Arduino UNO 硬體直接控制LED燈亮度 ( Control a LED Lightness without Any Code )

本文要用硬體直接控制 LED 燈的亮度，順便了解一些Arduino板子上的腳位。注意：當可變電阻的電阻值太小時，LED有可能會燒掉。
This tutorial will teach how to use UNO to control a LED lightness without coding. Note: the LED might be broken when the resistor value is to too small. 所用到的材料有(Materials)：

1. Arduino UNO 主板 x 1

2. LED燈 x 1 (顏色不拘 the color you like)

3. B10K 可變電阻 10k Potentiometer x 1

4. 杜邦線公對公 male to male wire x 2

5. 麵包板 breadboard x 1

6. 9V電池與9V電池扣或 USB Cable，供電用 9v battery and 9v clip, or USB cable for UNO
根據下面的電路圖將電路接好(The circuit)

注意LED燈的短腳要接在GND。The short leg(cathode) is connected to the GND.

完成圖如下(The completed circuit)：

思考如何接線才能控制多顆LED燈的亮度。
Exercise: how do we control multiple LEDs?

Originally published at yunlinsong.blogspot.com on November 20, 2018.