0:490e67fb09c2 107 adc.append(sample_audio);
adurand 0:490e67fb09c2 108 adc.startmode(0,0);
adurand 0:490e67fb09c2 109 adc.burst(1);
adurand 0:490e67fb09c2 110 adc.setup(p20,1);
adurand 0:490e67fb09c2 111
adurand 0:490e67fb09c2 112 //start the interrupt and wait for about 4096 samples
adurand 0:490e67fb09c2 113 adc.interrupt_state(p20,1);
adurand 0:490e67fb09c2 114 wait(.2);
adurand 0:490e67fb09c2 115
adurand 0:490e67fb09c2 116 //Finsh up - Unset pin 20
adurand 0:490e67fb09c2 117 adc.interrupt_state(p20,0);
adurand 0:490e67fb09c2 118 adc.setup(p20,0);
adurand 0:490e67fb09c2 119 int actual_rate = adc.actual_sample_rate();
adurand 0:490e67fb09c2 120
adurand 0:490e67fb09c2 121 //for debugging tell the terminal sample rate and how many samples we took
adurand 0:490e67fb09c2 122 printf("Requested max sample rate is %u, actual max sample rate is %u.\n",
adurand 0:490e67fb09c2 123 SAMPLE_RATE, actual_rate);
adurand 0:490e67fb09c2 124 printf("We did %i samples\n",Counter);
adurand 0:490e67fb09c2 125
adurand 1:ae7d0cf78b3e 126 high = 0;
adurand 1:ae7d0cf78b3e 127 low = 0;
adurand 1:ae7d0cf78b3e 128 for (int i=3; i<46; i+=3) {
adurand 1:ae7d0cf78b3e 129 high1 = goertzelFilter(Buffer, (note + i ), Counter);
adurand 1:ae7d0cf78b3e 130 if (high1 > high) high=high1;
adurand 1:ae7d0cf78b3e 131 }
adurand 1:ae7d0cf78b3e 132 for (int i=3; i<46; i+=3) {
adurand 1:ae7d0cf78b3e 133 low1 = goertzelFilter(Buffer, (note - i ), Counter);
adurand 1:ae7d0cf78b3e 134 if (low1 > low) low=low1;
adurand 1:ae7d0cf78b3e 135 }
adurand 1:ae7d0cf78b3e 136 in_tune1 = goertzelFilter(Buffer, (note+1), Counter);
adurand 0:490e67fb09c2 137 in_tune2 = goertzelFilter(Buffer, note, Counter);
adurand 1:ae7d0cf78b3e 138 in_tune3 = goertzelFilter(Buffer, (note-1), Counter);
adurand 1:ae7d0cf78b3e 139
adurand 1:ae7d0cf78b3e 140 if ((in_tune1 > in_tune2) && (in_tune1 > in_tune3)) in_tune = in_tune1;
adurand 1:ae7d0cf78b3e 141 else if ((in_tune2 > in_tune1) && (in_tune2 > in_tune3)) in_tune = in_tune2;
adurand 1:ae7d0cf78b3e 142 else in_tune = in_tune3;
adurand 1:ae7d0cf78b3e 143 // printf("high = %.2f, low = %.2f, in_tune = %.2f", high, low, in_tune);
adurand 1:ae7d0cf78b3e 144 // high_mod = high/in_tune;
adurand 1:ae7d0cf78b3e 145 // low_mod = low/in_tune;
adurand 1:ae7d0cf78b3e 146 // if ((high_mod > .8)&&(low_mod > .8)) {
adurand 1:ae7d0cf78b3e 147 // led_high = 0;
adurand 1:ae7d0cf78b3e 148 // led_ok = 0;
adurand 1:ae7d0cf78b3e 149 // led_low = 0;
adurand 1:ae7d0cf78b3e 150 // }
adurand 0:490e67fb09c2 151 if ((in_tune > high) && (in_tune > low)) {
adurand 0:490e67fb09c2 152 led_high = 0;
adurand 0:490e67fb09c2 153 led_ok = 1;
adurand 0:490e67fb09c2 154 led_low = 0;
adurand 0:490e67fb09c2 155 } else if (high > in_tune) {
adurand 0:490e67fb09c2 156 led_high = 1;
adurand 0:490e67fb09c2 157 led_ok = 0;
adurand 0:490e67fb09c2 158 led_low = 0;
adurand 0:490e67fb09c2 159 } else if (low > in_tune) {
adurand 0:490e67fb09c2 160 led_high = 0;
adurand 0:490e67fb09c2 161 led_ok = 0;
adurand 0:490e67fb09c2 162 led_low = 1;
adurand 0:490e67fb09c2 163 } else {
adurand 0:490e67fb09c2 164 led_high = 0;
adurand 0:490e67fb09c2 165 led_ok = 0;
adurand 0:490e67fb09c2 166 led_low = 0;
adurand 0:490e67fb09c2 167 }
adurand 1:ae7d0cf78b3e 168
adurand 0:490e67fb09c2 169 // Display on the LCD
mptapton 2:0b7bf57470c4 170 // lcd.locate(0,1);
mptapton 2:0b7bf57470c4 171 // lcd.printf("Guitar Tuner");
mptapton 2:0b7bf57470c4 172 // lcd.locate(0,3);
mptapton 2:0b7bf57470c4 173 // lcd.printf("Tuning String: %i", (6-string_select));
mptapton 2:0b7bf57470c4 174 int pintwenty = adc.read(p20); //read pin 20
adurand 0:490e67fb09c2 175 lcd.locate(0,1);
mptapton 2:0b7bf57470c4 176 lcd.printf("%s %iHz %d\n",key, (int) note, pintwenty);
mptapton 2:0b7bf57470c4 177 // lcd.locate(0,2);
mptapton 2:0b7bf57470c4 178 if (led_ok) lcd.printf("Ok ");
mptapton 2:0b7bf57470c4 179 else if (led_low) lcd.printf("Low ");
mptapton 2:0b7bf57470c4 180 else if (led_high) lcd.printf("High");
adurand 1:ae7d0cf78b3e 181 else lcd.printf("~~~~~~~~");
adurand 0:490e67fb09c2 182
adurand 0:490e67fb09c2 183 Counter = 0;
adurand 0:490e67fb09c2 184
adurand 0:490e67fb09c2 185 }
adurand 0:490e67fb09c2 186
adurand 0:490e67fb09c2 187
mptapton 2:0b7bf57470c4 188
adurand 0:490e67fb09c2 189 }