![yellow led](https://i0.wp.com/www.exploringarduino.com/wp-content/uploads/2013/06/yellow-led.jpg?resize=350%2C214&ssl=1)
Image courtesy of SparkFun Electronics
An average 5mm Yellow LED has a 2V forward voltage drop, and a forward current of 20mA. Bright Yellow LEDs can have a forward voltage as high as 3.4V – check the datasheet. Don’t forget to use a current-limiting resistor when you connect an LED to your Arduino!