Guru
Joined: 30/06/2020
Location: GermanyPosts: 757
| Posted: 06:40pm 03 Feb 2022 |
Thank you lizby for your advice! I am using easyEDA as "software".
I just wanted to post a quick update with my digital filter (there are more to come!)
The filter does work really great, there is no noise at all. The next filter I am planning is to make it more resistant against hand and body movements (high pass filter).
SetTick 10, ekg_interrupt 'samplerate 100Hz
SetPin GP28, AIN
SetPin GP25, DOUT
CLS c
Do
If x>319 Then
x=0
EndIf
Loop
ekg_interrupt:
x=x+1
ekg = Pin(GP28)
a0 = 0.20657128
a1 = 0.21314257
a2 = 0.20657128
b1 = 0.16952595
b2 = 0.09581110
sn_2 = s_n1
s_n1 = s_n
s_n = ekg
g_n2 = g_n1
g_n1 = g_n
g_n = s_n*a0+s_n1*a1+s_n2*a2+g_n1*b1+g_n2*b2
ekg = g_n
Line x,0,x+10,319,1,BF
Line x-1,ekg_alt*100,x,ekg*100,1
ekg_alt = ekg
IReturn
I know the screen draw could be better etc, but I am concetrating right now on the plain filter implementation :)
Edited 2022-02-04 04:43 by Amnesie