Calculate the duration of a pulse with Arduino nano

[adwnis123]

Hello,

I use an Arduino nano. In the digital input 2, I send rectangular pulses, which means I have only two levels: 0 Volts and 5 Volts. I want to measure the duration of a pulse from the time the pulse rises to the time it falls. Of course, Arduino nano cannot support nanosecond accuracy, so I would like to measure the ON (5 Volts) level of the pulse in microseconds level accuracy. How do I realize this? Is there any example code I could follow in order to make this feasible?

 

[KlausST]

Hi,

from hardware side the AVR usually has a "timer capture" feature.

But I don´t know if one can use this with Arduino software, because it usually needs fast software reaction time.

Klaus

 

[andre_luis]

You can attach I/O interrupt to the Arduino code and check how fast it can handle the input; it is a standard feature.

 

[adwnis123]

You can attach I/O interrupt to the Arduino code and check how fast it can handle the input; it is a standard feature.

"and check how fast it can handle the input" -> How do I do that?

 

[andre_luis]

The easy mode, something like that:

• Interrupt, detect low edge,
• Take time (ms)
• Interrupt, detect high edge
• Take time (ms)
• Subtract both measured times
• Check the smaller pulse width able to be detected

The suited mode:

As Klaus mentioned, use timer capture feature to have more resolution.​

 

[adwnis123]

That's why I am interested in example code for Timers/Counter in Arduino, in order to see how it works. Is is very new to me Timers/Counter, I have no experience...