Abstract:

Remote experimentation has been an active research topic since the mid-90s, which has matured into one of the most interesting topics today. Remote labs are becoming important at a time when they have become a requirement to continue teaching during the Covid-19 pandemic.

The difference between a remote and a traditional hands-on experiment lies in the student's proximity. In the former, the student is physically in front of the experiment and is able to directly view and manipulate it. Meanwhile, in the latter, the student accesses, controls and views the process via the Internet.
The goal of this paper is to describe the development of WebLab-ARM, a new multi-instance remote laboratory for experimentation with embedded ARM microcontrollers. The laboratory has been developed by an association between WebLab-Deusto (a University of Deusto research group) and LabsLand (a spin-off of the research group).

WebLab-ARM is a remote laboratory that allows the end user to program, control, and debug a STM32 development board equipped with an ARM Cortex M0+ microcontroller. It offers a complete integrated online development environment that allows the student to perform experimentation in a similar manner as a hands-on lab. This family of microcontrollers are increasing in popularity, due to their massive use in current electronic products. This popularity in the market has conditioned its gradual incursion into the educational field, mainly in university studies.

Initially, from the code perspective, the student has an advanced code editor from which he/she can develop the code, compile it, and send it to the hardware platform.

Once the system is programmed, the environment loads the experimentation setup, providing a limited time to experiment with the system. The user can interact with the microcontroller through a series of virtualized input and output controls. The control system allows creating and capturing the necessary electrical signals, and transforming them into web requests that travel between the web interface and the microcontroller in real time.

Once the microcontroller behavior is tested, the experimentation session ends, and the user returns to the code perspective, allowing the system to be corrected or modified.

From an educational point of view, the laboratory has been designed according to a set of experiments that allow the student to assimilate programming skills for embedded systems. From basic practices on GPIO, timer management or analog signal analysis to communication buses or management of advanced power consumption modes, including advanced peripherals such as DMA.

A novel architecture developed in the research group has been used to turn this laboratory into a multi-instance laboratory. This makes it possible to support a greater number of concurrent users, and in the event of a failure in one of the available instances, it automatically redirects the users to the active instances, avoiding a total failure of the laboratory and giving the end user a feeling of robustness.

The preliminary results obtained during the development of the laboratory suggest that the laboratory has fulfilled the objectives set in its genesis, allowing four simultaneous users to access, program, control and debug a microcontroller of the ARM family. In the future, and thanks to the architecture that supports it, it is expected to increase the number of instances, in order to provide the laboratory with greater capacity and robustness.

Keywords:

Remote laboratory, remote labs, scalability, reliability, embedded systems, online experimentation, distance experimentation, distance learning, microcontroller.