Erik van de Coevering
Latest version of my quadcopter controller with an LPC1768 and MPU9250.
Currently running on a custom PCB with 30.5 x 30.5mm mounts. There are also 2 PC apps that go with the software; one to set up the PID controller and one to balance the motors and props. If anyone is interested, send me a message and I'll upload them.
Diff: Filters/LPfilter.cpp
- Revision:
- 7:d86c41443f6d
- Parent:
- 4:fab65ad01ab4
--- a/Filters/LPfilter.cpp Sat Jul 14 10:30:20 2018 +0000
+++ b/Filters/LPfilter.cpp Tue Jul 17 14:56:05 2018 +0000
@@ -1,9 +1,9 @@
// Coded by Erik van de Coevering
-// DSP-style low-pass filters designed with Matlab's FDAtool.
+// DSP-style low-pass IIR filters designed with Matlab's FDAtool.
// For information on how to implement these filters, check this pdf: http://spinlab.wpi.edu/courses/ece4703_2009/how_to_interpret_matlab_dfii_sos.pdf
#include "LPfilter.h"
-
+/*
float LPfilter::run(float input) {
filterbuffer[2] = filterbuffer[1];
filterbuffer[1] = filterbuffer[0];
@@ -42,4 +42,33 @@
out = filterbuffer2[0] + filterbuffer2[1]*2.0f + filterbuffer2[2];
return out;
}
+*/
+//8th order IIR filter, with Fs = 1500Hz and Fc = 45Hz
+float LPfilter8::run(float input) {
+ filterbuffer1[2] = filterbuffer1[1];
+ filterbuffer1[1] = filterbuffer1[0];
+ filterbuffer1[0] = input*0.008544036438708 + filterbuffer1[1]*1.895289756537 + filterbuffer1[2]*-0.9294659022914;
+
+ out_temp1 = filterbuffer1[0] + filterbuffer1[1]*2.0f + filterbuffer1[2];
+
+ filterbuffer2[2] = filterbuffer2[1];
+ filterbuffer2[1] = filterbuffer2[0];
+ filterbuffer2[0] = out_temp1*0.008021326615853 + filterbuffer2[1]*1.779339107215 + filterbuffer2[2]*-0.811424413678;
+
+ out_temp2 = filterbuffer2[0] + filterbuffer2[1]*2.0f + filterbuffer2[2];
+
+ filterbuffer3[2] = filterbuffer3[1];
+ filterbuffer3[1] = filterbuffer3[0];
+ filterbuffer3[0] = out_temp2*0.007662537043122 + filterbuffer3[1]*1.699750237618 + filterbuffer3[2]*-0.7304003857905;
+
+ out_temp3 = filterbuffer3[0] + filterbuffer3[1]*2.0f + filterbuffer3[2];
+
+ filterbuffer4[2] = filterbuffer4[1];
+ filterbuffer4[1] = filterbuffer4[0];
+ filterbuffer4[0] = out_temp3*0.007481430998498 + filterbuffer4[1]*1.659576201179 + filterbuffer4[2]*-0.6895019251732;
+
+ out = filterbuffer4[0] + filterbuffer4[1]*2.0f + filterbuffer4[2];
+
+ return out;
+}