What does the Duration control do in the Tone example?

[LDBM]

I am taking a look at the Tone Example.vi example that ships with LIFA.  The pulse is generated on pin 3 of the Arduino Uno, and this pin is connected to a scope. I set the frequency at 200 Hz, 500 Hz etc... and the square wave on the scope shows up as expected.

However, I do not see any changes on the signal when the "duration" control is changed... what is this control supposed to do ?

Thx.

Laurent

PS: I also altered the vi by only calling the Tone.vi only when a change on either Frequency, or Duration is detected. This drastically reduce the RX .TX operations between the PC and the Arduino

[Kristoff2]

Laurent,

The frequency and duration are passed to the Tone function:

http://arduino.cc/en/Reference/Tone

-Sam K

LIFA Developer

[LDBM]

Yes I can see it is passed to the tone input of the Tone function. But using the

VI example: Tone Example.vi, and looking at the signal on a scope, the duration input

seems to have no effect at all.

L.

[Kevin_F]

Hey Laurent,

The duration input doesn't have an affect in the example because the VI calls the function over and over again in a loop.  If you want the Tone VI to only execute for a certain amount of time you will need to take it outside of the loop. The duration input probably shouldn't be user-settable for this example since it is not going to have an affect.

[LDBM]

Hi Kevin,

As I mentioned earlier Ialtered the vi by only calling the Tone.vi only when a change on either Frequency, or Duration is detected. So in effect the call to done is done once before a parameter change is done by the user, still the duration has no effect. The tone (square signal on my scope) does not end.  I will double-check this, but I am pretty sure of the behavior now.

L.

[Kevin_F]

Hey Laurent,

You are correct there is something goofy going on with the LIFA Tone call.  Ill take a look at it more and see if I can figure out whats going on.

[LDBM]

Ha ! .

By the way, my application actually does not need the pulse to stop. The tone.vi , with its quirk, is a nice easy way to generate an on-going pulse at variable frequencies.

However, fixing it may be useful in general.

L.

[Kevin_F]

Allright I found our error. You can look forward to that fix coming up in the next firmware release.

Thanks for pointing this out.

[LDBM]

By the sound of it, the error in the firmware? not the VI ?

L

[Kevin_F]

The error was in the firmware (order of operations problem with the binary math)