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/SpectrumDisplay.cpp@18:6630d61aeb3c, 2016-02-22 (annotated)
- Committer:
- MikamiUitOpen
- Date:
- Mon Feb 22 13:54:51 2016 +0000
- Revision:
- 18:6630d61aeb3c
- Parent:
- 2:095b360e0f54
19
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
MikamiUitOpen | 0:5c237fdcba23 | 1 | //------------------------------------------------------- |
MikamiUitOpen | 0:5c237fdcba23 | 2 | // Class for display spectrum |
MikamiUitOpen | 0:5c237fdcba23 | 3 | // |
MikamiUitOpen | 2:095b360e0f54 | 4 | // 2015/12/11, Copyright (c) 2015 MIKAMI, Naoki |
MikamiUitOpen | 0:5c237fdcba23 | 5 | //------------------------------------------------------- |
MikamiUitOpen | 0:5c237fdcba23 | 6 | |
MikamiUitOpen | 0:5c237fdcba23 | 7 | #include "SpectrumDisplay.hpp" |
MikamiUitOpen | 0:5c237fdcba23 | 8 | |
MikamiUitOpen | 0:5c237fdcba23 | 9 | namespace Mikami |
MikamiUitOpen | 0:5c237fdcba23 | 10 | { |
MikamiUitOpen | 0:5c237fdcba23 | 11 | SpectrumDisplay::SpectrumDisplay( |
MikamiUitOpen | 0:5c237fdcba23 | 12 | LCD_DISCO_F746NG &lcd, |
MikamiUitOpen | 0:5c237fdcba23 | 13 | int nFft, int x0, int y0, |
MikamiUitOpen | 0:5c237fdcba23 | 14 | float db1, int bin, float maxDb, int fs, |
MikamiUitOpen | 0:5c237fdcba23 | 15 | uint32_t axisColor, uint32_t lineColor, |
MikamiUitOpen | 0:5c237fdcba23 | 16 | uint32_t backColor) |
MikamiUitOpen | 0:5c237fdcba23 | 17 | : N_FFT_(nFft), X0_(x0), Y0_(y0), |
MikamiUitOpen | 0:5c237fdcba23 | 18 | DB1_(db1), BIN_(bin), MAX_DB_(maxDb), |
MikamiUitOpen | 0:5c237fdcba23 | 19 | FS_(fs), AXIS_COLOR_(axisColor), |
MikamiUitOpen | 0:5c237fdcba23 | 20 | LINE_COLOR_(lineColor), BACK_COLOR_(backColor), |
MikamiUitOpen | 0:5c237fdcba23 | 21 | lcd_(lcd) |
MikamiUitOpen | 0:5c237fdcba23 | 22 | { |
MikamiUitOpen | 0:5c237fdcba23 | 23 | AxisX(); |
MikamiUitOpen | 0:5c237fdcba23 | 24 | AxisY(); |
MikamiUitOpen | 0:5c237fdcba23 | 25 | } |
MikamiUitOpen | 0:5c237fdcba23 | 26 | |
MikamiUitOpen | 0:5c237fdcba23 | 27 | void SpectrumDisplay::Draw(float db[]) |
MikamiUitOpen | 0:5c237fdcba23 | 28 | { |
MikamiUitOpen | 2:095b360e0f54 | 29 | const float OFFSET = -50.0f; |
MikamiUitOpen | 0:5c237fdcba23 | 30 | lcd_.SetTextColor(BACK_COLOR_); |
MikamiUitOpen | 0:5c237fdcba23 | 31 | lcd_.FillRect(X0_+1, Y0_-(int)(MAX_DB_*DB1_), |
MikamiUitOpen | 0:5c237fdcba23 | 32 | N_FFT_*BIN_/2, MAX_DB_*DB1_); |
MikamiUitOpen | 0:5c237fdcba23 | 33 | |
MikamiUitOpen | 0:5c237fdcba23 | 34 | float h = ((db[1] + OFFSET) > 0)? db[1] + OFFSET : 0; |
MikamiUitOpen | 0:5c237fdcba23 | 35 | int y1 = Y0_ - (int)(h*DB1_); |
MikamiUitOpen | 0:5c237fdcba23 | 36 | for (int n=1; n<N_FFT_/2; n++) |
MikamiUitOpen | 0:5c237fdcba23 | 37 | { |
MikamiUitOpen | 0:5c237fdcba23 | 38 | float h2 = ((db[n+1] + OFFSET) > 0)? db[n+1] + OFFSET : 0; |
MikamiUitOpen | 0:5c237fdcba23 | 39 | if (h2 > MAX_DB_) h2 = MAX_DB_; |
MikamiUitOpen | 0:5c237fdcba23 | 40 | int y2 = Y0_ - (int)(h2*DB1_); |
MikamiUitOpen | 0:5c237fdcba23 | 41 | lcd_.SetTextColor(LINE_COLOR_); |
MikamiUitOpen | 0:5c237fdcba23 | 42 | lcd_.DrawLine(X0_+n, y1, X0_+n+1, y2); |
MikamiUitOpen | 0:5c237fdcba23 | 43 | y1 = y2; |
MikamiUitOpen | 0:5c237fdcba23 | 44 | } |
MikamiUitOpen | 0:5c237fdcba23 | 45 | lcd_.SetTextColor(AXIS_COLOR_); |
MikamiUitOpen | 0:5c237fdcba23 | 46 | lcd_.DrawLine(X0_, Y0_, X0_+BIN_*N_FFT_/2, Y0_); |
MikamiUitOpen | 0:5c237fdcba23 | 47 | } |
MikamiUitOpen | 0:5c237fdcba23 | 48 | |
MikamiUitOpen | 0:5c237fdcba23 | 49 | // Clear Spectrum |
MikamiUitOpen | 0:5c237fdcba23 | 50 | void SpectrumDisplay::Clear() |
MikamiUitOpen | 0:5c237fdcba23 | 51 | { |
MikamiUitOpen | 0:5c237fdcba23 | 52 | lcd_.SetTextColor(BACK_COLOR_); |
MikamiUitOpen | 0:5c237fdcba23 | 53 | lcd_.FillRect(X0_+1, Y0_-(int)(MAX_DB_*DB1_), |
MikamiUitOpen | 0:5c237fdcba23 | 54 | N_FFT_*BIN_/2, MAX_DB_*DB1_); |
MikamiUitOpen | 0:5c237fdcba23 | 55 | } |
MikamiUitOpen | 0:5c237fdcba23 | 56 | |
MikamiUitOpen | 0:5c237fdcba23 | 57 | // x-axis |
MikamiUitOpen | 0:5c237fdcba23 | 58 | void SpectrumDisplay::AxisX() |
MikamiUitOpen | 0:5c237fdcba23 | 59 | { |
MikamiUitOpen | 0:5c237fdcba23 | 60 | lcd_.SetFont(&Font12); |
MikamiUitOpen | 0:5c237fdcba23 | 61 | |
MikamiUitOpen | 0:5c237fdcba23 | 62 | lcd_.SetTextColor(AXIS_COLOR_); |
MikamiUitOpen | 0:5c237fdcba23 | 63 | lcd_.DrawLine(X0_, Y0_, X0_+BIN_*N_FFT_/2, Y0_); |
MikamiUitOpen | 0:5c237fdcba23 | 64 | float dx = BIN_*(N_FFT_*1000.0f)/(float)FS_; |
MikamiUitOpen | 0:5c237fdcba23 | 65 | for (int n=0; n<=(FS_/1000)/2; n++) |
MikamiUitOpen | 0:5c237fdcba23 | 66 | { |
MikamiUitOpen | 0:5c237fdcba23 | 67 | int xTick = X0_ + (int)(dx*n + 0.5f); |
MikamiUitOpen | 0:5c237fdcba23 | 68 | char s[5]; |
MikamiUitOpen | 0:5c237fdcba23 | 69 | sprintf(s, "%d", n); |
MikamiUitOpen | 0:5c237fdcba23 | 70 | DrawString(xTick-3, Y0_+10, s); |
MikamiUitOpen | 0:5c237fdcba23 | 71 | lcd_.DrawLine(xTick, Y0_, xTick, Y0_+5); |
MikamiUitOpen | 0:5c237fdcba23 | 72 | } |
MikamiUitOpen | 0:5c237fdcba23 | 73 | DrawString(X0_+74, Y0_+24, "Frequency [kHz]"); |
MikamiUitOpen | 0:5c237fdcba23 | 74 | } |
MikamiUitOpen | 0:5c237fdcba23 | 75 | |
MikamiUitOpen | 0:5c237fdcba23 | 76 | // y-axis |
MikamiUitOpen | 0:5c237fdcba23 | 77 | void SpectrumDisplay::AxisY() |
MikamiUitOpen | 0:5c237fdcba23 | 78 | { |
MikamiUitOpen | 0:5c237fdcba23 | 79 | lcd_.SetFont(&Font12); |
MikamiUitOpen | 0:5c237fdcba23 | 80 | |
MikamiUitOpen | 0:5c237fdcba23 | 81 | lcd_.SetTextColor(AXIS_COLOR_); |
MikamiUitOpen | 0:5c237fdcba23 | 82 | lcd_.DrawLine(X0_, Y0_+5, X0_, Y0_-(int)(MAX_DB_*DB1_)); |
MikamiUitOpen | 0:5c237fdcba23 | 83 | for (int n=0; n<=(int)MAX_DB_; n+=20) |
MikamiUitOpen | 0:5c237fdcba23 | 84 | { |
MikamiUitOpen | 0:5c237fdcba23 | 85 | int yTick = Y0_-(int)(DB1_*n); |
MikamiUitOpen | 0:5c237fdcba23 | 86 | char s[5]; |
MikamiUitOpen | 0:5c237fdcba23 | 87 | sprintf(s, "%3d", n); |
MikamiUitOpen | 0:5c237fdcba23 | 88 | DrawString(X0_-30, yTick-5, s); |
MikamiUitOpen | 0:5c237fdcba23 | 89 | lcd_.DrawLine(X0_-5, yTick, X0_, yTick); |
MikamiUitOpen | 0:5c237fdcba23 | 90 | } |
MikamiUitOpen | 0:5c237fdcba23 | 91 | DrawString(X0_-27, Y0_-(int)(DB1_*MAX_DB_)-18, "[dB]"); |
MikamiUitOpen | 0:5c237fdcba23 | 92 | } |
MikamiUitOpen | 0:5c237fdcba23 | 93 | } |