Næþ'n Lasseter
/
GraphicEqFFT
A Graphic Equaliser using 2 Analog inputs and an Fast Fourier Transform
Diff: main.cpp
- Revision:
- 0:b771a5301e43
diff -r 000000000000 -r b771a5301e43 main.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/main.cpp Thu Mar 18 15:15:33 2010 +0000 @@ -0,0 +1,71 @@ +/* + * This is my code. It takes 16 samples of the analog in pins and writes the values back to the serial port. + * Nathan Lasseter 2010 + */ + +#include "mbed.h" +#include "TextLCD.h" + +extern void fft(float inarr[16], float outarr[16]); //look for fft at link not compile time + +//Serial pc(USBTX,USBRX); ///dev/ttyACM0 is locked on university pc's +Serial pc(p9,p10); //So I use /dev/ttyS0 instead +BusOut bargraph(p21,p22,p23,p24,p25,p26,p27,p28,p29,p30); //Dot matrix bargraphs horizontal bus +BusOut graphs(p11,p12,p13,p14,p15,p16,p17,p18); //Dot matrix bargraphs vertical bus +AnalogIn left(p19); //Left channel input +AnalogIn right(p20); //Right channel input + +void outputmatrix(float avg, int which) { //This is the simple dot matrix driver. + switch (which) { //Select a bargraph + case 8: graphs = 0xFF; //8: off + case 0: graphs = 0xFE; //0-7 are right to left. They turn on a bargraph by going low. + case 1: graphs = 0xFC; + case 2: graphs = 0xF8; + case 3: graphs = 0xF0; + case 4: graphs = 0xE0; + case 5: graphs = 0xC0; + case 6: graphs = 0x80; + case 7: graphs = 0x00; + } + if (avg > 0.9) { bargraph=0x3FF; return; } //Same principle, but set a value on the graph. + if (avg > 0.8) { bargraph=0x1FF; return; } + if (avg > 0.7) { bargraph=0x0FF; return; } + if (avg > 0.6) { bargraph=0x07F; return; } + if (avg > 0.5) { bargraph=0x03F; return; } + if (avg > 0.4) { bargraph=0x01F; return; } + if (avg > 0.3) { bargraph=0x00F; return; } + if (avg > 0.2) { bargraph=0x007; return; } + if (avg > 0.1) { bargraph=0x003; return; } + if (avg > 0.0) { bargraph=0x001; return; } + bargraph=0x000; //Default to all off +} + +int main() { //Main code + while(1) { + int i; +/* float leftin[16], leftout[16]; //While technically it can support 16 bands over each of 2 channels... + float rightin[16], rightout[16]; + for(i=0;i<16;i++) leftin[i] = left; + for(i=0;i<16;i++) rightin[i] = right; + fft(leftin, leftout); + fft(rightin, rightout); */ + float in[16], out[16], avg[8]; //I only use 8 on one channel + for(i=0;i<16;i++) in[i] = (left + right) / 2; //So I average the two + fft(in, out); + for(i=0;i<8;i++) avg[i] = (out[2*i] + out[(2*i)+1]) / 2; //And then average pairs of bands +/* pc.printf("%f %f %f %f %f %f %f %f\t%f %f %f %f %f %f %f %f\n", + leftout[0], leftout[1], leftout[2], leftout[3], + leftout[4], leftout[5], leftout[6], leftout[7], + leftout[8], leftout[9], leftout[10], leftout[11], + leftout[12], leftout[13], leftout[14], leftout[15]); + pc.printf("%f %f %f %f %f %f %f %f\t%f %f %f %f %f %f %f %f\n\n", + rightout[0], rightout[1], rightout[2], rightout[3], + rightout[4], rightout[5], rightout[6], rightout[7], + rightout[8], rightout[9], rightout[10], rightout[11], + rightout[12], rightout[13], rightout[14], rightout[15]); */ + pc.printf("%f %f %f %f\t%f %f %f %f\r\n", //Then print the values to the uart + avg[0], avg[1], avg[2], avg[3], + avg[4], avg[5], avg[6], avg[7]); + for(i=0;i<8;i++) outputmatrix(avg[i], i); //And display on the bargrpahs + } +} \ No newline at end of file