Implemented tone and noTone

CMakeLists.txt

@@ -57,6 +57,7 @@ set(CORE_SRCS
   cores/esp32/stdlib_noniso.c
   cores/esp32/Stream.cpp
   cores/esp32/StreamString.cpp
+  cores/esp32/Tone.cpp
   cores/esp32/HWCDC.cpp
   cores/esp32/USB.cpp
   cores/esp32/USBCDC.cpp

cores/esp32/Arduino.h

@@ -195,6 +195,9 @@ extern "C" void configTime(long gmtOffset_sec, int daylightOffset_sec,
 extern "C" void configTzTime(const char* tz,
         const char* server1, const char* server2 = nullptr, const char* server3 = nullptr);
 
+void tone(uint8_t _pin, unsigned int frequency, unsigned long duration = 0, unsigned long duty = 50);
+void noTone(uint8_t _pin);
+
 // WMath prototypes
 long random(long);
 #endif /* __cplusplus */

cores/esp32/Tone.cpp

@@ -0,0 +1,49 @@
+#include <Arduino.h>
+#include "driver/ledc.h"
+
+#define BITS LEDC_TIMER_11_BIT // up to more than 25 kHz
+
+void noTone(uint8_t _pin){
+  ledc_stop(LEDC_LOW_SPEED_MODE, LEDC_CHANNEL_0, 0);
+}
+
+// duty in %
+void tone(uint8_t _pin, unsigned int frequency, unsigned long duration, unsigned long duty){
+  if(duty > 100){
+    log_e("Invalid duty parameter (%u) - must be between 0 and 100; Duty is in percents!", duty);
+    return;
+  }
+  ledc_timer_config_t ledc_timer = {
+    .speed_mode = LEDC_LOW_SPEED_MODE,    // timer mode
+    .duty_resolution = BITS,              // resolution of PWM duty
+    .timer_num = LEDC_TIMER_0,            // timer index
+    .freq_hz = frequency,                 // frequency of PWM signal
+    .clk_cfg = LEDC_AUTO_CLK              // Auto select the source clock
+  };
+  esp_err_t ret = ledc_timer_config(&ledc_timer);
+  if(ret){
+    log_e("Could not start tone; ledc_timer_config returned %d", ret);
+    return;
+  }
+
+  ledc_channel_config_t ledc_channel = {
+    .gpio_num   = _pin,                                /*!< the LEDC output gpio_num, if you want to use gpio16, gpio_num = 16 */
+    .speed_mode = LEDC_LOW_SPEED_MODE,                 /*!< LEDC speed speed_mode, high-speed mode or low-speed mode */
+    .channel    = LEDC_CHANNEL_0,                      /*!< LEDC channel (0 - 7) */
+    .intr_type  = LEDC_INTR_DISABLE,                   /*!< configure interrupt, Fade interrupt enable or Fade interrupt disable */
+    .timer_sel  = LEDC_TIMER_0,                        /*!< Select the timer source of channel (0 - 3) */
+    .duty       = duty * ((1<<BITS)/100),              /*!< LEDC channel duty, the range of duty setting is [0, (2**duty_resolution)] */
+    .hpoint     = 0,                                   /*!< LEDC channel hpoint value, the max value is 0xfffff */
+    .flags = {0}
+  };
+  ret = ledc_channel_config(&ledc_channel);
+  if(ret){
+    log_e("Could not start tone; ledc_channel_config returned %d", ret);
+    return;
+  }
+
+  if(duration){
+    vTaskDelay(pdMS_TO_TICKS(duration));
+    noTone(_pin);
+  }
+}