Simple synthesizer for STM32F401RE/STMstation.
Dependencies: FastPWM mbed-dsp
This is a basic synthesizer to play music on the STM32F401RE Nucleo/STMstation development board:
Please see the API documentation for further details.
Here's a demo of the synthesizer at work in a music composing program on the STMstation. This one is "Miku" by Anamanaguchi.
STMstation_synth.h
- Committer:
- kkado
- Date:
- 2017-07-03
- Revision:
- 0:c5ca205c0a80
- Child:
- 1:db0c24aebb8a
File content as of revision 0:c5ca205c0a80:
#ifndef STMstation_synth_h #define STMstation_synth_h #include "mbed.h" #include "arm_math.h" #include "FastPWM.h" /** Basic synthesizer library for STM32F401RE Nucleo or STMstation P.1 development boards - may work with * other targets, but not tested yet. * * This is a multi-channel synthesizer, with sine, square, triangle, and noise waveform generation. Music is * stored as arrays in flash, but it is possible to use editable arrays in RAM. Standard number of channels is * 5, but additional channels can be added by changing the CHANNELS define. * * Audio signal is output as a PWM signal on PB_0, which MUST be fed into a 1-bit DAC to generate sound! * * Suggested setup: * @code * (PB_0)-----(R1)-----(C2) * | | * (C1) (SPEAKER) * | | * (GND) (GND) * * R1 = 150 Ohms, C1 = 47nF, C2 = 1uF, Speaker = 0.25W, 8 Ohms * @endcode */ #define AUDIO_PIN PB_0 #define CHANNELS 5 //Audio melody struct struct melody{ const uint8_t * notes[CHANNELS]; const uint8_t * durations[CHANNELS]; const uint8_t * AR[CHANNELS]; const uint8_t * vol[CHANNELS]; uint16_t max[CHANNELS]; bool ended[CHANNELS], repeat[CHANNELS]; uint8_t bpm; }; //Audio master struct struct master{ const uint8_t * notes[CHANNELS]; const uint8_t * durations[CHANNELS]; const uint8_t * AR[CHANNELS]; const uint8_t * vol[CHANNELS]; uint16_t index[CHANNELS], max[CHANNELS]; float env[CHANNELS], sineCoef[CHANNELS], vSum, atkSlope[CHANNELS], relSlope[CHANNELS], relOffset[CHANNELS], volCoef[CHANNELS], halfPeriod[CHANNELS], triSlope[CHANNELS], noiseVal[CHANNELS], triVal[CHANNELS]; uint32_t counter[CHANNELS], envAtkEnd[CHANNELS], envRelStart[CHANNELS]; uint8_t val, timbre[CHANNELS], freqIndex[CHANNELS], bpm[CHANNELS]; bool repeat[CHANNELS]; bool* endptr[CHANNELS]; }; class STMstation_synth{ public: STMstation_synth(); void calc_coefs(int i); void calc_vSum2(); void calc_env(); int8_t square(float _halfperiod, uint16_t _counter); void calc_triangle(uint8_t _channel, float _halfperiod, float _trislope, uint32_t _counter); void calc_noise(uint8_t _channel, uint8_t _freq, uint32_t _counter); void calc_val2(); void clear_channel(uint8_t _channel); void stop_track(melody &newMelody); bool check_track(melody &newMelody); void check_end(); void check_start(); void note2(); void play(melody &newMelody, uint8_t refChannel = 0, uint16_t newIndex = 0); const uint16_t FSAMP; const float period; struct master Master; private: Ticker sample; FastPWM tone; }; #endif