Finished hopefully

buttons.c

@@ -4,22 +4,21 @@
 #include <pico/types.h>
 #include "hardware/gpio.h"
 
-void handle_vco_change(void) {
-	static bool btn_prev = false;
+void check_button_change(uint pin, bool* btn_state) {
+	static bool btn_prev[32] = { false };
+	bool btn_now = gpio_get(pin);
+	if (btn_now && !btn_prev[pin]) *btn_state = !*btn_state;
+	btn_prev[pin] = btn_now;
+}
 
-	bool btn_now = gpio_get(VCO_BUTTON);
-	if (btn_now && !btn_prev) {
+void update_buttons() {
+	check_button_change(QUANT_BUTTON, &state.quant_enabled);
+	check_button_change(AMEN_BUTTON, &state.amen_enabled);
+
+	bool vco_change;
+	check_button_change(VCO_BUTTON, &vco_change);
+	if (vco_change) {
 		if (state.vco_mode == VCO_SAW) state.vco_mode = VCO_SINE;
 		otherwise state.vco_mode++;  
 	}
 }
-
-void update_button(uint pin, bool *button_state) {
-	if(gpio_get(pin) != *button_state) *button_state = !*button_state;
-}
-
-void update_buttons() {
-	update_button(QUANT_BUTTON, &state.quant_enabled);
-	update_button(AMEN_BUTTON, &state.amen_enabled);
-	handle_vco_change();
-}

buttons.h

@@ -1,7 +1,5 @@
 #pragma once
 #include <pico/types.h>
 
-void handle_vco_change(uint gpio, uint32_t events);
-void update_button(uint pin, bool *button_state);
 void update_buttons();
 

const.h

@@ -37,6 +37,8 @@
 #define REVERB_AMOUNT_MIN   0.0f
 #define REVERB_AMOUNT_MAX   1.0f
 
+#define AMEN_BPM	85.0f
+#define AMEN_BARS	4.0f
 
 #define otherwise else
 

main.c

@@ -68,8 +68,7 @@ void core1_main(void) {
 	while (1) {
 		update_buttons();
 		update_inputs();
-		//printf("vco_mode: %d, quant_enabled: %d amen_enabled: %d\n", state.vco_mode,state.quant_enabled,state.amen_enabled);
-		//printf("clock_bpm: %f\n",state.clock_bpm);
+		printf("Sample: %f\n", state.dbg_sample);
 		sleep_ms(1);
 	}
 }
@@ -78,6 +77,6 @@ __attribute__((noreturn))
 int main() {
 	init_all();
 	multicore_launch_core1(core1_main);
-	while (1) {}
+	while (1);
 }
 

pwm.c

@@ -1,8 +1,8 @@
 #include <hardware/pwm.h>
 #include <pico/types.h>
-#include <stdio.h>
 
 #include "const.h"
+#include "state.h"
 #include "synth.h"
 
 #include "pwm.h"
@@ -15,7 +15,7 @@ void pwm_isr(void) {
 	pwm_clear_irq(slice);
 
 	float sample = get_sample();
-	printf("sample: %f\n", sample);
+	state.dbg_sample = sample;
 
 	uint16_t level = (uint16_t)((sample + 1.0f) * 0.5f * 3400.0f);
 	pwm_set_chan_level(slice, chan, level);

state.h

@@ -23,6 +23,8 @@ typedef struct {
 	vco_mode_t	vco_mode;
 	bool		quant_enabled;
 	bool		amen_enabled;
+
+	float dbg_sample;
 } state_t;
 
 extern state_t state;

synth.cc

@@ -1,8 +1,9 @@
 #include <math.h>
 #include <stdint.h>
+
+#include "daisysp.h"
 #include "state.h"
 #include "const.h"
-#include "daisysp.h"
 #include "vco.h"
 #include "dsp.h"
 
@@ -15,11 +16,19 @@ Svf filter;
 AdEnv vco_env;
 AdEnv filter_env;
 
-// TODO: Reverb
+DelayLine<float, COMB0_SIZE> comb0;
+DelayLine<float, COMB1_SIZE> comb1;
+DelayLine<float, COMB2_SIZE> comb2;
+DelayLine<float, COMB3_SIZE> comb3;
+DelayLine<float, AP0_SIZE> ap0;
+DelayLine<float, AP1_SIZE> ap1;
 
 float clock_phase = 0.0f;
 bool clock_trig = false;
 
+float amen_phase = 0.0f;
+float amen_length = 0.0f;
+
 static inline auto vco_mode_to_daisy(vco_mode_t mode) {
 	switch (mode) {
 	case VCO_SQUARE:   return daisysp::Oscillator::WAVE_SQUARE;
@@ -37,7 +46,7 @@ static inline float pot_to_time(float v, float min, float max) { return min * po
 static inline float quantize(float freq, float temp) {
 	float midi = temp * log2f(freq / 440.0f) + 69.0f;
 	float note = roundf(midi);
-	return 440.0f * powf(2.0f, (midi - 69.0f) / temp);
+	return 440.0f * powf(2.0f, (note - 69.0f) / temp);
 }
 
 static inline float low_pass(float in, float* z, float coeff) {
@@ -45,11 +54,54 @@ static inline float low_pass(float in, float* z, float coeff) {
 	return *z;
 }
 
+float reverb(float in, float amount) {
+	static float damp0 = 0.0f, damp1 = 0.0f, damp2 = 0.0f, damp3 = 0.0f;
+	float feedback = 0.84f;
+	float damp = 0.3f;
+
+	float c0 = comb0.Read(); low_pass(in + c0 * feedback, &damp0, damp); comb0.Write(damp0);
+	float c1 = comb1.Read(); low_pass(in + c1 * feedback, &damp1, damp); comb1.Write(damp1);
+	float c2 = comb2.Read(); low_pass(in + c2 * feedback, &damp2, damp); comb2.Write(damp2);
+	float c3 = comb3.Read(); low_pass(in + c3 * feedback, &damp3, damp); comb3.Write(damp3);
+
+	float wet = (c0 + c1 + c2 + c3) * 0.25f;
+
+	const float g = 0.7f;
+	float a0r = ap0.Read();
+	float a0in = wet + (-g * a0r);
+	ap0.Write(a0in);
+	wet = a0r + g * a0in;
+
+	float a1r = ap1.Read();
+	float a1in = wet + (-g * a1r);
+	ap1.Write(a1in);
+	wet = a1r + g * a1in;
+
+	return in + amount * (wet - in);
+}
+
+#include "amenbreak.h"
+
+float amenbreak(float beat_samples, float playback_rate) {
+	amen_length = beat_samples * 4.0f * AMEN_BARS;
+
+	uint32_t idx0 = (uint32_t)amen_phase % amen_sample_count;
+	uint32_t idx1 = (idx0 + 1) % amen_sample_count;
+	float    frac = amen_phase - floorf(amen_phase);
+	float    s0   = amen_samples[idx0] * (1.0f / 32768.0f);
+	float    s1   = amen_samples[idx1] * (1.0f / 32768.0f);
+	float amen_out = s0 + frac * (s1 - s0);
+
+	amen_phase += playback_rate;
+	if (amen_phase >= amen_length) amen_phase -= amen_length;
+	return amen_out;
+}
+
 void synth_init(void) {
 	osc.Init(SAMPLE_RATE);
-	osc.SetWaveform(vco_mode_to_daisy(VCO_SINE));
+	osc.SetWaveform(vco_mode_to_daisy(VCO_SAW));
 	osc.SetFreq(440.0f);
-	osc.SetAmp(1.0f);
+	osc.SetAmp(2.0f);
 
 	filter.Init(SAMPLE_RATE);
 	filter.SetFreq(2000.0f);
@@ -57,7 +109,7 @@ void synth_init(void) {
 
 	vco_env.Init(SAMPLE_RATE);
 	vco_env.SetTime(ADENV_SEG_ATTACK, 0.01f);
-	vco_env.SetTime(ADENV_SEG_DECAY, 0.5f);
+	vco_env.SetTime(ADENV_SEG_DECAY, 0.8f);
 	vco_env.SetMin(0.0f);
 	vco_env.SetMax(1.0f);
 
@@ -67,17 +119,22 @@ void synth_init(void) {
 	filter_env.SetMin(0.0f);
 	filter_env.SetMax(1.0f);
 
+	state.clock_bpm = 0.2f;
+
 	clock_phase = 0.0f;
 	clock_trig = false;
+
+	amen_phase = 0.0f;
+	state.amen_enabled = true;
+	state.reverb_amount = 1.0;
 }
 
 float get_sample(void) {
-	return osc.Process();
-}
+	float bpm = BPM_MIN + state.clock_bpm * (BPM_MAX - BPM_MIN);
+	float beat_samples = SAMPLE_RATE * 60.0f / bpm;
+	float playback_rate = bpm / AMEN_BPM;
 
-float _get_sample(void) {
-	float bps = state.clock_bpm / 60.0f;
-	float clock_inc = bps / SAMPLE_RATE;
+	float clock_inc = bpm / 60.0f / SAMPLE_RATE;
 	clock_phase += clock_inc;
 	clock_trig = false;
 	if (clock_phase >= 1.0f) {
@@ -118,7 +175,12 @@ float _get_sample(void) {
 
 	float vca_out = filtered * vco_env_out * state.vco_volume;
 
-	float mix = vca_out;
+	float reverb_out = vca_out; //reverb(vca_out, state.reverb_amount);
+
+	float amen_out = 0.0f;
+	if (state.amen_enabled) amen_out = amenbreak(beat_samples, playback_rate);
+
+	float mix = reverb_out + amen_out;
 	mix = fclamp(mix, -1.0f, 1.0f);
 
 	return mix;

synth.h

@@ -1,5 +1,12 @@
 #pragma once
 
+#define COMB0_SIZE 1103
+#define COMB1_SIZE 1361
+#define COMB2_SIZE 1499
+#define COMB3_SIZE 1693
+#define AP0_SIZE   131
+#define AP1_SIZE   43
+
 #ifdef __cplusplus
 extern "C" {
 #endif