Determining time elapsed in between two successive pulses of a signal

I have a voltage signal from a rotary encoder which gives 1 pulse (4.5v) per revolution. I need to calculate the time elapsed between two successive peaks to get the speed of rotation. Can someone guide me please. My code is attached below. Thanks in advance.

a = arduino;

for i=1:inf
tic;
encoder_signal(i)= readVoltage(a, 'A2');

figure(1);
plot(encoder_signal); 
ylabel('Encoder signal');

hold on;
pause(0.001);

if encoder_signal == 4.5;
 x(i) = toc;
 Engine_RPM (i) = (1/x)*60 ;
 
end

end

[Pat Gipper]

How likely is it that the voltage is going to be exactly 4.5 Volts? I would think that you should trigger on the value exceeding a good threshold value (e.g. encoder_signal > 4).

Answer 1

[Pat Gipper]

I updated your code a bit and fed in an artificial signal. It works but has a slight error due to loop delays running on my computer. You may need to adjust the threshold from 4.5 V depending on your actual encoder signal. If there is a lot of noise then the edge trigger would need hysteresis added to prevent double triggering.

[Senal Perera]

Thank you so much Pat!!! It works.

[Pat Gipper]

No problem Senal. I hadn't tried TicToc before, so it was a good learning experience.