Surpressing 60 Hz noise.
Kyle D. Wesson, Robert M. Ochshorn, Bruce R. Land,
Journal of Neuroscience Methods 185 (2009) 50–55
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The microcontroller requires a C code to be loaded (WinAVR GCC). The code is described in detail in the paper and at a website.
The complete Schematic in ExpressPCB format. Click on image below for more detail. 
The Board layout in ExpressPCB format. Click on image below for more detail. 
The timer2 interruppt rate sets the sample frequency, which in trun is set by the value of TCCR2
Dear Prof. Land,
Is there an easy way to adapt the software to 50Hz cancellation? Could the filter length be simply changed from 8 to 10 giving a window length of 48.8Hz (i.e. 488Hz/10)?
Thanks.
I used fixed point because the AVR is not fast enough to do floating point at the required rate.
Hi, 50hz in europe is the enemy :)
I'm assuming you convert from float point to fixed point simply becasue the MC cannot do float? or is that becasue the LMS filter is working that way ?
I'm trying to learn how to add (mix) audio samples in DSP without loosing headroom in the mix but I think I will stay in float point.
no idea if there is any advantage over fixed point! just started trying to code with a DSP since there are no IC's around that will mix multichannel audio with flexible routing options. wish I could just do this in arduino.
tearing my hair out trying to learn TI's MATHLIB library for DSP.
Bruce Land
Ted Yapo
SimonXi
agp.cooper
peter jansen
Sorry for the stupid question, I am new to AVR programming and to the WinAVR. Could you please point me to the line in the code referring to the sampling frequency? I did not find it in the code. Also, when the LED is supposed to blink? Mine is glowing constantly. Thanks.