need help plotting frequency

[jxa]

for my program i have a sound input that leads to a waveform graph I would like to then use the FFT to plot frequency what I have doesnt seem right if anyones willing to take a look at it? i have labview 8.0

[Coq_Rouge]

You should configure the FFT Express VI to show show the result in dB. Also if you plan to use this in continuous mode. You can not use the Express VI. I tested your VI and it works. Then I do audio testing I start some music on a player. Then I set up the sound input source to be "What U hear"

[jxa]

do you know of a way to display the peak frequency somewhere on the program itself. I am writing the program for school kids 6-12 for a camp I just want to make it as simple as possible. They will basically strike a copper pipe of any length then find the peak frequency do this for several pipes then plot length vs peak frequency setup a bestfit line to get an equation relating th etwo so they can work backwards.

[Coq_Rouge]

I very quickly wiped together this one. Change as you want to. You should avoid Express VIs as they can cause more trouble than good for you.

[jxa]

what are express VIs ; also do you know of a labview function that can allow you to setup few ranges then orgnize the peak frequency into one of the categories.

[jxa]

i need to change the time limit of the data sampled its on a continous loop i need it to sample for like 2-3 seconds how do we change that