From 0ad9cb174127df4348781bc4343e525a0195cdb0 Mon Sep 17 00:00:00 2001
From: Stephen Crane <jscrane@gmail.com>
Date: Thu, 27 Jul 2023 10:32:20 +0100
Subject: [PATCH] just use tone()/noTone() to support PWM sound now (#17)

---
 hw/esp32/dac.h    |  1 -
 hw/esp8266/pwm.h  |  1 -
 hw/lilygo-vga32.h |  6 +---
 sound_pwm.cpp     | 74 +++--------------------------------------------
 sound_pwm.h       |  3 +-
 5 files changed, 6 insertions(+), 79 deletions(-)

diff --git a/hw/esp32/dac.h b/hw/esp32/dac.h
index a7c3c8d..a980e52 100644
--- a/hw/esp32/dac.h
+++ b/hw/esp32/dac.h
@@ -1,4 +1,3 @@
 // sound: dac and pwm
 #define DAC_SOUND	25
 #define PWM_SOUND	25
-#define PWM_DUTY	20	// 20/1024 -> volume
diff --git a/hw/esp8266/pwm.h b/hw/esp8266/pwm.h
index 8e4413c..c29a942 100644
--- a/hw/esp8266/pwm.h
+++ b/hw/esp8266/pwm.h
@@ -1,4 +1,3 @@
 // sound
 #define PWM_SOUND	D2
-#define PWM_DUTY	20	// 20/1024 -> volume
 #define PWM_TOP		1024
diff --git a/hw/lilygo-vga32.h b/hw/lilygo-vga32.h
index 44a9668..0c510d4 100644
--- a/hw/lilygo-vga32.h
+++ b/hw/lilygo-vga32.h
@@ -10,11 +10,7 @@
 
 // sound: dac and pwm
 #define DAC_SOUND	25
-
-// PWM doesn't work
-// "assert failed: ledc_clk_cfg_to_global_clk ledc.c:443 (false)"
-//#define PWM_SOUND	25
-//#define PWM_DUTY	20	// 20/1024 -> volume
+#define PWM_SOUND	25
 
 // "tape" storage...
 #undef USE_SD
diff --git a/sound_pwm.cpp b/sound_pwm.cpp
index f4d4972..de4c2f5 100644
--- a/sound_pwm.cpp
+++ b/sound_pwm.cpp
@@ -1,82 +1,16 @@
 #include <Arduino.h>
 #include "sound_pwm.h"
-#include "hardware.h"
 
-#if defined(PWM_SOUND) && defined(ESP32)
-#include <driver/ledc.h>
-
-#define CHANNEL		LEDC_CHANNEL_0
-#define TIMER		LEDC_TIMER_0
-#define SPEED_MODE	LEDC_HIGH_SPEED_MODE
-
-void PWM::begin(unsigned gpio) {
-	ledc_timer_config_t timer_conf;
-  	timer_conf.duty_resolution = LEDC_TIMER_10_BIT;
-  	timer_conf.freq_hz = 440;
-  	timer_conf.speed_mode = SPEED_MODE;
-  	timer_conf.timer_num = TIMER;
-  	ESP_ERROR_CHECK(::ledc_timer_config(&timer_conf));
-
-  	ledc_channel_config_t ledc_conf;
-  	ledc_conf.channel = CHANNEL;
-  	ledc_conf.duty = 0;
-  	ledc_conf.gpio_num = gpio;
-  	ledc_conf.intr_type = LEDC_INTR_DISABLE;
-  	ledc_conf.speed_mode = SPEED_MODE;
-  	ledc_conf.timer_sel = TIMER;
-  	ESP_ERROR_CHECK(::ledc_channel_config(&ledc_conf));
-}
-
-void PWM::set_duty(unsigned duty) {
-	ESP_ERROR_CHECK(::ledc_set_duty(SPEED_MODE, CHANNEL, duty));
-	ESP_ERROR_CHECK(::ledc_update_duty(SPEED_MODE, CHANNEL));
-}
-
-void PWM::stop() {
-	set_duty(0);
-}
-
-void PWM::set_freq(unsigned freq) {
-      ESP_ERROR_CHECK(::ledc_set_freq(SPEED_MODE, TIMER, freq));
-}
-
-#elif defined(PWM_SOUND) && defined(ESP8266)
-#include <core_esp8266_waveform.h>
-
-static unsigned gpio, duty;
-const unsigned period = 1024;
+static unsigned gpio;
 
 void PWM::begin(unsigned gpio) {
 	::gpio = gpio;
-	pinMode(gpio, OUTPUT);
-}
-
-void PWM::set_duty(unsigned duty) {
-	::duty = duty;
 }
 
 void PWM::stop() {
-	stopWaveform(gpio);
+	noTone(gpio);
 }
 
-void PWM::set_freq(unsigned freq) {
-	uint32_t t = 1000000 / freq;
-	uint32_t h = duty * t / period;
-	startWaveform(gpio, h, t-h, 0);
+void PWM::start(unsigned freq) {
+	tone(gpio, freq);
 }
-
-#else
-#pragma message "No PWM"
-
-void PWM::begin(unsigned gpio) {
-}
-
-void PWM::set_duty(unsigned duty) {
-}
-
-void PWM::stop() {
-}
-
-void PWM::set_freq(unsigned freq) {
-}
-#endif
diff --git a/sound_pwm.h b/sound_pwm.h
index e4d87e4..89e5609 100644
--- a/sound_pwm.h
+++ b/sound_pwm.h
@@ -4,9 +4,8 @@
 class PWM {
 public:
 	void begin(unsigned gpio);
-	void set_duty(unsigned duty);
 	void stop();
-	void set_freq(unsigned freq);
+	void start(unsigned freq);
 };
 
 #endif