fall time of square wave

Hi everyone... I want to know the time that my pulses goes 0 (the red points) what is the best way to do that.

Answer 1

[Azzi Abdelmalek]

If y is your signal

idx=strfind(y,[1 0])

[m b]

Dear Azzi

Thanks for your answer, but it did not work. I wrote sth but I want to know if there is another easy and best way

this is what i wrote

for i=1:length(y);

   z= find ( y==0 );
    end
for i=1:16:length(z);
   zz=z(i)
   hold on
   plot (zz,y(zz),'g*')

end and i got this (red stares)

Answer 2

[Stephen23]

Try this:

N = 200;
% fake data:
vec = ones(1,N);
vec(randperm(N,5)) = 0;
% detect zeros:
idx = diff(vec)<0;
plot(1:N,vec,'-b',find(idx),vec(idx),'r*')

You will also need to decide what happens with leading zeros: I have not taken them into account in this algorithm.

[m b]

Dear stephen, thanks for your answer.

[John BG]

Stephen's answer finds the red dots, but when you write 'know the time that my pulses goes 0 (the red points)' do you mean you want dt1+dt2+dt3+dt4 of the initial signal?

The transitions are not vertical, check the blue arrows.

Do you want to know know much time the signal is stuck on 0?