From 4c49c5b6a3c18db8d9062feb86286b3578a35bd0 Mon Sep 17 00:00:00 2001
From: Stephen Crane <jscrane@gmail.com>
Date: Thu, 6 Sep 2018 09:18:23 +0100
Subject: [PATCH] initial sound infrastructure
---
r65emu.h | 1 +
sound.cpp | 67 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
sound.h | 10 +++++++++
3 files changed, 78 insertions(+)
create mode 100644 sound.cpp
create mode 100644 sound.h
diff --git a/r65emu.h b/r65emu.h
index 7f53c3c..83c98a7 100644
--- a/r65emu.h
+++ b/r65emu.h
@@ -13,5 +13,6 @@
#include "timed.h"
#include "hardware.h"
#include "checkpoint.h"
+#include "sound.h"
#endif
diff --git a/sound.cpp b/sound.cpp
new file mode 100644
index 0000000..36c0a80
--- /dev/null
+++ b/sound.cpp
@@ -0,0 +1,67 @@
+#include <Arduino.h>
+#include <hardware.h>
+#include "timed.h"
+#include "sound.h"
+
+#if defined(DAC_SOUND) && defined(ESP_PLATFORM)
+#include <driver/dac.h>
+
+static portMUX_TYPE mux = portMUX_INITIALIZER_UNLOCKED;
+
+static dac_channel_t channel;
+
+static volatile const uint8_t *_bytes;
+static volatile unsigned _size, _off;
+static hw_timer_t *timer;
+
+void IRAM_ATTR timer_callback() {
+ portENTER_CRITICAL_ISR(&mux);
+
+ if (_off < _size)
+ dac_output_voltage(channel, _bytes[_off++]);
+ else {
+ _bytes = 0;
+ dac_output_disable(channel);
+ timerAlarmDisable(timer);
+ }
+
+ portEXIT_CRITICAL_ISR(&mux);
+}
+
+void Sound::begin(unsigned pin, unsigned freq) {
+ if (pin == 25)
+ channel = DAC_CHANNEL_1;
+ else if (pin == 26)
+ channel = DAC_CHANNEL_2;
+
+ timer = timerBegin(1, 80, true);
+ timerAttachInterrupt(timer, &timer_callback, true);
+ timerAlarmWrite(timer, 1000000 / freq, true);
+}
+
+const uint8_t *Sound::play(const uint8_t *bytes, unsigned size) {
+ portENTER_CRITICAL_ISR(&mux);
+
+ const uint8_t *play = (const uint8_t *)_bytes;
+ if (_off == _size) {
+ _bytes = bytes;
+ _size = size;
+ _off = 0;
+ dac_output_enable(channel);
+ timerAlarmEnable(timer);
+ play = bytes;
+ }
+
+ portEXIT_CRITICAL_ISR(&mux);
+ return play;
+}
+
+#else
+// does nothing by default
+void Sound::begin(unsigned channel, unsigned freq) {
+}
+
+const uint8_t *Sound::play(const uint8_t *bytes, unsigned size) {
+ return 0;
+}
+#endif
diff --git a/sound.h b/sound.h
new file mode 100644
index 0000000..a3a6ed5
--- /dev/null
+++ b/sound.h
@@ -0,0 +1,10 @@
+#ifndef __SOUND_H__
+#define __SOUND_H__
+
+class Sound {
+public:
+ void begin(unsigned pin, unsigned freq);
+ const uint8_t *play(const uint8_t *bytes, unsigned size);
+};
+
+#endif