# IoT Helper: A Lightweight and Extensible Framework for Fast-Prototyping IoT Architectures
### Contributions  
We present an easy-to-go framework called IoT \(\mathsf{Helper}\) that allows for quick prototyping in terms of IoT/IIoT-enabled applications. The main contributions made by IoT \(\mathsf{Helper}\) are the following:  
* We introduce a new framework for monitoring and controlling embedded devices. The framework is based on a generic architecture that can be used with many classes of sensors and actuators. Thus, the framework can be effectively used to facilitate the development of intelligent applications in domotics and industry.
* The system requires minimum configuration and virtually no application logic in order to remotely access the data and control devices. As a consequence, application developers can focus on the development of higher-level applications that use data collected by IoT \(\mathsf{Helper}\) in order to gain insights.
* IoT \(\mathsf{Helper}\) is cloud-enabled by default. It is based on a publish-and-subscribe protocol for decoupling the production of data from its consumption and may leverage public-cloud platforms in order to scale to very large volumes of data. At the same time, coherently with its agile inspiration, the framework also allows for on-premise deployments that can be preferred in some scenarios due to data protection and privacy concerns.
* Declarative configuration and architectural flexibility are achieved by means of an abstract representation of the components of the frameworks, i.e., the embedded hardware, sensors, actuators, message endpoints and message formats. This conceptualization, described in more detail in the following sections, is a crucial component of our implementation.
* Finally, IoT \(\mathsf{Helper}\) is based on inexpensive, open-source components from the Arduino [5] platform. This significantly lowers costs and adoption times and concretely fosters a more agile approach to IoT and IIoT. In this paper, we discuss how the choices made in designing the framework help users to quickly prototype working solutions and to test them. Then, after initial tests are completed, a final development phase of the missing app components can be started. During this phase, Arduino also allows for industrializing the production of embedded devices for the production phase, thus, further lowering costs.
* In the paper we present two concrete application scenarios: The first one is a typical domotics application for controlling the fan of a fireplace extractor chimney. The second one is a complex industrial application with respect to monitoring welding pliers of a robot arm. In addition to these, we report comprehensive experimental results to study the scalability of our framework. In fact, one of the main questions we intend to investigate in this paper is what level of scalability can be achieved with a lean generic framework based on inexpensive components such as ours. We consider the answer to this question an important contribution of the paper because it proves that IIoT-enabling technologies can now be considered as a commodity; therefore, users may be more ambitious in experimenting with their usage.