int redPin=3;
int testPin=2;
int dt=500;
int inc=1;
int dec=1;
int brightness=0;
void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(redPin, OUTPUT);
  pinMode(testPin, OUTPUT);

}
void loop() {
analogWrite(redPin,brightness);
brightness++;
delay(500);
}