use integer math only for tone generation

dac.hpp

@@ -9,8 +9,8 @@ namespace dac {
 		DDRD = 0xff;
 	}
 	
-	inline void set(float v_f) {
+	inline void set(int v) {
-		PORTD = clamp((int)(v_f * -128) + 127, 0, 255);
+		PORTD = clamp(v, 0, 255);
 	}
 };
 

data.cpp

@@ -0,0 +1,112 @@
+
+#include <Arduino.h>
+#include <SoftwareSerial.h>
+#include <avr/pgmspace.h>
+#include "midi_data.hpp"
+#include "data.hpp"
+
+const int SERIAL_RX = A4;
+const int SERIAL_TX = A5;
+
+enum Mode : uint8_t {
+	none,
+	ready,
+	local,
+	serial,
+	read,
+	jump,
+};
+
+static char buff[64];
+static bool buff_full = false;
+static unsigned buff_at = 0;
+static unsigned address = 0;
+static SoftwareSerial serial_dev(SERIAL_RX, SERIAL_TX);
+static Mode mode = Mode::local;
+
+void data::init() {
+	pinMode(SERIAL_RX, INPUT);
+	pinMode(SERIAL_TX, OUTPUT);
+	serial_dev.begin(57600);
+	serial_dev.listen();
+	serial_dev.write(Mode::ready);
+
+	unsigned long ts_end = millis() + 1000;
+	while(ts_end > millis()) {
+		if(check()) {
+			break;
+		}
+	}
+}
+
+bool data::check() {
+	if(serial_dev.available()) {
+		mode = serial_dev.read();
+		return true;
+	} else {
+		return false;
+	}
+}
+
+void data::jump(unsigned long loc) {
+	switch(mode) {
+	case Mode::local:
+		address = loc;
+		break;
+	case Mode::serial:
+		serial_dev.write(Mode::jump);
+		serial_dev.write(loc >> 24);
+		serial_dev.write(loc >> 16);
+		serial_dev.write(loc >> 8);
+		serial_dev.write(loc);
+		break;
+	}
+}
+
+inline uint8_t proc_len(uint8_t len) {
+	if(address + len >= sizeof(MIDI)) {
+		return sizeof(MIDI) - address;
+	} else {
+		return len;
+	}
+}
+
+static void fill_buffer() {
+	serial_dev.write(Mode::read);
+	serial_dev.write(sizeof(buff));
+	for(int i = 0; i < sizeof(buff); i++) {
+		while(!serial_dev.available()) {}
+		buff[i] = serial_dev.read();
+	}
+	buff_at = 0;
+	buff_full = true;
+}
+
+void data::read(void* data, uint8_t len) {
+	char* bytes = (char*)data;
+	switch(mode) {
+	case Mode::local:
+		len = proc_len(len);
+		memcpy_P(bytes, &MIDI[address], len);
+		address += len;
+		break;
+	case Mode::serial:
+		if(!buff_full) {
+			fill_buffer();
+		}
+		while(sizeof(buff) - buff_at < len) {
+			auto l = sizeof(buff) - buff_at;
+			memcpy(bytes, buff + buff_at, l);
+			bytes += l;
+			len -= l;
+			fill_buffer();
+		}
+		memcpy(bytes, buff + buff_at, len);
+		buff_at += len;
+		break;
+	}
+}
+
+void data::write(const void* data, uint8_t len) {
+}
+

data.hpp

@@ -0,0 +1,12 @@
+
+#pragma once
+
+namespace data {
+	
+	void init();
+	bool check();
+	void jump(unsigned long loc = 0);
+	void read(void* data, uint8_t len);
+	void write(const void* data, uint8_t len);
+};
+

eeprom.cpp

@@ -1,33 +0,0 @@
-
-#include <avr/pgmspace.h>
-#include "midi_data.hpp"
-#include "eeprom.hpp"
-
-static int address = 0;
-
-void eeprom::jump(int loc) {
-	address = loc;
-}
-
-inline size_t proc_len(size_t len) {
-	if(address + len >= sizeof(MIDI)) {
-		return sizeof(MIDI) - address;
-	} else {
-		return len;
-	}
-}
-
-void eeprom::read(void* data, size_t len) {
-	char* bytes = (char*)data;
-	len = proc_len(len);
-	memcpy_P(data, &MIDI[address], len);
-	address += len;
-}
-
-void eeprom::write(const void* data, size_t len) {
-	const char* bytes = (const char*)data;
-	len = proc_len(len);
-	address += len;
-}
-
-

eeprom.hpp

@@ -1,10 +0,0 @@
-
-#pragma once
-
-namespace eeprom {
-	
-	void jump(int loc = 0);
-	void read(void* data, size_t len);
-	void write(const void* data, size_t len);
-};
-

entry.hpp

@@ -42,7 +42,7 @@ namespace entry {
 
 	struct Config {
 		uint32_t us_per_tick;
-		float amplitude;
+		uint8_t amplitude;
 	};
 
 	struct Generic {
@@ -68,7 +68,7 @@ namespace entry {
 		case Type::clear_ts:
 			return 4;
 		case Type::config:
-			return 8;
+			return 5;
 		case Type::stop:
 		default:
 			return 1;

indicator.cpp

@@ -10,10 +10,10 @@ void indicator::init() {
 }
 
 void indicator::update() {
-    float v = 0;
+    unsigned v = 0;
     for(int i = 0; i < tones::active; i++) {
       v += tones::all[i].amplitude;
     }
-    analogWrite(LED_INDICATOR, min((int)(v * 256), 255));
+    analogWrite(LED_INDICATOR, min(v, 255));
 }
 

scheduler.cpp

@@ -2,7 +2,7 @@
 #include <Arduino.h>
 #include "timing.hpp"
 #include "scheduler.hpp"
-#include "eeprom.hpp"
+#include "data.hpp"
 #include "entry.hpp"
 #include "tones.hpp"
 #include "util.hpp"
@@ -10,13 +10,13 @@
 static uint32_t ts_init = 0;
 static uint32_t ts_last = 0;
 struct {
-	float amplitude = 1;
+	uint8_t amplitude = 1;
 	uint32_t us_per_tick = 1;
 } config;
 struct {
 	uint8_t index;
+	uint8_t amplitude;
 	uint16_t frequency;
-	float amplitude;
 	bool active = false;
 } next;
 
@@ -25,7 +25,7 @@ constexpr uint64_t bm(int n) {
 }
 
 void scheduler::init() {
-	eeprom::jump(0);
+	data::jump(0);
 	tones::clear_all();
 	ts_init = micros();
 	running = true;
@@ -46,11 +46,11 @@ void scheduler::do_next() {
 
 	uint64_t v = 0;
 	uint8_t buff[8];
-	eeprom::read(buff, 1);
+	data::read(buff, 1);
 	
 	entry::Type type = buff[0] >> 5;
 	int entry_size = entry::get_size(type);
-	eeprom::read(buff + 1, entry_size - 1);
+	data::read(buff + 1, entry_size - 1);
 
 	for(int i = 0; i < entry_size; i++) {
 		v = (v << 8) | buff[i];
@@ -58,8 +58,8 @@ void scheduler::do_next() {
 
 	switch(type) {
 		case entry::Type::config: {
-			config.amplitude = *(float*)(buff + 4);
+			config.amplitude = v & bm(8);
-			v >>= 32;
+			v >>= 8;
 			config.us_per_tick = v & bm(29);
 			ts_init = micros();
 			break;
@@ -118,7 +118,7 @@ void scheduler::do_all() {
 }
 
 void scheduler::clear() {
-	eeprom::jump(0);
+	data::jump(0);
 	ts_last = 0;
 }
 

tone-generator.ino

@@ -6,6 +6,7 @@
 #include "util.hpp"
 #include "scheduler.hpp"
 #include "indicator.hpp"
+#include "data.hpp"
 
 static unsigned long int micros_at = 0;
 static bool led_state = true;
@@ -18,21 +19,27 @@ inline unsigned long micros_diff() {
 }
 
 void setup() {
+  Tone::init();
 	dac::init();
+  data::init();
   tones::init();
   scheduler::init();
   indicator::init();
 }
 
 void loop() {
-  if(scheduler::running && timing::at >= scheduler::timestamp) {
+  if(scheduler::running) {
+    if(timing::at >= scheduler::timestamp) {
       scheduler::do_all();
       indicator::update();
     }
+  } else {
+    data::check();
+  }
 
   timing::update();
   
-  float value = 0;
+  int32_t value = 0;
   uint32_t passed = timing::diff;
 
   for(int i = 0; i < tones::active; i++) {
@@ -41,6 +48,6 @@ void loop() {
     value += t.get();
   }
 
-  dac::set(value);
+  dac::set((value >> 8) + 127);
 }
 

tone.cpp

@@ -0,0 +1,10 @@
+
+#include <math.h>
+#include "tone.hpp"
+
+void Tone::init() {
+	for(unsigned i = 0; i < sizeof(sin_lookup); i++) {
+		sin_lookup[i] = round(sin((float)i / sizeof(sin_lookup) * M_PI * 2) * 127);
+	}
+}
+

tone.hpp

@@ -4,29 +4,14 @@
 #include <inttypes.h>
 #include <avr/pgmspace.h>
 
-inline const PROGMEM float SIN[] = {
-	0.000000, 0.024541, 0.049068, 0.073565, 0.098017, 0.122411, 0.146730, 0.170962, 0.195090, 0.219101, 0.242980, 0.266713, 0.290285, 0.313682, 0.336890, 0.359895,
-	0.382683, 0.405241, 0.427555, 0.449611, 0.471397, 0.492898, 0.514103, 0.534998, 0.555570, 0.575808, 0.595699, 0.615232, 0.634393, 0.653173, 0.671559, 0.689541,
-	0.707107, 0.724247, 0.740951, 0.757209, 0.773010, 0.788346, 0.803208, 0.817585, 0.831470, 0.844854, 0.857729, 0.870087, 0.881921, 0.893224, 0.903989, 0.914210,
-	0.923880, 0.932993, 0.941544, 0.949528, 0.956940, 0.963776, 0.970031, 0.975702, 0.980785, 0.985278, 0.989177, 0.992480, 0.995185, 0.997290, 0.998795, 0.999699,
-	1.000000, 0.999699, 0.998795, 0.997290, 0.995185, 0.992480, 0.989177, 0.985278, 0.980785, 0.975702, 0.970031, 0.963776, 0.956940, 0.949528, 0.941544, 0.932993,
-	0.923880, 0.914210, 0.903989, 0.893224, 0.881921, 0.870087, 0.857729, 0.844854, 0.831470, 0.817585, 0.803208, 0.788346, 0.773010, 0.757209, 0.740951, 0.724247,
-	0.707107, 0.689541, 0.671559, 0.653173, 0.634393, 0.615232, 0.595699, 0.575808, 0.555570, 0.534998, 0.514103, 0.492898, 0.471397, 0.449611, 0.427555, 0.405241,
-	0.382683, 0.359895, 0.336890, 0.313682, 0.290285, 0.266713, 0.242980, 0.219101, 0.195090, 0.170962, 0.146730, 0.122411, 0.098017, 0.073565, 0.049068, 0.024541,
-	0.000000, -0.024541, -0.049068, -0.073565, -0.098017, -0.122411, -0.146730, -0.170962, -0.195090, -0.219101, -0.242980, -0.266713, -0.290285, -0.313682, -0.336890, -0.359895,
-	-0.382683, -0.405241, -0.427555, -0.449611, -0.471397, -0.492898, -0.514103, -0.534998, -0.555570, -0.575808, -0.595699, -0.615232, -0.634393, -0.653173, -0.671559, -0.689541,
-	-0.707107, -0.724247, -0.740951, -0.757209, -0.773010, -0.788346, -0.803208, -0.817585, -0.831470, -0.844854, -0.857729, -0.870087, -0.881921, -0.893224, -0.903989, -0.914210,
-	-0.923880, -0.932993, -0.941544, -0.949528, -0.956940, -0.963776, -0.970031, -0.975702, -0.980785, -0.985278, -0.989177, -0.992480, -0.995185, -0.997290, -0.998795, -0.999699,
-	-1.000000, -0.999699, -0.998795, -0.997290, -0.995185, -0.992480, -0.989177, -0.985278, -0.980785, -0.975702, -0.970031, -0.963776, -0.956940, -0.949528, -0.941544, -0.932993,
-	-0.923880, -0.914210, -0.903989, -0.893224, -0.881921, -0.870087, -0.857729, -0.844854, -0.831470, -0.817585, -0.803208, -0.788346, -0.773010, -0.757209, -0.740951, -0.724247,
-	-0.707107, -0.689541, -0.671559, -0.653173, -0.634393, -0.615232, -0.595699, -0.575808, -0.555570, -0.534998, -0.514103, -0.492898, -0.471397, -0.449611, -0.427555, -0.405241,
-	-0.382683, -0.359895, -0.336890, -0.313682, -0.290285, -0.266713, -0.242980, -0.219101, -0.195090, -0.170962, -0.146730, -0.122411, -0.098017, -0.073565, -0.049068, -0.024541,
-};
-
 struct Tone {
 	uint32_t phase;
 	uint16_t frequency;
-	float amplitude;
+	uint8_t amplitude;
+
+	inline static int8_t sin_lookup[256];
+
+	static void init();
 
 	inline bool active() const {
 		return amplitude > 0;
@@ -36,9 +21,9 @@ struct Tone {
 		phase += t * frequency;
 	}
 
-	inline float get() const {
+	inline int get() const {
 		uint8_t id = phase >> 12;
-		return pgm_read_float(&SIN[id]) * amplitude;
+		return (int)sin_lookup[id] * amplitude;
 	}
 };