12-17-2008 10:13 AM
12-17-2008 12:06 PM
I could be your developper, but I would be paid for it 😄
For the examples you show, seems more that what you are looking for is just a trigger, as in an oscilloscope. So a trigger is easy to implement, as it is a simple condition: (sample[t-1]< Trigg) &&(sample[t] > Trigg)
You can even use multiple triggers to detect falling edges and rising edges with different trigger level. Then, if you need more accuracy in the peaks, you could use peak detection but only after the trigger fired, or, you can just take the middle point between a falling and a rising edge.
Sorry for the hand-drawed picture, but this would be the final times you would detect if you use triggers and middle points. I would choose middle points because it seems that your signal is "saturating" at some point, having flat "plateau" instead of a peak, which will lead to some difficulties if you try peak detection.
03-04-2009 12:53 PM
I'm having a signal send through NI-DAQ 9172 and then turned into a fft. What i'm trying to accomplish here to find the peaks of the fft and put them through a formula to get a temperature data.
Could anyone help
Thanks
Moe
03-04-2009 12:56 PM
03-04-2009 03:23 PM
03-04-2009 03:50 PM
You could use the fancy LabView peak detection vis or you could build some logic that looks for the Ni value that satisfies the following:
Ni-1 < Ni
Ni > Ni+1
where i = 1...n-1 represents the index values of an array with 0 to n values coded here as capital N.
03-04-2009 05:40 PM
Thanks
One last question. The output that comes out from the peak search is a 2D array and I just want the frequency numbers but don't care about the other values. How would I do that?
03-04-2009 05:51 PM
03-04-2009 06:55 PM