You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
65 lines
1.9 KiB
65 lines
1.9 KiB
/* fade w/o pwm
|
|
|
|
Fades an LED that is not connected to a PWM pin
|
|
This was modified from the Blink without Delay code
|
|
|
|
https://create.arduino.cc/projecthub/hs_education_georgia/fade-led-without-using-pwm-08a82f
|
|
|
|
The circuit:
|
|
* LED attached from pin 13 to ground.
|
|
* Note: on most Arduinos, there is already an LED on the board
|
|
that's attached to pin 13, so no hardware is needed for this example.
|
|
|
|
*/
|
|
|
|
// constants won't change. Used here to set pin numbers:
|
|
const int ledPin = 14; // the number of the LED pin
|
|
|
|
// Variables will change:
|
|
int ledState = LOW; // ledState used to set the LED
|
|
long previousMicros = 0; // will store the last time the blink cycle occured
|
|
|
|
// the follow variables is a long because the time, measured in microseconds,
|
|
// will quickly become a bigger number than can be stored in an int.
|
|
long intervalLength = 500; // interval at which to blink (microseconds)
|
|
long onInterval = 20; // on or HIGH interval length
|
|
long currentInterval; // length of the current interval
|
|
int fadeLength = 200;
|
|
int fadeCount = 0;
|
|
int intervalDirection = 1;
|
|
|
|
void setup() {
|
|
// set the digital pin as output:
|
|
pinMode(ledPin, OUTPUT);
|
|
}
|
|
|
|
void loop()
|
|
{
|
|
|
|
unsigned long currentMicros = micros();
|
|
|
|
currentInterval = currentMicros - previousMicros;
|
|
|
|
if (currentInterval <= onInterval) {
|
|
ledState = HIGH;
|
|
}
|
|
else {
|
|
ledState = LOW;
|
|
}
|
|
|
|
if(currentInterval > intervalLength) {
|
|
// save the last time you blinked the LED
|
|
previousMicros = currentMicros;
|
|
fadeCount++;
|
|
if (fadeCount > fadeLength) {
|
|
fadeCount = 0;
|
|
onInterval += (intervalDirection * 20);
|
|
if (onInterval <= 20 || onInterval >= intervalLength) {
|
|
intervalDirection *= -1; // change the direction of the fade ( positive - brighter / negative - dimmer)
|
|
}
|
|
}
|
|
}
|
|
|
|
// set the LED with the ledState of the variable:
|
|
digitalWrite(ledPin, ledState);
|
|
}
|