一、基础硬件介绍

最权威最详细信息科参见官网：
树莓派官网
树莓派提供了一组对外的 IO 接口，称为 GPIO（通用 IO 接口，General-purpose input/output）。
在这里插入图片描述
它的 40 个脚的定义如下图：

通过 GPIO ，树莓派可以与其他电子元件连接。

二、LED 控制脚本

下面，我们使用 Node 脚本控制 LED。
上图中第11针（GPIO17）这个针脚的电流是脚本可以控制的。接下来我们将在树莓派上新建一个实验目录，并安装控制 GPIO 的 Node 模块rpio。

1.安装Node模块

npm是什么？简单说npm就是“把各种代码模块集中管理的工具”，要什么代码就不要四处搜罗了，直接在这里就可以找到了。

安装npm

sudo apt-get install npm

结果发现报错，说有依赖项冲突什么的。找到解决方法：
inux的版本依赖问题很令人纠结，不过我们可以通过使用aptitude软件包管理器来解决这个依赖问题，aptitude是可以选择合适的版本与匹配软件安装。

安装aptitude工具

sudo apt-get install aptitude

再利用aptitude来安装npm

sudo aptitude install npm

上述命令执行后：

会弹出是否接受：第一次要选择N 不知道这是个啥情况，然后第二次选择Y，然后以后好像就正常了，选择Y接受建议就行了。好了现在npm可以使用了，可以接着在树莓派上安装node了

sudo apt install nodejs

查看版本

node -v

在这里插入图片描述
版本号是12.22.5

新建一个实验目录，运行：

 
mkdir led-demo && cd led-demo
npm init -y
npm install -S rpio

发现执行“npm install -S rpio”的时候出错。
在这里插入图片描述
换了几种安装方式还是错的：
sudo npm cache clean -f
sudo npm install npm -g
也是错误，报错信息：
request to https://registry.npmjs.org/npm failed, reason: connect EHOSTUNREACH 104.16.16.35:443
使用“sudo npm install rpio”一样的结果
报错信息：

pi@raspberrypi:~ $ sudo npm install rpio
npm ERR! code EHOSTUNREACH
npm ERR! syscall connect
npm ERR! errno EHOSTUNREACH
npm ERR! request to https://registry.npmjs.org/rpio failed, reason: connect EHOSTUNREACH 104.16.17.35:443

npm ERR! A complete log of this run can be found in:
npm ERR!     /root/.npm/_logs/2022-03-11T09_51_24_796Z-debug.log

使用“npm config list -l”查看信息：

pi@raspberrypi:~ $ npm config list -l
; "default" config from default values

_auth = (protected) 
access = null 
all = false 
allow-same-version = false 
also = null 
always-auth = false 
audit = true 
audit-level = null 
auth-type = "legacy" 
before = null 
bin-links = true 
browser = null 
ca = null 
cache = "/home/pi/.npm" 
cache-lock-retries = 10 
cache-lock-stale = 60000 
cache-lock-wait = 10000 
cache-max = null 
cache-min = 10 
cafile = null 
call = "" 
cert = null 
ci-name = null 
cidr = null 
color = true 
commit-hooks = true 
depth = null 
description = true 
dev = false 
diff = [] 
diff-dst-prefix = "" 
diff-ignore-all-space = false 
diff-name-only = false 
diff-no-prefix = false 
diff-src-prefix = "" 
diff-text = false 
diff-unified = null 
dry-run = false 
editor = "vi" 
engine-strict = false 
fetch-retries = 2 
fetch-retry-factor = 10 
fetch-retry-maxtimeout = 60000 
fetch-retry-mintimeout = 10000 
fetch-timeout = 300000 
force = false 
foreground-script = false 
format-package-lock = true 
fund = true 
git = "git" 
git-tag-version = true 
global = false 
global-style = false 
globalconfig = "/etc/npmrc" 
heading = "npm" 
https-proxy = null 
if-present = false 
ignore-prepublish = false 
ignore-scripts = false 
include = [] 
include-staged = false 
init-author-email = "" 
init-author-name = "" 
init-author-url = "" 
init-license = "ISC" 
init-module = "/home/pi/.npm-init.js" 
init-version = "1.0.0" 
init.author.email = "" 
init.author.name = "" 
init.author.url = "" 
init.license = "ISC" 
init.module = "/home/pi/.npm-init.js" 
init.version = "1.0.0" 
json = false 
key = null 
legacy-bundling = false 
legacy-peer-deps = false 
link = false 
local-address = undefined 
loglevel = "notice" 
logs-max = 10 
; long = false ; overridden by cli
maxsockets = 50 
message = "%s" 
metrics-registry = "https://registry.npmjs.org/" 
node-options = null 
node-version = "v12.22.5" 
noproxy = null 
npm-version = "7.5.2" 
offline = false 
; omit = [] ; overridden by cli
only = null 
optional = true 
otp = null 
package = [] 
package-lock = true 
package-lock-only = false 
parseable = false 
prefer-offline = false 
prefer-online = false 
; prefix = "/usr" ; overridden by builtin
preid = "" 
production = false 
progress = true 
proxy = null 
read-only = false 
rebuild-bundle = true 
registry = "https://registry.npmjs.org/" 
rollback = true 
save = true 
save-bundle = false 
save-dev = false 
save-exact = false 
save-optional = false 
save-prefix = "^" 
save-prod = false 
scope = "" 
script-shell = null 
scripts-prepend-node-path = "warn-only" 
searchexclude = null 
searchlimit = 20 
searchopts = "" 
searchstaleness = 900 
shell = "/bin/bash" 
shrinkwrap = true 
sign-git-commit = false 
sign-git-tag = false 
sso-poll-frequency = 500 
sso-type = "oauth" 
strict-peer-deps = false 
; strict-ssl = true ; overridden by user
tag = "latest" 
tag-version-prefix = "v" 
timing = false 
tmp = "/tmp" 
umask = 0 
unicode = true 
update-notifier = true 
usage = false 
; user-agent = "npm/{npm-version} node/{node-version} {platform} {arch} {ci}" ; overridden by cli
userconfig = "/home/pi/.npmrc" 
version = false 
versions = false 
viewer = "man" 

; "builtin" config from /usr/share/nodejs/npm/npmrc

globalignorefile = "/etc/npmignore" 
prefix = "/usr/local" 

; "user" config from /home/pi/.npmrc

strict-ssl = false 

; "cli" config from command line options

long = true 
omit = [] 
user-agent = "npm/7.5.2 node/v12.22.5 linux arm"