clear all
fs=1000  % sample frequency 1000hz
nDFT=128 %128 point sample
t = 0:1/fs:(nDFT)*(1/fs)
x = 3*sin(80*pi*t) + sin(160*pi*t)
subplot(2,1,1)
stem(t,x,'.')
xlabel('t')
ylabel('x(t)')
y=fft(x)
y=fftshift(y)
f=-fs/2:fs/nDFT:fs/2
subplot(2,1,2)
stem(f,abs(y),'.')
xlabel('freq')
saveas(gcf,'ex1.png')
sampled_signal = fopen('sampled_signal.bin','w')
fwrite(sampled_signal,x,'double')
fclose(sampled_signal)