不韋 呂 / Mbed 2 deprecated F746_RealtimeSpectrumAnalyzer

Realtime spectrum analyzer. Using FFT, linear prediction, or cepstrum smoothing. Version using MEMS microphone and CODEC, named "F746_RealtimeSpectrumAnalyzer_MEMS_Mic" is registered. リアルタイム スペクトル解析器．解析の手法：FFT，線形予測法，ケプストラムによる平滑化の３種類．このプログラムの説明は，CQ出版社のインターフェース誌，2016年4月号に掲載．外付けのマイクまたは他の信号源等を A0 に接続する．線形予測法，ケプストラムは，スペクトル解析の対象を音声信号に想定してパラメータを設定している．MEMS マイクと CODEC を使ったバージョンを "F746_RealtimeSpectrumAnalyzer_MEMS_Mic" として登録．

Dependencies:   BSP_DISCO_F746NG BUTTON_GROUP LCD_DISCO_F746NG TS_DISCO_F746NG UIT_FFT_Real mbed

MyClasses/Sampler.cpp@6:b27ef8d98edc, 2015-12-18 (annotated)

Committer:
MikamiUitOpen
Date:
Fri Dec 18 10:09:31 2015 +0000
Revision:
6:b27ef8d98edc
Parent:
5:98ec9dd54144
Child:
7:6598a9b70e5a
7

Who changed what in which revision?

UserRevisionLine numberNew contents of line
MikamiUitOpen 2:095b360e0f54 1 //-----------------------------------------------------------
MikamiUitOpen 2:095b360e0f54 2 // Class for sampling input signal
MikamiUitOpen 2:095b360e0f54 3 //
MikamiUitOpen 6:b27ef8d98edc 4 // 2015/12/18, Copyright (c) 2015 MIKAMI, Naoki
MikamiUitOpen 2:095b360e0f54 5 //-----------------------------------------------------------
MikamiUitOpen 2:095b360e0f54 6
MikamiUitOpen 2:095b360e0f54 7 #include "Sampler.hpp"
MikamiUitOpen 2:095b360e0f54 8
MikamiUitOpen 2:095b360e0f54 9 namespace Mikami
MikamiUitOpen 2:095b360e0f54 10 {
MikamiUitOpen 6:b27ef8d98edc 11 Sampler::Sampler(PinName pin, int fs, int nData,
MikamiUitOpen 6:b27ef8d98edc 12 int16_t* const buffer)
MikamiUitOpen 2:095b360e0f54 13 : TS_(1000000/fs), N_DATA_(nData), aIn_(pin),
MikamiUitOpen 6:b27ef8d98edc 14 buffer_(buffer)
MikamiUitOpen 2:095b360e0f54 15 {
MikamiUitOpen 2:095b360e0f54 16 Set(false);
MikamiUitOpen 2:095b360e0f54 17 Rd[0] = &Sampler::ReadNorm; // inphase
MikamiUitOpen 2:095b360e0f54 18 Rd[1] = &Sampler::ReadInv; // out-of-phase
MikamiUitOpen 2:095b360e0f54 19 sw_ = 0;
MikamiUitOpen 5:98ec9dd54144 20 for (int n=0; n<nData; n++)
MikamiUitOpen 5:98ec9dd54144 21 buffer_[n] = 32767;
MikamiUitOpen 2:095b360e0f54 22 }
MikamiUitOpen 2:095b360e0f54 23
MikamiUitOpen 2:095b360e0f54 24 void Sampler::IntrEnable()
MikamiUitOpen 2:095b360e0f54 25 {
MikamiUitOpen 2:095b360e0f54 26 count_ = 0;
MikamiUitOpen 2:095b360e0f54 27 timer_.attach_us(this, &Sampler::Isr, TS_);
MikamiUitOpen 2:095b360e0f54 28 }
MikamiUitOpen 2:095b360e0f54 29
MikamiUitOpen 2:095b360e0f54 30 void Sampler::Set(bool tf)
MikamiUitOpen 2:095b360e0f54 31 {
MikamiUitOpen 2:095b360e0f54 32 timer_.detach();
MikamiUitOpen 2:095b360e0f54 33 trigger_ = false;
MikamiUitOpen 2:095b360e0f54 34 xnM1_ = 32767;
MikamiUitOpen 2:095b360e0f54 35 filled_ = tf;
MikamiUitOpen 2:095b360e0f54 36 }
MikamiUitOpen 2:095b360e0f54 37
MikamiUitOpen 2:095b360e0f54 38 // Interrupt service routine for Ticker
MikamiUitOpen 2:095b360e0f54 39 void Sampler::Isr()
MikamiUitOpen 2:095b360e0f54 40 {
MikamiUitOpen 2:095b360e0f54 41 if (!trigger_)
MikamiUitOpen 2:095b360e0f54 42 {
MikamiUitOpen 2:095b360e0f54 43 int16_t xn = (this->*Rd[sw_])();
MikamiUitOpen 2:095b360e0f54 44 // Detect rising edge
MikamiUitOpen 2:095b360e0f54 45 if ((xn > (xnM1_+512)) && (xn > 2048))
MikamiUitOpen 2:095b360e0f54 46 trigger_ = true;
MikamiUitOpen 2:095b360e0f54 47 else
MikamiUitOpen 2:095b360e0f54 48 xnM1_ = xn;
MikamiUitOpen 2:095b360e0f54 49 return;
MikamiUitOpen 2:095b360e0f54 50 }
MikamiUitOpen 2:095b360e0f54 51
MikamiUitOpen 2:095b360e0f54 52 buffer_[count_] = (this->*Rd[sw_])(); // Read from A0
MikamiUitOpen 2:095b360e0f54 53
MikamiUitOpen 2:095b360e0f54 54 if (++count_ >= N_DATA_)
MikamiUitOpen 2:095b360e0f54 55 Set(true); // Permits spectrum analysis
MikamiUitOpen 2:095b360e0f54 56 }
MikamiUitOpen 2:095b360e0f54 57 }