Add: make digitalRead() for RGB_BUILTIN work (#9419)

* make digitalRead() for RGB_BUILTIN work

Standard Arduino-Way of blinking a LED can be the shortest with:

void loop() {
  static uint32_t ledticker = 0;
  if (millis() - ledticker > 1000) {
    ledticker = millis();
    digitalWrite(RGB_BUILTIN, !digitalRead(RGB_BUILTIN));
  }
}

Worked with the old LED_BUILTIN on Pin 2, now even works with Pin 48/neopixel.

* Add: make digitalRead() for RGB_BUILTIN work

Standard Arduino-Way of blinking a LED can be the shortest with:

void loop() {
  static uint32_t ledticker = 0;
  if (millis() - ledticker > 1000) {
    ledticker = millis();
    digitalWrite(RGB_BUILTIN, !digitalRead(RGB_BUILTIN));
  }
}

Worked with the old LED_BUILTIN on Pin 2, now even works with Pin 48/neopixel.

(Retry. Didn't sync my local sources. Sorry.)

Author: holgerlembke

Diff for: cores/esp32/esp32-hal-gpio.c

@@ -151,11 +151,16 @@ extern void ARDUINO_ISR_ATTR __pinMode(uint8_t pin, uint8_t mode)
     }
 }
 
+#ifdef RGB_BUILTIN
+uint8_t RGB_BUILTIN_storage = 0;
+#endif
+
 extern void ARDUINO_ISR_ATTR __digitalWrite(uint8_t pin, uint8_t val)
 {
     #ifdef RGB_BUILTIN
         if(pin == RGB_BUILTIN){
             //use RMT to set all channels on/off
+            RGB_BUILTIN_storage=val;
             const uint8_t comm_val = val != 0 ? RGB_BRIGHTNESS : 0;
             neopixelWrite(RGB_BUILTIN, comm_val, comm_val, comm_val);
             return;
@@ -170,6 +175,12 @@ extern void ARDUINO_ISR_ATTR __digitalWrite(uint8_t pin, uint8_t val)
 
 extern int ARDUINO_ISR_ATTR __digitalRead(uint8_t pin)
 {
+    #ifdef RGB_BUILTIN
+        if(pin == RGB_BUILTIN){
+            return RGB_BUILTIN_storage;
+        }
+    #endif
+
     if(perimanGetPinBus(pin, ESP32_BUS_TYPE_GPIO) != NULL){
         return gpio_get_level((gpio_num_t)pin);
     }