Nucleo F401REでFM音源を実装するやつ 外部DACとオペアンプを利用 現在はMCP4922とNJM2737
Dependencies: AOTTrigon I2CEEPROM MCP4922 AQM0802A mbed
Fork of NuMidi401 by
NuFM401
Nucleo F401用の自作ソフトウェアMIDI音源
概要
だいたいそんなもんです。
特徴
- ブレッドボードの上で組める程度には簡単な回路構成
- 外部のDACにMCP4922を採用
- 念のためのボルテージフォロアとしてNJM2737Dを採用
- バンク用EEPROMに24FC1025を採用
- シリアル経由でMIDIデータを受信することで操作
補足
シリアル <=> MIDI のドライバにはHairless-MIDISerialをオススメします。 仮想MIDIケーブルはとりあえずMIDI Yokeで。
Operator.cpp@9:12a54d2ea8fc, 2014-12-29 (annotated)
- Committer:
- kb10uy
- Date:
- Mon Dec 29 02:42:03 2014 +0000
- Revision:
- 9:12a54d2ea8fc
- Parent:
- 7:439c57c20593
- Child:
- 10:0ffdefe75566
??????????
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
kb10uy | 7:439c57c20593 | 1 | #include "Operator.h" |
kb10uy | 7:439c57c20593 | 2 | |
kb10uy | 7:439c57c20593 | 3 | static const float pi2 = 6.283185307179586476925286766559f; |
kb10uy | 7:439c57c20593 | 4 | |
kb10uy | 9:12a54d2ea8fc | 5 | FMOperator::FMOperator(Timer *tm, AOTTrigon *t) |
kb10uy | 7:439c57c20593 | 6 | { |
kb10uy | 7:439c57c20593 | 7 | attack = 0.0f; |
kb10uy | 7:439c57c20593 | 8 | delay = 0.0f; |
kb10uy | 7:439c57c20593 | 9 | sustain = 0.0f; |
kb10uy | 7:439c57c20593 | 10 | sustainRate = 1.0f; |
kb10uy | 7:439c57c20593 | 11 | release = 0.0f; |
kb10uy | 7:439c57c20593 | 12 | |
kb10uy | 7:439c57c20593 | 13 | frequencyMultiple = 1.0f; |
kb10uy | 7:439c57c20593 | 14 | totalLevel = 1.0f; |
kb10uy | 7:439c57c20593 | 15 | |
kb10uy | 9:12a54d2ea8fc | 16 | tri = t; |
kb10uy | 7:439c57c20593 | 17 | master = tm; |
kb10uy | 7:439c57c20593 | 18 | startTime = 0.0; |
kb10uy | 7:439c57c20593 | 19 | releaseTime = 0.0; |
kb10uy | 7:439c57c20593 | 20 | baseFrequency = 1.0f; |
kb10uy | 7:439c57c20593 | 21 | } |
kb10uy | 7:439c57c20593 | 22 | |
kb10uy | 7:439c57c20593 | 23 | float FMOperator::calculate(float fmIn) { |
kb10uy | 7:439c57c20593 | 24 | if (startTime == 0.0) return 0.0f; |
kb10uy | 7:439c57c20593 | 25 | float pos = (pi2 * baseFrequency * frequencyMultiple); |
kb10uy | 9:12a54d2ea8fc | 26 | double nt = (master->read_us() / 1000000.0) - startTime; |
kb10uy | 9:12a54d2ea8fc | 27 | return tri->sin(fmIn + (float)(pos * nt)); |
kb10uy | 7:439c57c20593 | 28 | } |
kb10uy | 7:439c57c20593 | 29 | |
kb10uy | 7:439c57c20593 | 30 | void FMOperator::attackNote(float freq) { |
kb10uy | 7:439c57c20593 | 31 | baseFrequency = freq; |
kb10uy | 9:12a54d2ea8fc | 32 | startTime = master->read_us() / 1000000.0; |
kb10uy | 7:439c57c20593 | 33 | } |
kb10uy | 7:439c57c20593 | 34 | |
kb10uy | 7:439c57c20593 | 35 | void FMOperator::releaseNote() { |
kb10uy | 7:439c57c20593 | 36 | startTime = 0.0; |
kb10uy | 9:12a54d2ea8fc | 37 | releaseTime = master->read_us() / 1000000.0; |
kb10uy | 7:439c57c20593 | 38 | } |