I am working on a beat detection device, which I received good help from in my earlier question this week.
I am using Open Music Labs FHT library for Arduino to read Analog Input 0 and translate the incoming signal to an frequency spectrum range.
According to the article found at the bottom of the question, the prescaler of the ADC will affect the sample rate which in turn affects the range of frequencies available at the end of the FHT process.
So basically, how do I change the prescaler, and what is the lowest setting of the prescaler?
Altrnatively, where can I find a list of the different prescaler modes?
Goal:
I need to broaden the lower frequency range so that I properly can distinguish the kick from the bassline and other elements of the music. The kick will be the most important factor for the beat detection algorithm.
What I've already tried:
Changed a variable value of the Open Music Labs Arduino sketch from ADCSRA = 0xe5; to ADCSRA = 0xff;
The FHT bin 0 which is the most interesting part for my beat detection device contains all the frequencies between ~12.5 Hz to 166Hz with the ADCSRA value set to 0xe5
while as when setting ADCSRA to 0xff, bin 0 in the FHT contains the frequencies between ~12.3 to 174Hz.
Theres barely any change, not significant at all. It's so small that it can be ignored.
They are mentioning the presacler in the following forum thread: http://www.openmusiclabs.com/forums/viewtopic.php?f=4&t=396&sid=52e689bcc6392ff31e1d8425bd2c6c3e
