Introduction
• IoT Hub provides three options for device apps to expose functionality to a
back-end app:
• Direct methods for communications that require immediate confirmation of the result.
Direct methods are often used for interactive control of devices such as turning on a fan.
• Twin's desired properties for long-running commands intended to put the device into a
certain desired state. For example, set the telemetry send interval to 30 minutes.
• Cloud-to-device messages for one-way notifications to the device app.
• In this lab you will learn how to send cloud-to-device messages from your
IoT Hub to your device kit using the Azure Portal, and how to implement
custom functions activated by specific messages (for example, to turn on/off
an LED on the IoT Dk board)
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