Prompt: Create a fading LED attached to a microcontroller. Your LED should be interruptible by either a pushbutton, analog input, or serial input.
link to the original code by Tom Igoe: xSquared Fade Curve
Modified code:
//xSquareFade code original by Tom Igoe 2019
//modified January 2020 by Nok
//set up pot for potentiometer and v for mapped value of potentiometer
int pot;
int v;
int currentLevel = 1;
int change = 1;
byte levelTable[256]; // pre-calculated PWM levels
void setup() {
// put your setup code here, to run once:
// pre-calculated the PWM levels from the formula:
fillLevelTable();
}
void loop() {
// put your main code here, to run repeatedly:
//assign pot to pin A0 and map pot to v
pot = analogRead(A0);
v = map(pot, 0, 1023, 1, 10);
// decrease or increase by 1 point each time
// if at the bottom or top, change the direction:
if (currentLevel <= 0 || currentLevel >= 255) {
change = -change;
}
currentLevel += change;
//PWM output the result:
analogWrite(5, levelTable[currentLevel]*v);
delay(10);
Serial.println(levelTable[currentLevel]);
}
void fillLevelTable() {
//set the range of values:
float maxValue = 255;
//iterate over the array and calculate the right value for it:
for (int l = 0; l <= maxValue; l++) {
//square the current value:
float lightLevel = pow(l,2);
//map the result back to a 0-255 range:
lightLevel = map(lightLevel, 0, 65535, 0, 255);
levelTable[l] = lightLevel;
}
}