树莓派学习笔记（二）---准备篇

一、硬件准备

如果你跟我一样用的是树莓派，在开始学习前，请准备几个小东西，便于学习，或提高效率。

以下整理出来的东西在淘宝上都有很多卖家。亦有整合包买。

1、GPIO扩展版

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2、GPIO排线

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3、各种各样的杜邦线

• 公对公
  • 
• 母对母
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• 母对公
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4、发光二极管和电阻

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• 分别买发光二极管和电阻，也可以买途中这种直接串联的

5、37种传感器

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• 记得在淘宝店下载驱动和传感器说明哦。

二、软件准备

# 先更新软件包
sudo apt-get update & upgrade
# 安装WiringPi
sudo apt-get install wiringpi
# WiringPi安装完成后，可以使用下面的命令测试是否安装成功
sudo gpio -v
# 执行后如下
╭─ ~                                        peigen@peigen 22:50:22 ─╮
╰─❯ sudo gpio -v                                                   ─╯
gpio version: 2.61
Copyright (c) 2012-2018 Gordon Henderson
This is free software with ABSOLUTELY NO WARRANTY.
For details type: gpio -warranty

Raspberry Pi Details:
  Type: Pi 4B, Revision: 05, Memory: 8192MB, Maker: Sony 
  * Device tree is enabled.
  *--> Raspberry Pi 4 Model B Rev 1.5
  * This Raspberry Pi supports user-level GPIO access.

# 执行gpio readall 可以查看当前gpio口状态
╭─ ~                                        peigen@peigen 22:51:22 ─╮
╰─❯ gpio readall                                                   ─╯
+-----+-----+---------+------+---+---Pi 4B--+---+------+---------+-----+-----+
 | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |
 +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
 |     |     |    3.3v |      |   |  1 || 2  |   |      | 5v      |     |     |
 |   2 |   8 |   SDA.1 |   IN | 1 |  3 || 4  |   |      | 5v      |     |     |
 |   3 |   9 |   SCL.1 |   IN | 1 |  5 || 6  |   |      | 0v      |     |     |
 |   4 |   7 | GPIO. 7 |   IN | 1 |  7 || 8  | 1 | IN   | TxD     | 15  | 14  |
 |     |     |      0v |      |   |  9 || 10 | 1 | IN   | RxD     | 16  | 15  |
 |  17 |   0 | GPIO. 0 |   IN | 0 | 11 || 12 | 0 | IN   | GPIO. 1 | 1   | 18  |
 |  27 |   2 | GPIO. 2 |   IN | 0 | 13 || 14 |   |      | 0v      |     |     |
 |  22 |   3 | GPIO. 3 |   IN | 0 | 15 || 16 | 0 | IN   | GPIO. 4 | 4   | 23  |
 |     |     |    3.3v |      |   | 17 || 18 | 0 | OUT  | GPIO. 5 | 5   | 24  |
 |  10 |  12 |    MOSI |   IN | 0 | 19 || 20 |   |      | 0v      |     |     |
 |   9 |  13 |    MISO |   IN | 0 | 21 || 22 | 0 | OUT  | GPIO. 6 | 6   | 25  |
 |  11 |  14 |    SCLK |   IN | 0 | 23 || 24 | 1 | IN   | CE0     | 10  | 8   |
 |     |     |      0v |      |   | 25 || 26 | 1 | IN   | CE1     | 11  | 7   |
 |   0 |  30 |   SDA.0 |   IN | 1 | 27 || 28 | 1 | IN   | SCL.0   | 31  | 1   |
 |   5 |  21 | GPIO.21 |   IN | 1 | 29 || 30 |   |      | 0v      |     |     |
 |   6 |  22 | GPIO.22 |   IN | 1 | 31 || 32 | 0 | IN   | GPIO.26 | 26  | 12  |
 |  13 |  23 | GPIO.23 |   IN | 0 | 33 || 34 |   |      | 0v      |     |     |
 |  19 |  24 | GPIO.24 |   IN | 0 | 35 || 36 | 0 | IN   | GPIO.27 | 27  | 16  |
 |  26 |  25 | GPIO.25 |   IN | 0 | 37 || 38 | 0 | IN   | GPIO.28 | 28  | 20  |
 |     |     |      0v |      |   | 39 || 40 | 0 | IN   | GPIO.29 | 29  | 21  |
 +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
 | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |
 +-----+-----+---------+------+---+---Pi 4B--+---+------+---------+-----+-----+

树莓派的物理引脚、BCM引脚和WiringPi引脚是三种不同的定义，下面这张图看起来更清晰美观一些：

当然，这里先不用死记硬背，以后有太多的机会翻出来复习，慢慢都会记得的。

重点记得图中的3.3 Volts、5 Volts和GND的位置。3.3V、5V对应正极，GND对应负极。

另外，我本身的技术栈是Java，理所应当在树莓派上也玩玩Java。