# 用Python點亮LED

## 一、歐姆定律與電阻分壓

學習電子學的歐姆電律與電阻分壓概念，有助於日後在面對輸出入腳位時，適當的進行電壓減壓或電壓分壓的動作，以免將實驗板的輸出入腳位燒毀

{% embed url="<https://youtu.be/ZsddxtpHd04>" %}

## 二、樹莓派GPIO與LED接線

介紹樹莓派的GPIO接腳基本概念，並且利用此概念，配合麵包板把電阻和紅色LED接線，接好後一切就緒，就可以開機進行程式撰寫！ 提醒一下：接線時，最好是在關機狀態，以免把樹莓派搞壞。

{% embed url="<https://youtu.be/SK6c16rVL6k>" %}

## 三、用Python點亮LED

Python語言易學易用，只要稍稍學習就可以開始運用它來開發程式，雖然是用「純英文來寫程式」，但稍微練習學幾個單字，就可以逐步上手。

{% embed url="<https://youtu.be/KNsqlqBrkuY>" %}

```python
import RPi.GPIO as gpio
import time

led = 17

gpio.setmode(gpio.BCM)
gpio.setup(led, gpio.OUT)

try:
    while True:
        gpio.output(led, gpio.HIGH)
        time.sleep(1)
        gpio.output(led, gpio.LOW)
        time.sleep(1)
except KeyboardInterrupt:
    pass

gpio.cleanup()
```

## 四、channel佔用警告修正及gpiozero模組初探

使用Rpi.GPIO，如果程式結束前沒有清除掉使用的channel，會出現警告訊息，雖然沒有問題，但最好還是利用try...except這種例外處理，接受鍵盤中斷訊息(Ctrl + C)，然後手動清除使用的資料。 除此之外，還有一個更方便好用的gpiozero模組，利用它僅使用一行指令就可以讓LED閃爍。

gpiozero官網：[https://gpiozero.readthedocs.io/en/st...](https://www.youtube.com/redirect?redir_token=oKdpEk5fdpQMGuJXmKgRCHM_1Rx8MTU1MjYzMTc2MUAxNTUyNTQ1MzYx\&q=https%3A%2F%2Fgpiozero.readthedocs.io%2Fen%2Fstable%2F\&event=video_description\&v=mUlVgjrG8gQ)

{% embed url="<https://youtu.be/mUlVgjrG8gQ>" %}


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