Appendix for Audio Localization Project**new**2004/12/15 10:13:49.399 US/Central2004/12/15 15:37:37.045 US/CentralElizabethGregorylizzardg@rice.eduJosephColejoecole@rice.eduElizabethGregorylizzardg@rice.eduJosephColejoecole@rice.eduappendixbeamformingcodeLM386Dtrigonometric identitiesThis section contains a few important links, the code that we used for the project, and the project executable files.Matlab Codenew_sim2:
function new_sim2(theta_true)
% Values, Vectors, and a Matrix
%theta_true = pi./2;
degree = 32;
c = 346.287; % speed of sound in air
N = 150; % length of the sample buffer
Fs = 48000; % sampling frequency
f = 500; % frequency of sine wave
M = 2; % number of microphones
dist = .1;
t = [0:N-1]./Fs; % time axis
m = (M-1)./2; % array center
x = dist.*[-m:m]; % microphone location on the x axis
omega = 2*pi*f; % commonly used value
theta_test = [1:2:2*degree-1]*pi/(2*degree); % test vector of theta values
%theta_test = pi./2;
divisor = degree/8; % region divisor
length_t = length(theta_test); % length of the delay vector
A = zeros(1,length_t); % initialize A vector
delay_true = x.*cos(theta_true)./c; % actual delay
delay_test = x'*cos(theta_test)./c; % test matrix of delay values
samples = round(2.*delay_test*Fs)./2; % number of samples to shift in testing
index = samples - ones(M,1)*min(samples) + 1;
% Signal Simulation
for j = 1:M
y(j,:) = sin(omega*(t-delay_true(j)));
end
% Region Approximation
for i = [1:length_t]
for j = [1:M]
y_delay(j,:) = y(j,[index(j,i)+50:index(j,i)+100]); %delay y1 by the 1,i value using index
end
z = sum(y_delay);
A(i) = sum(z.^2);
end
aa = find(A == max(A));
region = floor(aa(1)./divisor)
theta_range = [region-1 region]*pi/8;
if(0)
figure
plot(theta_test/pi,A)
end
sim_input3:
function [region,theta_range] = sim_input3(theta_true,degree)
% Values, Vectors, and a Matrix
c = 346.287; % speed of sound in air
N = 150; % length of the sample buffer
Fs = 44100; % sampling frequency
f = 500; % frequency of sine wave
M = 2; % number of microphones
%dist = .32; % distance between microphones
dist = .5;
t = [0:N-1]./Fs; % time axis
m = (M-1)./2; % array center
x = dist.*[-m:m]; % microphone location on the x axis
cutoff = 50; % cutoff frequency of filter
omega = 2*pi*f; % commonly used value
theta_test = [1:2:2*degree-1]*pi/(2*degree); % test vector of theta values
divisor = degree/8; % region divisor
length_t = length(theta_test); % length of the delay vector
A = zeros(1,length_t); % initialize A vector
B = fir1(40,cutoff/Fs,'low'); % lowpass filter
delay_true = x.*cos(theta_true)./c; % actual delay
delay_test = x'*cos(theta_test)./c; % test matrix of delay values
samples = round(2.*delay_test*Fs)./2; % number of samples to shift in testing
index = samples - ones(M,1)*min(samples) + 1;
cos_base = cos(omega*t(1:N));
sin_base = sin(omega*t(1:N));
SNR = 1000;
noise1 = randn(1,N)/SNR;
noise2 = randn(1,N)/SNR;
% Signal Simulation
y1 = sin(omega*(t-delay_true(1))) + noise1;
y2 = sin(omega*(t-delay_true(2))) + noise2;
% Region Approximation
for i = [1:length_t]
y1_sample = y1(index(1,i):index(1,i)+40); %delay y1 by the 1,i value using index
y2_sample = y2(index(2,i):index(2,i)+40);
z = y1_sample + y2_sample;
z_cos = z.*cos_base(1:41);
z_sin = z.*sin_base(1:41);
z_cos_filter = sum(fliplr(z_cos).*B);
z_sin_filter = sum(fliplr(z_sin).*B);
A(i) = z_sin_filter^2 + z_cos_filter^2;
end
% figure
% plot(theta_test,A);
% title(theta_true)
aa = find(A == max(A));
region = floor(aa(1)./divisor);
if(0)
theta_range = [region-1 region]*pi/8;
figure
plot(theta_test/pi,A)
end
C Codeindex.h:
short index[2][32] = {
{0x0001, 0x0001, 0x0001,0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0008, 0x0009, 0x000A, 0x000A, 0x000B, 0x000C, 0x000D, 0x000D, 0x000D, 0x000E, 0x000E},
{0x000E, 0x000E, 0x000D,0x000D, 0x000D, 0x000C, 0x000B, 0x000A, 0x000A, 0x0009, 0x0008, 0x0006, 0x0005, 0x0004, 0x0003, 0x0002, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001}
};
loop_intr_pcm2.c:
> 16);
buffer2[buf_index] = (short)sample;
buf_index++;
if(buf_index == N) {
buf_index = 0;
buf_full = 1;
}
return; //return from interrupt
}
void main()
{
int i;
int j;
int k = 0;
int z, test_amp;
int region;
int out;
int sum = 0;
int max_theta_index = 0;
int max_amplitude = -1;
for(k=0;k> 15;
}
if(test_amp > max_amplitude) {
max_amplitude = test_amp;
max_theta_index = i;
}
}
region = max_theta_index >> 2;
sum -= buffer3[k];
buffer3[k++] = region;
sum += region;
if(k == N2) {
k = 0;
out = sum >> 7;
/*if(out > 3)
out = 0;
else
out = 7;*/
*lights = out << 24;
}
}
}
}]]>
vectors_11.asm:
*Vectors_11.asm Vector file for interrupt-driven program
.ref _c_int12 ;ISR used in C program
.ref _c_int00 ;entry address
.sect "vectors" ;section for vectors
RESET_RST: mvkl .S2 _c_int00,B0 ;lower 16 bits --> B0
mvkh .S2 _c_int00,B0 ;upper 16 bits --> B0
B .S2 B0 ;branch to entry address
NOP ;NOPs for remainder of FP
NOP ;to fill 0x20 Bytes
NOP
NOP
NOP
NMI_RST: .loop 8
NOP ;fill with 8 NOPs
.endloop
RESV1: .loop 8
NOP
.endloop
RESV2: .loop 8
NOP
.endloop
INT4: .loop 8
NOP
.endloop
INT5: .loop 8
NOP
.endloop
INT6: .loop 8
NOP
.endloop
INT7: .loop 8
NOP
.endloop
INT8: .loop 8
NOP
.endloop
INT9: .loop 8
NOP
.endloop
INT10: .loop 8
NOP
.endloop
INT11: .loop 8
NOP
.endloop
INT12: b _c_int12 ;branch to ISR
.loop 7
NOP
.endloop
INT13: .loop 8
NOP
.endloop
INT14: .loop 8
NOP
.endloop
INT15: .loop 8
NOP
.endloop
Project Executable Filesproject.outproject.pafproject.pjt