How can i measure the time between two successive rising edges ,using digital input ..

Hello
I'm trying to measure the time in seconds between each two successive rising edges on a digital input .
Till now I have managed to detect the rising edge ,increment a counter with each rising edge ,and snap the time at which the rising edge happenned
all I need now is to subtract the current rising edge time from the previous rising edge time in order to calculate (T) which can be 1/frequency and display it in realtime to the user.
but I don't know how to do this
Can somebody please help me !!!
note: the time that I'm measuring ranges between 200 ms - 2 seconds
Solved!
Go to Solution.
Attachments:
Counter without time.vi ‏11 KB

Cheers for that. It's always a good idea to post your SubVIs as well - the problem could be in one of those.
To help you out:
You already know how to use shift registers so why not use one again for time? Create a new shift register for the time then simply compare the "rising edge time" to the the previous time stored in the shift register and then write the new time to the shift register.
Just a few other pointers:
1. You'll want to initialise your shift registers ie wire a constant to the left hand register outside of the loop. This will cause the register to be reset each time the program is run. This is so that your counter will start from zero each time you run your code.
2. You don't need to use the "greater than?" compare function with boolean as they can only be true or false (1 or 0)! The "Equal?" function is what you should use here.
3. Lastly, it's a small thing but you can use the same tunnel that feeds into a case structure in each of the cases - no need to create two tunnels for the true and false cases, use the same one.
-CC
"If anyone needs me, I'll be in the Angry Dome!"

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How can I measure the time between each two successive rising edges ,using Digital Input ?

Hello
I'm trying two measure the time in seconds between each two successive rising edges on a digital input .
Till now I have managed to detect the rising edge ,increment a counter with each rising edge ,and snap the time at which the rising edge happenned
all I need now is to subtract the current rising edge time from the previous rising edge time in order to calculate (T) which can be 1/frequency and display it in realtime to the user.
but I don't know how to do this
Can somebody please help me !!!
Solved!
Go to Solution.
Attachments:
Counter without time.vi ‏11 KB

Woah!
Sorry Apok, but your code is becoming way too complicated/messy. I don't think that all of those shift registers or boolean conversion/operators are needed at all.
If you want to measure the timing between two button presses then this is a different (much less complicated) way. It simply records the timing of the button press into a shift register then compares the two.
Spoiler (Highlight to read)
Of course this is a very quick and basic solution just to show you that it can be much simpler than you are making it (remember to use the mechanical actions of the buttons to get the behaviour you want).
A better way would be to use an event structure looking at value changes of the buttons to determine the timings between clicks.
-CC
"If anyone needs me, I'll be in the Angry Dome!"
Attachments:
Time between clicks.vi ‏9 KB

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How can i measure the time between two successive rising edges ,using digital input ..

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