zephyrCommon: Add tone and noTone

cores/arduino/zephyrCommon.cpp

@@ -210,6 +210,51 @@ PinStatus digitalRead(pin_size_t pinNumber) {
   return (gpio_pin_get_dt(&arduino_pins[pinNumber]) == 1) ? HIGH : LOW;
 }
 
+struct k_timer arduino_pin_timers[ARRAY_SIZE(arduino_pins)];
+struct k_timer arduino_pin_timers_timeout[ARRAY_SIZE(arduino_pins)];
+
+void tone_expiry_cb(struct k_timer *timer) {
+  const struct gpio_dt_spec *spec = (gpio_dt_spec*)k_timer_user_data_get(timer);
+  gpio_pin_toggle_dt(spec);
+}
+
+void tone_timeout_cb(struct k_timer *timer) {
+  pin_size_t pinNumber = (pin_size_t)(uintptr_t)k_timer_user_data_get(timer);
+  noTone(pinNumber);
+}
+
+void tone(pin_size_t pinNumber, unsigned int frequency, unsigned long duration) {
+  struct k_timer *timer = &arduino_pin_timers[pinNumber];
+  const struct gpio_dt_spec *spec = &arduino_pins[pinNumber];
+  k_timeout_t timeout;
+
+  pinMode(pinNumber, OUTPUT);
+
+  if (frequency == 0) {
+    gpio_pin_set_dt(spec, 0);
+    return;
+  }
+
+  timeout = K_NSEC(NSEC_PER_SEC / (2 * frequency));
+
+  k_timer_init(timer, tone_expiry_cb, NULL);
+  k_timer_user_data_set(timer, (void*)spec);
+  gpio_pin_set_dt(spec, 1);
+  k_timer_start(timer, timeout, timeout);
+
+  if(duration > 0) {
+    timer = &arduino_pin_timers_timeout[pinNumber];
+    k_timer_init(timer, tone_timeout_cb, NULL);
+    k_timer_user_data_set(timer, (void*)(uintptr_t)pinNumber);
+    k_timer_start(timer, K_MSEC(duration), K_NO_WAIT);
+  }
+}
+
+void noTone(pin_size_t pinNumber) {
+  k_timer_stop(&arduino_pin_timers[pinNumber]);
+  gpio_pin_set_dt(&arduino_pins[pinNumber], 0);
+}
+
 void delay(unsigned long ms) { k_sleep(K_MSEC(ms)); }
 
 void delayMicroseconds(unsigned int us) { k_sleep(K_USEC(us)); }