与 IoT 相关的云端服务为数众多，例如：ThingSpeak、WoT．City、AWS、IBM Bluemix、MediaTek MCS、Google Firebase 等，并在透过这些云端服务可在对数据进行数据可视化、数据分析与其它的应用，而本文用Python将透过 Raspberry Pi 采集到的温湿度信息传送到 AWS IoT。
情境
材料与准备
1．准备 Raspberry Pi 3Model B 开发板
2．准备 Micro SD （已安装 Raspbian）
3．将 Micro SD 装入到 RaspberryPi 中
4．设定好网络
5．安装 GrovePi＋
6．安装 Grove – Temperatureand Humidity Sensor （D4）
7．安装 GROVE － LCD RGBBACKLIGHT （I2C－2）
8．安装 IDE （ Sublime Textor Visual Studio Code ）
Sensor， LCD， GrovePi＋ 与 RaspberryPi 连接如下图
AWS IoT 端
Step 1． 到 AWS 网站申请账号
Step 2． 登入 AWS 网站
Step 3． 点击 Services AWS IoT
Step 4． 点击 Create a resource
Step 5． 点击 Create a thing 输入 thing Name Create
Step 6． 点击刚建立的 thing
Step 7． 点击 Connect a device
Step 8． 点击 Node．js Generate certificate and policy
Step 9． 下载 private 与 public keys
Step 10． 点击 Confirm ＆connecting
Step 11． 点击 Return to ThingDetail
Raspberry Pi 端
Step 1． 透过 Python 读取温湿度信息并传送到AWS IoT
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＃ import Package
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import time
import datetime
import paho．mqtt．client as paho
import json
import ssl
import sys
sys．path．append（＇／home／pi／rpi／code／Package＇）
import grovepi
from grove＿rgb＿lcd import ＊
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＃ Set Pin No， AWS Config
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sensor ＝ 4
blue ＝ 0 ＃ The Blue colored sensor．
white ＝ 1 ＃ The White colored sensor．
connflag ＝ False
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＃ Set AWS Connection
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def on＿connect（client， userdata， flags，rc）：
global connflag
connflag ＝ True
print（＂Connection returned result： ＂ ＋ str（rc） ）
def on＿message（client， userdata， msg）：
print（msg．topic＋＂ ＂＋str（msg．payload））
mqttc ＝ paho．Client（）
mqttc．on＿connect ＝ on＿connect
mqttc．on＿message ＝ on＿message
awshost ＝ ＂a3iprlpgye4dmu．iot．us－west－2．amazonaws．com＂
awsport ＝ 8883
clientId ＝ ＂sensorData＂
thingName ＝ ＂sensorData＂
caPath ＝ ＂．／root－CA．crt＂
certPath ＝＂．／000cd28455－certificate．pem．crt＂
keyPath ＝ ＂．／000cd28455－private．pem．key＂
mqttc．tls＿set（caPath， certfile＝certPath， keyfile＝keyPath，cert＿reqs＝ssl．CERT＿REQUIRED， tls＿version＝ssl．PROTOCOL＿TLSv1＿2， ciphers＝None）
mqttc．connect（awshost， awsport， keepalive＝60）
mqttc．loop＿start（）
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＃ Publish AWS
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while True：
［temp，humidity］ ＝ grovepi．dht（sensor，blue）
print（＂temp ＝ ％．02f C humidity ＝％．02f％％＂％（temp， humidity））
t＝ time．time（）；
date ＝ datetime．datetime．fromtimestamp（t）．strftime（＇％Y％m％d％H％M％S＇）
if connflag ＝＝ True：
mqttc．publish（＂topic／sensorData＂，json．dumps（｛＂time＂： date， ＂temperature＂： temp，＂humidity＂： humidity｝）， qos＝1）
else：
print（＂waiting for connection．．．＂）
time．sleep（1）
Step 2． 将 Python Code 与 Keys 传送到 RaspberryPi
Step 3． 执行刚传到 Raspberry Pi 中的 Python 代码，python 檔名．py
Step 4． Console 执行画面
作者：Archer Huang
