Set RGB LED digitally for boot logo & flashlight

Instead of PWM, basic digital output is used to control the RGB LED in the
bootLogo() and flashlight() functions. This reduces code size for sketches
which don't use the setRGBled() function. In bootLogo(), instead of dimming
the red LED, the red then green then blue LEDs are lit in sequence at full
brightness.

digitalWriteRGB() was added as a public function and is also used for the
changes above.

src/Arduboy2.cpp

@@ -49,32 +49,32 @@ void Arduboy2Base::begin()
 void Arduboy2Base::flashlight()
 {
   // sendLCDCommand(OLED_ALL_PIXELS_ON); // smaller than allPixelsOn()
-  setRGBled(255,255,255);
+  digitalWriteRGB(RGB_ON, RGB_ON, RGB_ON);
   while(!pressed(DOWN_BUTTON)) {
     idle();
   }
-  setRGBled(0,0,0);
+  digitalWriteRGB(RGB_OFF, RGB_OFF, RGB_OFF);
 }
 
 void Arduboy2Base::systemButtons() {
   while (pressed(B_BUTTON)) {
-    digitalWrite(BLUE_LED, LOW); // turn on blue LED
+    digitalWrite(BLUE_LED, RGB_ON); // turn on blue LED
     sysCtrlSound(UP_BUTTON + B_BUTTON, GREEN_LED, 0xff);
     sysCtrlSound(DOWN_BUTTON + B_BUTTON, RED_LED, 0);
     delay(200);
   }
 
-  digitalWrite(BLUE_LED, HIGH); // turn off blue LED
+  digitalWrite(BLUE_LED, RGB_OFF); // turn off blue LED
 }
 
 void Arduboy2Base::sysCtrlSound(uint8_t buttons, uint8_t led, uint8_t eeVal) {
   if (pressed(buttons)) {
-    digitalWrite(BLUE_LED, HIGH); // turn off blue LED
+    digitalWrite(BLUE_LED, RGB_OFF); // turn off blue LED
     delay(200);
-    digitalWrite(led, LOW); // turn on "acknowledge" LED
+    digitalWrite(led, RGB_ON); // turn on "acknowledge" LED
     EEPROM.update(EEPROM_AUDIO_ON_OFF, eeVal);
     delay(500);
-    digitalWrite(led, HIGH); // turn off "acknowledge" LED
+    digitalWrite(led, RGB_OFF); // turn off "acknowledge" LED
 
     while (pressed(buttons)) {} // Wait for button release
   }
@@ -82,12 +82,18 @@ void Arduboy2Base::sysCtrlSound(uint8_t buttons, uint8_t led, uint8_t eeVal) {
 
 void Arduboy2Base::bootLogo()
 {
-  // setRGBled(10,0,0);
-  for(int8_t y = -18; y<=24; y++) {
-    setRGBled(24-y, 0, 0);
+  digitalWrite(RED_LED, RGB_ON);
+
+  for(int8_t y = -18; y <= 24; y++) {
+    if (y == -4) {
+      digitalWriteRGB(RGB_OFF, RGB_ON, RGB_OFF); // green LED on
+    }
+    else if (y == 24) {
+      digitalWriteRGB(RGB_OFF, RGB_OFF, RGB_ON); // blue LED on
+    }
 
     clear();
-    drawBitmap(20,y, arduboy_logo, 88, 16, WHITE);
+    drawBitmap(20, y, arduboy_logo, 88, 16, WHITE);
     display();
     delay(27);
     // longer delay post boot, we put it inside the loop to
@@ -98,7 +104,7 @@ void Arduboy2Base::bootLogo()
   }
 
   delay(750);
-  setRGBled(0,0,0);
+  digitalWrite(BLUE_LED, RGB_OFF);
 }
 
 /* Frame management */

src/core/core.cpp

@@ -312,6 +312,17 @@ void ArduboyCore::setRGBled(uint8_t red, uint8_t green, uint8_t blue)
   // only blue on devkit
   digitalWrite(BLUE_LED, ~blue);
 #endif
+}
+
+  void ArduboyCore::digitalWriteRGB(uint8_t red, uint8_t green, uint8_t blue)
+{
+#ifdef ARDUBOY_10
+  digitalWrite(RED_LED, red);
+  digitalWrite(GREEN_LED, green);
+  digitalWrite(BLUE_LED, blue);
+#elif defined(AB_DEVKIT)
+  digitalWrite(BLUE_LED, blue);
+#endif
 }
 
 /* Buttons */

src/core/core.h

@@ -32,6 +32,8 @@
 #define SAFE_MODE    //< include safe mode (44 bytes)
 #endif
 
+#define RGB_ON LOW   // for digitially setting an RGB LED on
+#define RGB_OFF HIGH // for digitially setting an RGB LED off
 
 #ifdef ARDUBOY_10
 
@@ -254,9 +256,19 @@ public:
     /// send a single byte command to the OLED
     void static sendLCDCommand(uint8_t command);
 
-    /// set the light output of the RGB LEB
+    /// set the light output of the RGB LED
+    /**
+     * The brightness of each LED can be set to a value from
+     * 0 (fully off) to 255 (fully on).
+     */
     void static setRGBled(uint8_t red, uint8_t green, uint8_t blue);
 
+    /// set the RGB LEDs digitally, to either fully on or fully off
+    /**
+     * Use value RGB_ON or RGB_OFF for each color of LED.
+     */
+    void static digitalWriteRGB(uint8_t red, uint8_t green, uint8_t blue);
+
     /// boots the hardware
     /**
      * - sets input/output/pullup mode for pins