不韋 呂
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UIT2_AllpassReverb
Reverb system using singlae allpass filter for ST Nucleo F401RE.
Diff: main.cpp
- Revision:
- 0:29f3efdfaee8
- Child:
- 1:8f8550f46b19
diff -r 000000000000 -r 29f3efdfaee8 main.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/main.cpp Fri Oct 31 08:12:49 2014 +0000 @@ -0,0 +1,51 @@ +//-------------------------------------------------------------- +// Reverb system using all-pass filter +// 2014/10/31, Copyright (c) 2014 MIKAMI, Naoki +//-------------------------------------------------------------- + +#include "mbed.h" + +#include "ADC_Base.hpp" // for ADC not using interrupt +#include "DAC_MCP4922.hpp" // for DAC MCP4922 +#include "ScfClockTim3.hpp" // for clock supplied to SCF + +using namespace Mikami; + +const int FS_ = 12000; // Sampling frequency: 12 kHz +ADC_Base adc_(A0, FS_); // for AD +DAC_MCP4922 myDac_; // for DA + +const float G_A_ = 0.6f; +const int M1 = 1153; +float unD[M1]; + +DigitalIn sw_(D2, PullDown); + +int main() +{ + ScfClockTim3(500000); // cutoff frequency: 5 kHz + + for (int n=0; n<M1; n++) unD[n] = 0.0f; + int nD = 0; + + while (true) + { + float xn = adc_.Read(); // Read from A0 + //----------------------------------------------- + + float yn; + if (sw_.read() == 1) + { + float un = xn + G_A_*unD[nD]; + yn = -G_A_*un + unD[nD]; + unD[nD++] = un; + if (nD >= M1) nD = 0; + } + else + yn = xn; + + //----------------------------------------------- + myDac_.Write(yn); // Write to DAC + } +} +