Azure provides SDK for the device side as well as the PaaS services which are a part of its IoT stack. Microsoft Azure IoT SDK are open source are easily available to download from GitHub. It supports various language like C#, Node.JS, C, Java. you can use any machine which is capable of development with these technologies.

Azure IoT device SDK, which runs on the IoT device side enables the device for communicating with the IoT Hub. It uses the protocols available. The application deployed on the device then sends the telemetry data to cloud. For this purpose, the device needs to be registered with the IoT Hub as well. These SDKs also help run the bidirectional commands which make it easy to control and manage the device.

Currently these IoT device SDKs support different programming languages, such as ANSI C using .NET C#, and for Java, Node.js and Python as well.

Likewise, these SDKs also support various OS and platforms on which we can develop the applications. Microsoft has made these SDKs portable on any platform and OS. By making these SDKs open source, they are readily available for download on GitHub to make any customization as per your needs.

Azure IoT service SDK provides the code that is used in building an IoT application that directly works with the IoT Hub. It will enable you to manage devices, read messages sent by devices, or even send commands to devices to control actions at the device end.

The GitHub URL to download these open source SDK's are:

• Azure IoT service SDK for .NET
• Azure IoT service SDK for Node.js
• Azure IoT service SDK for Java
• Azure IoT service SDK for Python

Azure IoT gateway SDKs are used to simplify the connectivity to IoT Hub when we have scenarios which vary drastically between industries, and even between customers within the same industry. The Azure IoT gateway SDK can be used to implement custom-made IoT solutions for your scenario. The device SDKs can be used to implement an IoT client that facilitates connectivity to the cloud. It simply uses the supported communication protocol, it will extract and process the data using the protocol supported before sending it to the cloud.

Download the source code for IoT gateway SDK from GitHub: https://github.com/Azure/azure-iot-gateway-sdk.