led-oled-thingy.ino

#include <SPI.h>
#include "SH1106_SPI.h"

//#define USE_FRAME_BUFFER

#ifdef USE_FRAME_BUFFER
SH1106_SPI_FB lcd;
#else
SH1106_SPI lcd;
#endif
//           R B G
byte led[] = {3,5,6};
bool ledStat = false;
byte ledColor[3] = {0,0,0};
unsigned long lastMillis[4];
unsigned short ledAnimTime = 1000;
unsigned long currentMillis;
float factor;

void runLED() {
  if(currentMillis - lastMillis[3] > 0) {
  if(currentMillis - lastMillis[0] <= ledAnimTime) {
    factor = (float)(currentMillis - lastMillis[0])/(float)ledAnimTime;
    analogWrite(led[0], (int)((float)ledColor[0] * factor));
    analogWrite(led[1], (int)((float)ledColor[1] * factor));
    analogWrite(led[2], (int)((float)ledColor[2] * factor));
  } else if(currentMillis - lastMillis[0] <= ledAnimTime*2) {
    factor = 1.0f - (float)(currentMillis - lastMillis[0])/(float)(ledAnimTime*2);
    analogWrite(led[0], (int)((float)ledColor[0] * factor));
    analogWrite(led[1], (int)((float)ledColor[1] * factor));
    analogWrite(led[2], (int)((float)ledColor[2] * factor));
  } else {
    lastMillis[0] = currentMillis;
  } 
  lastMillis[3] = currentMillis;
  }
}

void runDisplay() {
  if(currentMillis - lastMillis[1] >= 100) {
    lcd.clear();
    lcd.print(F("Hello world!"));
    lcd.gotoXY(0,1);
    lcd.print(millis());
    lcd.gotoXY(0,2);
    lcd.print(F("Factor "));
    lcd.print(factor);
    lastMillis[1] = currentMillis;
  }
}

void runCheck() {
  if(currentMillis - lastMillis[2] >= 8000) {
    ledColor[0] = random(0,256);
    ledColor[1] = random(0,256);
    ledColor[2] = random(0,256);
    lastMillis[2] = currentMillis;
  }
}

void setup(void)
{
	Serial.begin(9600);
  pinMode(led[0], OUTPUT);
  pinMode(led[1], OUTPUT);
  pinMode(led[2], OUTPUT);
	lcd.begin(false, true, 255, 3);
  lastMillis[0] = millis();
  lastMillis[1] = lastMillis[0];
  lastMillis[2] = lastMillis[0];
  lastMillis[3] = lastMillis[0];
  ledColor[0] = random(0,256);
  ledColor[1] = random(0,256);
  ledColor[2] = random(0,256);
}

void loop(void) 
{
	//check for time overflow
  if (millis() < lastMillis[0]) {
    //reset clocks
    lastMillis[0] = millis();
    lastMillis[1] = lastMillis[0];
    lastMillis[2] = lastMillis[0];
    lastMillis[3] = lastMillis[0];
  }
  currentMillis = millis();
  runCheck();
  runDisplay();
  runLED();
}

L20-L37 There is a very sudden drop in the brightness when fading out