Yue Kong / Mbed 2 deprecated WoYaoChengGOng

Change the Ledstrip with Different input signal frequency

Dependencies:   PololuLedStrip mbed

main.cpp@0:dc6175686e56, 2014-07-28 (annotated)

Committer:
KongXiangyue
Date:
Mon Jul 28 13:48:16 2014 +0000
Revision:
0:dc6175686e56
FFT input analogue and drive the PololuLed strip

Who changed what in which revision?

UserRevisionLine numberNew contents of line
KongXiangyue 0:dc6175686e56 1 #define SAMPLE_RATE 48000
KongXiangyue 0:dc6175686e56 2
KongXiangyue 0:dc6175686e56 3
KongXiangyue 0:dc6175686e56 4 #include "mbed.h"
KongXiangyue 0:dc6175686e56 5 #include "adc.h"
KongXiangyue 0:dc6175686e56 6 #include "PololuLedStrip.h"
KongXiangyue 0:dc6175686e56 7
KongXiangyue 0:dc6175686e56 8 PololuLedStrip ledStrip(p8);
KongXiangyue 0:dc6175686e56 9
KongXiangyue 0:dc6175686e56 10 #define LED_COUNT 60
KongXiangyue 0:dc6175686e56 11 rgb_color colors[LED_COUNT];
KongXiangyue 0:dc6175686e56 12
KongXiangyue 0:dc6175686e56 13 Serial pc(USBTX,USBRX);
KongXiangyue 0:dc6175686e56 14
KongXiangyue 0:dc6175686e56 15 //extern "C" void cr4_fft_256_stm32(void *pssOUT, void *pssIN, uint16_t Nbin);
KongXiangyue 0:dc6175686e56 16 extern "C" void fftR4(short *y, short *x, int N);
KongXiangyue 0:dc6175686e56 17
KongXiangyue 0:dc6175686e56 18 //use the LED as a bargraph
KongXiangyue 0:dc6175686e56 19 DigitalOut l1(LED1);
KongXiangyue 0:dc6175686e56 20 DigitalOut l2(LED2);
KongXiangyue 0:dc6175686e56 21 DigitalOut l3(LED3);
KongXiangyue 0:dc6175686e56 22 DigitalOut l4(LED4);
KongXiangyue 0:dc6175686e56 23
KongXiangyue 0:dc6175686e56 24 //set up a timer for timing FFT's
KongXiangyue 0:dc6175686e56 25 Timer timer;
KongXiangyue 0:dc6175686e56 26
KongXiangyue 0:dc6175686e56 27 //Used to change colour of LED strips
KongXiangyue 0:dc6175686e56 28 //int testX = 0;
KongXiangyue 0:dc6175686e56 29
KongXiangyue 0:dc6175686e56 30 //Set up filesystem so we can write some useful files
KongXiangyue 0:dc6175686e56 31
KongXiangyue 0:dc6175686e56 32 LocalFileSystem local("local");
KongXiangyue 0:dc6175686e56 33 FILE *fp;
KongXiangyue 0:dc6175686e56 34
KongXiangyue 0:dc6175686e56 35 //Set up a global buffer for audio data so interrupt can access it
KongXiangyue 0:dc6175686e56 36 int Counter = 0;
KongXiangyue 0:dc6175686e56 37 int16_t Buffer[5000];
KongXiangyue 0:dc6175686e56 38 int16_t VoltageBuffer[5000];
KongXiangyue 0:dc6175686e56 39
KongXiangyue 0:dc6175686e56 40 //Initialise ADC to maximum SAMPLE_RATE and cclk divide set to 1
KongXiangyue 0:dc6175686e56 41 ADC adc(SAMPLE_RATE, 1);
KongXiangyue 0:dc6175686e56 42
KongXiangyue 0:dc6175686e56 43 int colourVoltage=0;
KongXiangyue 0:dc6175686e56 44
KongXiangyue 0:dc6175686e56 45
KongXiangyue 0:dc6175686e56 46
KongXiangyue 0:dc6175686e56 47 //Our interrupt handler for audio sampling
KongXiangyue 0:dc6175686e56 48 void sample_ADC(int chan, uint32_t value) {
KongXiangyue 0:dc6175686e56 49
KongXiangyue 0:dc6175686e56 50 float s;
KongXiangyue 0:dc6175686e56 51 s = adc.read(p20);
KongXiangyue 0:dc6175686e56 52 int16_t b = (s -2048)*16;
KongXiangyue 0:dc6175686e56 53 Buffer[Counter] = b;
KongXiangyue 0:dc6175686e56 54
KongXiangyue 0:dc6175686e56 55 Counter += 1;
KongXiangyue 0:dc6175686e56 56 /* bar graph */
KongXiangyue 0:dc6175686e56 57
KongXiangyue 0:dc6175686e56 58 int g = abs(s-2048);
KongXiangyue 0:dc6175686e56 59 l1 = g > 0.1f*2048;
KongXiangyue 0:dc6175686e56 60 l2 = g > 0.3f*2048;
KongXiangyue 0:dc6175686e56 61 l3 = g > 0.6f*2048;
KongXiangyue 0:dc6175686e56 62 l4 = g > 0.8f*2048;
KongXiangyue 0:dc6175686e56 63 }
KongXiangyue 0:dc6175686e56 64
KongXiangyue 0:dc6175686e56 65
KongXiangyue 0:dc6175686e56 66
KongXiangyue 0:dc6175686e56 67
KongXiangyue 0:dc6175686e56 68
KongXiangyue 0:dc6175686e56 69
KongXiangyue 0:dc6175686e56 70 int main() {
KongXiangyue 0:dc6175686e56 71
KongXiangyue 0:dc6175686e56 72 while (1){
KongXiangyue 0:dc6175686e56 73
KongXiangyue 0:dc6175686e56 74 //Prepare for burst mode on all ADC pins and set up interrupt handler (using ADC library from Simon Blandford
KongXiangyue 0:dc6175686e56 75 adc.append(sample_ADC);
KongXiangyue 0:dc6175686e56 76 adc.startmode(0,0);
KongXiangyue 0:dc6175686e56 77 adc.burst(1);
KongXiangyue 0:dc6175686e56 78 adc.setup(p20,1);
KongXiangyue 0:dc6175686e56 79 //introduce a delay as initial waveform has bias whilst decoupling cap charges
KongXiangyue 0:dc6175686e56 80 wait(0.05);
KongXiangyue 0:dc6175686e56 81 //start the interrupt and wait for about 4096 samples
KongXiangyue 0:dc6175686e56 82 adc.interrupt_state(p20,1);
KongXiangyue 0:dc6175686e56 83 wait(0.05);
KongXiangyue 0:dc6175686e56 84
KongXiangyue 0:dc6175686e56 85 //Finsh up - Unset pin 20
KongXiangyue 0:dc6175686e56 86 adc.interrupt_state(p20,0);
KongXiangyue 0:dc6175686e56 87 adc.setup(p20,0);
KongXiangyue 0:dc6175686e56 88 int actual_rate = adc.actual_sample_rate();
KongXiangyue 0:dc6175686e56 89 //now lets try mellen fft-------------------------
KongXiangyue 0:dc6175686e56 90 timer.reset();
KongXiangyue 0:dc6175686e56 91 timer.start();
KongXiangyue 0:dc6175686e56 92 #define MN 1024 /*Number of points*/
KongXiangyue 0:dc6175686e56 93 short mx[MN*2]; // input data 16 bit, 4 byte aligned x0r,x0i,x1r,x1i,....
KongXiangyue 0:dc6175686e56 94 short my[MN*2]; // output data 16 bit,4 byte aligned y0r,y0i,y1r,y1i,....
KongXiangyue 0:dc6175686e56 95 float mz[MN*2]; // to store the final result
KongXiangyue 0:dc6175686e56 96 for (int i=0;i<MN*2;i++) mx[i]=0;
KongXiangyue 0:dc6175686e56 97 for (int i=0;i<MN*2;i++) mz[i]=0;
KongXiangyue 0:dc6175686e56 98 for (int i=0;i<MN;i=i+1)
KongXiangyue 0:dc6175686e56 99 { mx[i*2]=Buffer[i];}
KongXiangyue 0:dc6175686e56 100 //printf("Mellen set up took %i\n",timer.read_us());
KongXiangyue 0:dc6175686e56 101 //call functions
KongXiangyue 0:dc6175686e56 102 timer.reset();
KongXiangyue 0:dc6175686e56 103 timer.start();
KongXiangyue 0:dc6175686e56 104 fftR4(my, mx, MN);
KongXiangyue 0:dc6175686e56 105 //printf("Mellen fft took %i\n",timer.read_us());
KongXiangyue 0:dc6175686e56 106 //FILE* mlog = fopen("/local/mellen.csv","w");
KongXiangyue 0:dc6175686e56 107
KongXiangyue 0:dc6175686e56 108 //now write a CSV file to filesytem of frequency vs amplitude
KongXiangyue 0:dc6175686e56 109 for (int i=0; i<MN; i=i+2)
KongXiangyue 0:dc6175686e56 110 {
KongXiangyue 0:dc6175686e56 111 // fprintf(mlog, "%d: %d -> %d\n", i, mx[i], my[i]);
KongXiangyue 0:dc6175686e56 112 //fprintf(mlog, "%d,%f\n", int(actual_rate/MN/2*i),sqrt(float( (my[i]*my[i]) +(my[i+1]*my[i+1]) ) ) );
KongXiangyue 0:dc6175686e56 113
KongXiangyue 0:dc6175686e56 114 mz[i]=sqrt(float( (my[i]*my[i]) +(my[i+1]*my[i+1]) ) ) ;
KongXiangyue 0:dc6175686e56 115 //fprintf(mlog, "%f\n", mz[i] );
KongXiangyue 0:dc6175686e56 116 }
KongXiangyue 0:dc6175686e56 117
KongXiangyue 0:dc6175686e56 118
KongXiangyue 0:dc6175686e56 119 // detect the change of input frequency ******************************
KongXiangyue 0:dc6175686e56 120 float maxFreq=0;
KongXiangyue 0:dc6175686e56 121 float max=0;
KongXiangyue 0:dc6175686e56 122 for (int i=2;i<512;i=i+1){
KongXiangyue 0:dc6175686e56 123
KongXiangyue 0:dc6175686e56 124 if(mz[i]>max){
KongXiangyue 0:dc6175686e56 125 max = mz[i];
KongXiangyue 0:dc6175686e56 126 maxFreq=i;
KongXiangyue 0:dc6175686e56 127 }//end if
KongXiangyue 0:dc6175686e56 128
KongXiangyue 0:dc6175686e56 129 }//end for
KongXiangyue 0:dc6175686e56 130 //fprintf(mlog, "%d\n",maxFreq );
KongXiangyue 0:dc6175686e56 131
KongXiangyue 0:dc6175686e56 132 int maxVoltage=0;
KongXiangyue 0:dc6175686e56 133 for (int i=0;i<512;i=i+1){
KongXiangyue 0:dc6175686e56 134
KongXiangyue 0:dc6175686e56 135 if(mx[i]>maxVoltage){
KongXiangyue 0:dc6175686e56 136 maxVoltage = mx[i];
KongXiangyue 0:dc6175686e56 137
KongXiangyue 0:dc6175686e56 138 }//end if
KongXiangyue 0:dc6175686e56 139 }//end for
KongXiangyue 0:dc6175686e56 140
KongXiangyue 0:dc6175686e56 141 pc.printf(" the max = %f\n",max );
KongXiangyue 0:dc6175686e56 142 pc.printf(" the maxFreq = %f\n",maxFreq );
KongXiangyue 0:dc6175686e56 143 pc.printf(" the colourValtage = %d\n", maxVoltage );
KongXiangyue 0:dc6175686e56 144
KongXiangyue 0:dc6175686e56 145
KongXiangyue 0:dc6175686e56 146 /*for (int i = 0; i < LED_COUNT; i++){
KongXiangyue 0:dc6175686e56 147 colors[i] = (rgb_color){ 0, 0, 0 };
KongXiangyue 0:dc6175686e56 148 }
KongXiangyue 0:dc6175686e56 149
KongXiangyue 0:dc6175686e56 150 if (maxFreq>60) maxFreq=60; // Limiting Length
KongXiangyue 0:dc6175686e56 151
KongXiangyue 0:dc6175686e56 152 for (int i = 0; i < maxFreq; i++){
KongXiangyue 0:dc6175686e56 153 colors[i] = (rgb_color){ abs(maxVoltage/11),abs(255-(maxVoltage/11)) ,abs(255-(maxVoltage/11)+50) };
KongXiangyue 0:dc6175686e56 154 }
KongXiangyue 0:dc6175686e56 155 ledStrip.write(colors, LED_COUNT);*/
KongXiangyue 0:dc6175686e56 156 int actualFreq= (actual_rate/MN/2*maxFreq);
KongXiangyue 0:dc6175686e56 157 pc.printf(" actualFreq = %d\n", actualFreq );
KongXiangyue 0:dc6175686e56 158
KongXiangyue 0:dc6175686e56 159
KongXiangyue 0:dc6175686e56 160 //wait_ms(10);
KongXiangyue 0:dc6175686e56 161
KongXiangyue 0:dc6175686e56 162 /*if (maxFreq>30){
KongXiangyue 0:dc6175686e56 163 //testX=200;
KongXiangyue 0:dc6175686e56 164 for (int i = 0; i < LED_COUNT; i++){
KongXiangyue 0:dc6175686e56 165 colors[i] = (rgb_color){ 0, 20, 200 };
KongXiangyue 0:dc6175686e56 166 }
KongXiangyue 0:dc6175686e56 167 }
KongXiangyue 0:dc6175686e56 168
KongXiangyue 0:dc6175686e56 169 if ((maxFreq>22)&&(maxFreq<30)){// if frequency bigger than 966Hz
KongXiangyue 0:dc6175686e56 170 //testX= 10;
KongXiangyue 0:dc6175686e56 171 for (int i = 0; i < LED_COUNT; i++){
KongXiangyue 0:dc6175686e56 172 colors[i] = (rgb_color){ 250, 0, 0 };
KongXiangyue 0:dc6175686e56 173
KongXiangyue 0:dc6175686e56 174 }
KongXiangyue 0:dc6175686e56 175 }
KongXiangyue 0:dc6175686e56 176 if (maxFreq<22){
KongXiangyue 0:dc6175686e56 177 //testX=200;
KongXiangyue 0:dc6175686e56 178 for (int i = 0; i < LED_COUNT; i++){
KongXiangyue 0:dc6175686e56 179 colors[i] = (rgb_color){ 0, 250, 0 };
KongXiangyue 0:dc6175686e56 180 }
KongXiangyue 0:dc6175686e56 181 }*/
KongXiangyue 0:dc6175686e56 182
KongXiangyue 0:dc6175686e56 183
KongXiangyue 0:dc6175686e56 184
KongXiangyue 0:dc6175686e56 185
KongXiangyue 0:dc6175686e56 186
KongXiangyue 0:dc6175686e56 187
KongXiangyue 0:dc6175686e56 188
KongXiangyue 0:dc6175686e56 189 //-----------
KongXiangyue 0:dc6175686e56 190
KongXiangyue 0:dc6175686e56 191
KongXiangyue 0:dc6175686e56 192 //fclose(mlog);
KongXiangyue 0:dc6175686e56 193 Counter = 0;
KongXiangyue 0:dc6175686e56 194 }// end while (1)
KongXiangyue 0:dc6175686e56 195
KongXiangyue 0:dc6175686e56 196
KongXiangyue 0:dc6175686e56 197 }