Signal Conditioning
LabVIEW and Arduino, Square Wave
Hello everyone.
I wrote the same post in the 'LabVIEW' section, but im in a bit of a hurry, I didnt get any responses, so I would re-post in this section, if i'm not supposed to do this, let me know and i'll erase the other post.
So I'm trying to implement an acquisiton system with Arduino UNO and LabVIEW. I've design an interface were you can introduce the acquisition speed and the number of samples, and with a button display de data on a graph and also save the data in a spreadsheet. I'm new to this topic of signal acquisition.
Interface
My first aproach was to use LINX, but i couldn't make it work, So i decided to use LIFA(I know it was been discontinued, so i use Arduino 1.8.5 to avoid problems with the Frimware), since LIFA has Analog and Continuous sampling VI's.
For testing purpouses i'm using (In real life) and LM555 with a low pass filter. The circuit produces a 1HZ (approximately) square signal.(The circuit example below,).
So everything it's working BUT, when im acquiring the signal, the display, the frequency doesn't match with the acquiring signal im testing (1HZ). Also i have some noise when im not acquiring anything. I tried to change the frequency of the 555 to something higher (500HZ)and it doesnt seem to resolve the problem.
the frequency doesnt match
Noise
The signal im proccesing has to be a lower to 8.9KHz, because that's the max acquisition range that my arduino can handle.
My questions are: What i am doing wrong?, Is there something really obvious that im passing?, Is Arduino the problem?, Should i use VISA instead?. I also tested in another arduino nano that i have, and still the problem is there.
I did 2 different VI's, one using the continuous sampling function, and the other one using the finite analog sample(this ones is the one that has better results in my opinion).
I've alredy browse on all the NI comunity and i couldnt find anything similar my problem, also i've seen the examples that LIFA has, and also in those i still had the problem with the frequency.
And my final note, Any suggestion or advice is helpfull. My native language is Spanish, so i apologize if there´s something misspelled.
Kudos to everyone.
