How To Make an IoT Service

To build an IoT Service from scratch, it is recommended to follow the steps below. IoT Services come in many forms, and exact steps will depend on the detailed requirements of the IoT Service.

  1. Find API and SDK bindings for target service. An IoT service connects the Unify Framework with an external service. Service should be interpreted in the broadest sense; it can be a cloud service, or it can be a UI operated by end users. Or something in between. The first step in writing an IoT Service is determining which APIs and SDKs to use for the target service. If the IoT Service connects to a cloud service, then the cloud service SDK is a good place to start. Alternatively, choosing a framework with good bindings to the cloud service. If the IoT Service is a UI, then a UI framework should be chosen based on the product requirements.

  2. Choose an MQTT client. Now choose an MQTT client based on the programming language and frameworks selected in the previous step. Most MQTT clients should be compatible with the Unify Framework. If encryption is desired, make sure to choose a client that supports certificate-based TLS.

  3. Discover nodes using MQTT topics. Discovering nodes and resources that can be displayed or manipulated is fundamental to any IoT Service. This is achieved by subscribing to particular MQTT topics. See the Service Discovery chapter of the Unify Specification.

  4. Implement Network Management. If the IoT Service needs to do network management, consider which operations are needed and implement them as described in the Network Management chapter of the Unify Specification.

  5. Interact with nodes using MQTT topics. Interacting with the nodes by either reading out status or controlling their state is fundamental to most IoT services. Subscribe and publish to the relevant MQTT topics as described in the Application Level Control chapter of the Unify Specification.

  6. Consider re-using appropriate shared components from the Unify Framework codebase. A valuable feature of Unify is the common components shared by many modules of the SDK. Code reuse saves both development time and offers IoT Service users a uniform experience operating and configuring different IoT services.

The Unify Framework provides a number of components that are candidates for re-use in IoT Services. They are listed below.

  1. Unify MQTT Client. The MQTT client is built on top of Eclipse Mosquitto MQTT and handles MQTT connection, subscribing and publishing. It implements re-connections and caching of published messages, which have been published while the client has been disconnected from the broker. See the section Unify Library Framework/MQTT Client in Unify Documentation for details.

  2. Logging System. The logging system features logging with severity level tagging and log filtering. See the section Unify Library Framework/Logging System in the Unify Documentation for details.

  3. Config System. The config system implements parsing of config files and command line arguments. See the Unify Library Framework/Config System in Unify Documentation for details.

The UPVL and GMS applications use the shared components and are good examples to peruse. They can be found in the Unify source code in the applications/gms/ and applications/upvl/ directories.