Goertzel's Algorithm was recommended in a previous topic. I've found some C code that will get me going really quickly. I was wondering whether the samples have to be centered around zero? Or can they be used directly from an ADC (i.e. range from 0 to 255 or so and be centered about 128?) Thanks, John
Goertzel Algorithm
Started by ●February 13, 2006
Reply by ●February 13, 20062006-02-13
jecottrell@comcast.net wrote:> Goertzel's Algorithm was recommended in a previous topic. I've found > some C code that will get me going really quickly. I was wondering > whether the samples have to be centered around zero? Or can they be > used directly from an ADC (i.e. range from 0 to 255 or so and be > centered about 128?)The offset amounts to a strong DC component. It may make numeric problems -- overflow ans all that -- but it should otherwise not interfere. It's easy to convert offset binary to signed binary. Just subtract half the (maximum + 1) or, what amounts to the same thing, invert the most significant bit. Some ADCs can be set up to invert the MSB internally. jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
Reply by ●February 13, 20062006-02-13