now with sawtooth, square, and triangle waves :D

README.md

@@ -20,12 +20,12 @@ This uses an AVR microcontroller (ATMega328P-PU).
 
 # Instruction Set
 
-| ID | Name     | Size | Layout |
+| ID | Name       | Size | Layout |
 |-|-|-|-|
-| 0  | stop     | 1    | id (3), empty (5) |
+| 0  | stop       | 1    | id (3), empty (5) |
-| 1  | setup    | 8    | id (3), us_per_tick (29), amplitude (8), size (24) |
+| 1  | setup      | 8    | id (3), us_per_tick (29), amplitude (8), size (24) |
-| 2  | set      | 3    | id (3), index (5), frequency (12), empty (4) |
+| 2  | set        | 3    | id (3), index (5), frequency (12), mode (2), empty (2) |
-| 3  | set-ts   | 5    | id (3), index (5), ticks (20), frequency (12) |
+| 3  | set-ts     | 5    | id (3), index (5), ticks (18), frequency (12), mode (2) |
-| 4  | clear    | 1    | id (3), index (5) |
+| 4  | clear      | 1    | id (3), index (5) |
-| 5  | clear-ts | 4    | id (3), index (5), ticks (20), empty (4) |
+| 5  | clear-ts   | 4    | id (3), index (5), ticks (18), empty (6) |
 

entry.hpp

@@ -9,13 +9,14 @@ struct Checker {
 namespace entry {
 
 	enum Type : uint8_t {
-		stop     = 0,
+		stop       = 0,
-		config   = 1,
+		config     = 1,
-		set      = 2,
+		set        = 2,
-		set_ts   = 3,
+		set_ts     = 3,
-		clear    = 4,
+		clear      = 4,
-		clear_ts = 5,
+		clear_ts   = 5,
-		tempo    = 6,
+		set_saw    = 6,
+		set_saw_ts = 7,
 	};
 
 	enum NextType {
@@ -28,6 +29,7 @@ namespace entry {
 		uint8_t index;
 		uint8_t amplitude;
 		uint16_t frequency;
+		uint8_t mode;
 	};
 
 	struct Tempo {
@@ -47,8 +49,6 @@ namespace entry {
 			return 4;
 		case Type::config:
 			return 8;
-		case Type::tempo:
-			return 7;
 		case Type::stop:
 		default:
 			return 1;

scheduler.cpp

@@ -20,10 +20,7 @@ struct {
 } config;
 struct {
 	entry::NextType type = entry::nt_none;
-	union {
+	entry::Tone tone;
-		entry::Tone tone;
-		entry::Tempo tempo;
-	};
 } next;
 
 void scheduler::reset() {
@@ -36,19 +33,12 @@ static void do_next() {
 	
 	int i = 1;
 
-	if(state == State::play) {
+	if(next.type == entry::nt_tone) {
-		switch(next.type) {
+		if(state == State::play) {
-		case entry::nt_tone:
+			tones::set(next.tone.index, next.tone.frequency, next.tone.amplitude, next.tone.mode);
-			tones::set(next.tone.index, next.tone.frequency, next.tone.amplitude);
-			break;
-		case entry::nt_tempo:
-			ts_init += next.tempo.ticks * config.us_per_tick;
-			tick_offset = next.tempo.ticks;
-			config.us_per_tick = next.tempo.us_per_tick;
-			break;
 		}
+		next.type = entry::nt_none;
 	}
-	next.type = entry::nt_none;
 
 	uint64_t v = 0;
 	uint8_t buff[8];
@@ -80,7 +70,9 @@ static void do_next() {
 			break;
 		}
 		case entry::Type::set: {
-			v >>= 4;
+			v >>= 2;
+			next.tone.mode = v & bm(2);
+			v >>= 2;
 			next.type = entry::nt_tone;
 			next.tone.frequency = v & bm(12);
 			v >>= 12;
@@ -90,10 +82,12 @@ static void do_next() {
 		}
 		case entry::Type::set_ts: {
 			next.type = entry::nt_tone;
+			next.tone.mode = v & bm(2);
+			v >>= 2;
 			next.tone.frequency = v & bm(12);
 			v >>= 12;
-			uint32_t ticks = (v & bm(20)) - tick_offset;
+			uint32_t ticks = (v & bm(18)) - tick_offset;
-			v >>= 20;
+			v >>= 18;
 			next.tone.index = v & bm(5);
 			next.tone.amplitude = config.amplitude;
 			timestamp = ticks * config.us_per_tick + ts_init;
@@ -107,9 +101,9 @@ static void do_next() {
 			break;
 		}
 		case entry::Type::clear_ts: {
-			v >>= 4;
+			v >>= 6;
-			uint32_t ticks = (v & bm(20)) - tick_offset;
+			uint32_t ticks = (v & bm(18)) - tick_offset;
-			v >>= 20;
+			v >>= 18;
 			next.type = entry::nt_tone;
 			next.tone.index = v & bm(5);
 			next.tone.frequency = 0;

tone.cpp

@@ -2,6 +2,10 @@
 #include <math.h>
 #include "tone.hpp"
 
+static int8_t abs(int8_t v) {
+	return v >= 0 ? v : -v;
+}
+
 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

@@ -5,9 +5,18 @@
 #include "util.hpp"
 
 struct Tone {
+
+	enum Type {
+		tt_sine     = 0,
+		tt_saw      = 1,
+		tt_square   = 2,
+		tt_triangle = 3,
+	};
+
 	uint32_t phase;
 	uint16_t frequency;
 	uint8_t amplitude;
+	Type mode;
 
 	inline static int8_t sin_lookup[256];
 
@@ -22,8 +31,23 @@ struct Tone {
 	}
 
 	inline int get() const AW_IN {
-		uint8_t id = phase >> 12;
+		int v;
-		return (int)sin_lookup[id] * amplitude;
+		switch(mode) {
+		case tt_sine:
+			v = sin_lookup[(phase >> 12) & 255];
+			break;
+		case tt_saw:
+			v = (int8_t)((phase >> 12) & 255);
+			break;
+		case tt_square:
+			v = phase & 0x80000 ? -127 : 127;
+			break;
+		case tt_triangle:
+			v = (phase >> 11) & 0x1ff;
+			v = (v > 0xff ? 1 : -1) * (int8_t)phase;
+			break;
+		}
+		return v * amplitude;
 	}
 };
 

tones.cpp

@@ -40,16 +40,17 @@ void tones::clear_all() {
 	active = 0;
 }
 
-void tones::set(uint8_t index, uint16_t frequency, float amplitude) {
+void tones::set(uint8_t index, uint16_t frequency, float amplitude, Tone::Type mode) {
 	if(index >= size(all)) {
 		return;
 	}
 	Tone& t = all[lookup[index]];
 	if(amplitude == 0) {
-		t = {0, 0, 0};
+		t = {0, 0, 0, Tone::tt_sine};
 	} else {
 		t.frequency = frequency;
 		t.amplitude = amplitude;
+		t.mode = mode;
 	}
 }
 

tones.hpp

@@ -9,11 +9,10 @@ namespace tones {
 	inline Tone all[32];
 	inline uint8_t lookup[size(all)];
 	inline uint8_t rlookup[size(all)];
-
 	inline int active;
 
 	void init();
-	void set(uint8_t index, uint16_t frequency, float amplitude);
+	void set(uint8_t index, uint16_t frequency, float amplitude, Tone::Type mode);
 	void clear_all();
 	void recalc();
 }