Prev: OT: Oversimplified model
Next: Algorithm implementation
From: Jerry Avins on 23 Apr 2008 18:40
Jerry Avins wrote:
cpptutor2000(a)yahoo.com wrote:
> On Apr 23, 4:18 am, "John E. Hadstate" <jh113...(a)hotmail.com> wrote:
>
>> Even (especially) after reading your later post, I don't
>> understand what you are saying. From your later post, it seems
>> that 7 Hz is your bin resolution, so the first bin corresponds
>> to 7 Hz, the 2nd to 14 Hz, etc. Are you saying that you don't
>> see a spike near bin 71 (500/7)? Perhaps the amplitude of your
>> injected tone is too low compared to the amplitude of your
>> other signal (so the spike is there, it's just lost in the
>> noise). What exactly is the problem?
>
> The problem is, as I mentioned in a posting just before, that when I
> plot the data, I see a long sequence of zeros, about 250 - 300 sample
> points long, before I see the sinusoidal signal. There are a few sharp
> and large spikes at the start, which might be due to DC offset, but I
> do not understand the sequence of zeros. The total sample size of the
> collected data is 2048.

Look to the acquisition software. It's unlikely that there's a startup
transient that large in the hardware, but there may be an offset
between the pointers that write and retrieve the data.

Jerry
--
Engineering is the art of making what you want from things you can get.
�����������������������������������������������������������������������
 | 
Pages: 1
Prev: OT: Oversimplified model
Next: Algorithm implementation