30分钟连接树莓派到微软云 Azure IoT Hub，并将数据进行可视化

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树莓派是很多动手达人必备的小玩具，本节内容，让我们拿出树莓派，在30分钟内，将树莓派连接到微软云Azure的IoT Hub，然后将温湿度曲线可视化。
（本节内容完整视频在文章末尾。）

本节内容中，树莓派发送的数据是模拟出来的，并没有真实的连接到传感器，您可以选购不同的传感器来采集真实的环境信息。

Azure IoT Hub 为我们提供了设备与云双向通讯的能力，通过多种语言的SDK，我们能轻松快速的将树莓派接入到云。本案例使用微软官方代码，示例代码一共约70行，非常简单。

关于IoT Hub的更多内容，请参考：

https://mp.weixin.qq.com/s?__biz=Mzg2OTEyNzMzOQ==&mid=2247483659&idx=1&sn=68cdff986d7dcc9b6233e48ba820300c&chksm=cea084cff9d70dd9898cbec3b2fe3e06175f7288acd244af9cc6f1b5fe0e5aa0fc946da585ad&scene=21#wechat_redirect

时序见解（Azure Time Series Insights）用来存储时间序列的值，同时提供UI，将数据可视化。

时序见解和IoT Hub可以无缝连接，无需写代码即可将上传到IoT Hub的数据进行可视化。

树莓派上传数据的代码：

import random
import time

# Using the Python Device SDK for IoT Hub:
#   https://github.com/Azure/azure-iot-sdk-python
# The sample connects to a device-specific MQTT endpoint on your IoT Hub.
from azure.iot.device import IoTHubDeviceClient, Message

# The device connection string to authenticate the device with your IoT hub.
# Using the Azure CLI:
# az iot hub device-identity show-connection-string --hub-name {YourIoTHubName} --device-id MyNodeDevice --output table
CONNECTION_STRING = "{your string}"

# Define the JSON message to send to IoT Hub.
TEMPERATURE = 20.0
HUMIDITY = 60
MSG_TXT = '{{"temperature": {temperature},"humidity": {humidity}}}'

def iothub_client_init():
    # Create an IoT Hub client
    client = IoTHubDeviceClient.create_from_connection_string(CONNECTION_STRING)
    return client

def iothub_client_telemetry_sample_run():

    try:
        client = iothub_client_init()
        print ( "IoT Hub device sending periodic messages, press Ctrl-C to exit" )

        while True:
            # Build the message with simulated telemetry values.
            temperature = TEMPERATURE + (random.random() * 15)
            humidity = HUMIDITY + (random.random() * 20)
            msg_txt_formatted = MSG_TXT.format(temperature=temperature, humidity=humidity)
            message = Message(msg_txt_formatted)

            # Add a custom application property to the message.
            # An IoT hub can filter on these properties without access to the message body.
            if temperature > 30:
              message.custom_properties["temperatureAlert"] = "true"
            else:
              message.custom_properties["temperatureAlert"] = "false"

            # Send the message.
            print( "Sending message: {}".format(message) )
            client.send_message(message)
            print ( "Message successfully sent" )
            time.sleep(1)

    except KeyboardInterrupt:
        print ( "IoTHubClient sample stopped" )

if __name__ == '__main__':
    print ( "IoT Hub Quickstart #1 - Simulated device" )
    print ( "Press Ctrl-C to exit" )
    iothub_client_telemetry_sample_run()

IoT Hub 接入文档，请参考：

https://docs.azure.cn/zh-cn/iot-hub/quickstart-send-telemetry-python

树莓派系统下载：

https://www.raspberrypi.org/downloads/

Micro SD卡格式化工具：

https://www.sdcard.org/downloads/index.html

树莓派系统写入Micro SD卡工具：

https://sourceforge.net/projects/win32diskimager/

完整实战视频如下：

https://v.qq.com/x/page/f3025q4e75x.html