Recording and analyzing sound

Hi @Gordon,

I did some tests on point one above, it appeared that when you have:

1) Input at 512Hz with 512 buffer size restricting frequencies between 100Hz and 250Hz.

* Produce 200Hz sine wave audio frequency, then every thing is correctly determined - 200Hz @ XXX

2) Input at 1024Hz with 512 buffer size restricting frequencies between 100Hz and 500Hz.

 * Produce 200Hz sine wave audio frequency, then you have - 100Hz @ XXX as buffer is received twice per second
 * Produce 400Hz sine wave audio frequency, then you have - 200Hz @ XXX as buffer is received twice per second

How can the correct frequency be determined from point 2 above ?