feat(ledc): max resolution review

cores/esp32/esp32-hal-ledc.c

@@ -330,13 +330,13 @@ bool ledcWrite(uint8_t pin, uint32_t duty) {
   ledc_channel_handle_t *bus = (ledc_channel_handle_t *)perimanGetPinBus(pin, ESP32_BUS_TYPE_LEDC);
   if (bus != NULL) {
 
-    uint8_t group = (bus->channel / SOC_LEDC_CHANNEL_NUM), channel = (bus->channel % SOC_LEDC_CHANNEL_NUM);
 
-    //Fixing if all bits in resolution is set = LEDC FULL ON
-    uint32_t max_duty = (1 << bus->channel_resolution) - 1;
+    uint8_t group = (bus->channel / SOC_LEDC_CHANNEL_NUM), channel = (bus->channel % SOC_LEDC_CHANNEL_NUM);
+    uint32_t max_duty = (1 << bus->channel_resolution); // Max LEDC duty
 
-    if ((duty == max_duty) && (max_duty != 1)) {
-      duty = max_duty + 1;
+    if (duty > max_duty) {
+      log_w("Target duty %d was adjusted to the maximum duty %d", duty, max_duty);
+      duty = max_duty;
     }
 
     if (ledc_set_duty(group, channel, duty) != ESP_OK) {
@@ -368,11 +368,11 @@ bool ledcWriteChannel(uint8_t channel, uint32_t duty) {
   //Fixing if all bits in resolution is set = LEDC FULL ON
   uint32_t resolution = 0;
   ledc_ll_get_duty_resolution(LEDC_LL_GET_HW(), group, timer, &resolution);
+  uint32_t max_duty = (1 << resolution); // Max LEDC duty
 
-  uint32_t max_duty = (1 << resolution) - 1;
-
-  if ((duty == max_duty) && (max_duty != 1)) {
-    duty = max_duty + 1;
+  if (duty > max_duty) {
+    log_w("Target duty %d was adjusted to the maximum duty %d", duty, max_duty);
+    duty = max_duty;
   }
 
   if (ledc_set_duty(group, channel, duty) != ESP_OK) {
@@ -435,15 +435,16 @@ uint32_t ledcWriteTone(uint8_t pin, uint32_t freq) {
     bus->channel_resolution = 10;
 
     uint32_t res_freq = ledc_get_freq(group, bus->timer_num);
-    ledcWrite(pin, 0x1FF);
+    ledcWrite(pin, 0x200); // LEDC 50% duty is 2^10 / 2 = 0x200
     return res_freq;
   }
   return 0;
 }
 
 uint32_t ledcWriteNote(uint8_t pin, note_t note, uint8_t octave) {
-  const uint16_t noteFrequencyBase[12] = {//   C        C#       D        Eb       E        F       F#        G       G#        A       Bb        B
-                                          4186, 4435, 4699, 4978, 5274, 5588, 5920, 6272, 6645, 7040, 7459, 7902
+  const uint16_t noteFrequencyBase[12] = {
+    // C   C#     D    Eb    E     F     F#    G     G#    A     Bb     B
+    4186, 4435, 4699, 4978, 5274, 5588, 5920, 6272, 6645, 7040, 7459, 7902
   };
 
   if (octave > 8 || note >= NOTE_MAX) {
@@ -557,6 +558,21 @@ static bool ledcFadeConfig(uint8_t pin, uint32_t start_duty, uint32_t target_dut
 #endif
     uint8_t group = (bus->channel / SOC_LEDC_CHANNEL_NUM), channel = (bus->channel % SOC_LEDC_CHANNEL_NUM);
 
+    uint32_t max_duty = (1 << bus->channel_resolution); // Max LEDC duty
+
+    if (target_duty > max_duty) {
+      log_w("Final duty %d was adjusted to the maximum duty %d", target_duty, max_duty);
+      target_duty = max_duty;
+    }
+    if (start_duty > max_duty) {
+      log_w("Starting duty %d was adjusted to the maximum duty %d", start_duty, max_duty);
+      start_duty = max_duty;
+    }
+    if (start_duty >= target_duty) {
+      log_e("Starting duty must be lower than the final duty");
+      return false;
+    }
+
     // Initialize fade service.
     if (!fade_initialized) {
       ledc_fade_func_install(0);
@@ -569,15 +585,6 @@ static bool ledcFadeConfig(uint8_t pin, uint32_t start_duty, uint32_t target_dut
     ledc_cbs_t callbacks = {.fade_cb = ledcFnWrapper};
     ledc_cb_register(group, channel, &callbacks, (void *)bus);
 
-    //Fixing if all bits in resolution is set = LEDC FULL ON
-    uint32_t max_duty = (1 << bus->channel_resolution) - 1;
-
-    if ((target_duty == max_duty) && (max_duty != 1)) {
-      target_duty = max_duty + 1;
-    } else if ((start_duty == max_duty) && (max_duty != 1)) {
-      start_duty = max_duty + 1;
-    }
-
 #if SOC_LEDC_SUPPORT_FADE_STOP
     ledc_fade_stop(group, channel);
 #endif
@@ -779,6 +786,17 @@ void analogWrite(uint8_t pin, int value) {
         return;
       }
     }
+    // Arduino API says that duty goes from 0 to (2^resolution) - 1
+    // But LEDC works with duty from 0 to (2^resolution)
+    // Therefore, it will adjust Arduino MAX Duty to be the LEDC MAx Duty
+    uint32_t max_duty = (1 << bus->channel_resolution) - 1;
+    if (value < 0 || value > max_duty) {
+      log_e("Duty is out of range. Valid duty range for pin %d is 0 to %d", pin, max_duty);
+      return;
+    }
+    if (value == max_duty) {
+      value = max_duty + 1;
+    }    
     ledcWrite(pin, value);
   }
 }

libraries/ESP32/examples/AnalogOut/LEDCFade/LEDCFade.ino

@@ -17,7 +17,7 @@
 
 // define starting duty, target duty and maximum fade time
 #define LEDC_START_DUTY  (0)
-#define LEDC_TARGET_DUTY (4095)
+#define LEDC_TARGET_DUTY (4096)
 #define LEDC_FADE_TIME   (3000)
 
 bool fade_ended = false;  // status of LED fade

libraries/ESP32/examples/AnalogOut/LEDCGammaFade/LEDCGammaFade.ino

@@ -21,7 +21,7 @@
 
 // define starting duty, target duty and maximum fade time
 #define LEDC_START_DUTY  (0)
-#define LEDC_TARGET_DUTY (4095)
+#define LEDC_TARGET_DUTY (4096)
 #define LEDC_FADE_TIME   (2000)
 
 // gamma factor for mathematical calculation

libraries/ESP32/examples/AnalogOut/LEDCSingleChannel/LEDCSingleChannel.ino

@@ -26,7 +26,7 @@
 #define LEDC_CHANNEL 0
 
 int brightness = 0;  // how bright the LED is
-int fadeAmount = 5;  // how many points to fade the LED by
+int fadeAmount = 4;  // how many points to fade the LED by
 
 void setup() {
   // Use single LEDC channel 0 for both pins
@@ -42,7 +42,7 @@ void loop() {
   brightness = brightness + fadeAmount;
 
   // reverse the direction of the fading at the ends of the fade:
-  if (brightness <= 0 || brightness >= 255) {
+  if (brightness <= 0 || brightness >= 256) {
     fadeAmount = -fadeAmount;
   }
   // wait for 30 milliseconds to see the dimming effect

libraries/ESP32/examples/AnalogOut/LEDCSoftwareFade/LEDCSoftwareFade.ino

@@ -20,13 +20,13 @@
 #define LED_PIN 5
 
 int brightness = 0;  // how bright the LED is
-int fadeAmount = 5;  // how many points to fade the LED by
+int fadeAmount = 4;  // how many points to fade the LED by
 
 // Arduino like analogWrite
 // value has to be between 0 and valueMax
-void ledcAnalogWrite(uint8_t pin, uint32_t value, uint32_t valueMax = 255) {
+void ledcAnalogWrite(uint8_t pin, uint32_t value, uint32_t valueMax = 256) {
   // calculate duty, 4095 from 2 ^ 12 - 1
-  uint32_t duty = (4095 / valueMax) * min(value, valueMax);
+  uint32_t duty = (4096 / valueMax) * min(value, valueMax);
 
   // write duty to LEDC
   ledcWrite(pin, duty);
@@ -45,7 +45,7 @@ void loop() {
   brightness = brightness + fadeAmount;
 
   // reverse the direction of the fading at the ends of the fade:
-  if (brightness <= 0 || brightness >= 255) {
+  if (brightness <= 0 || brightness >= 256) {
     fadeAmount = -fadeAmount;
   }
   // wait for 30 milliseconds to see the dimming effect

libraries/ESP32/examples/AnalogOut/ledcWrite_RGB/ledcWrite_RGB.ino

@@ -17,7 +17,7 @@ const boolean invert = true;  // set true if common anode, false if common catho
 
 uint8_t color = 0;         // a value from 0 to 255 representing the hue
 uint32_t R, G, B;          // the Red Green and Blue color components
-uint8_t brightness = 255;  // 255 is maximum brightness, but can be changed.  Might need 256 for common anode to fully turn off.
+uint16_t brightness = 255; // 255 is maximum brightness, but can be changed.
 
 // the setup routine runs once when you press reset:
 void setup() {
@@ -33,12 +33,12 @@ void setup() {
 
 // void loop runs over and over again
 void loop() {
-  Serial.println("Send all LEDs a 255 and wait 2 seconds.");
+  Serial.println("Send all LEDs a 256 and wait 2 seconds.");
   // If your RGB LED turns off instead of on here you should check if the LED is common anode or cathode.
   // If it doesn't fully turn off and is common anode try using 256.
-  ledcWrite(ledR, 255);
-  ledcWrite(ledG, 255);
-  ledcWrite(ledB, 255);
+  ledcWrite(ledR, 256);
+  ledcWrite(ledG, 256);
+  ledcWrite(ledB, 256);
   delay(2000);
   Serial.println("Send all LEDs a 0 and wait 2 seconds.");
   ledcWrite(ledR, 0);