The complexity and scale of embedded software have increased. To improve the productivity, the mruby on TOPPERS embedded component system (TECS) framework, which employs a scripting language (i.e., lightweight Ruby) and supports component-based development, has been proposed. In the current mruby on TECS framework, mruby programs must be compiled and linked every time they are modified, because mruby bytecode are incorporated in the platform. Moreover, while the framework supports multiple virtual machines (VMs), developers must be familiar with the functions of real-time operating systems to effectively execute multiple mruby programs concurrently or in parallel. This paper proposed an extended mruby on TECS framework that improves development efficiency more than the current framework. We implemented a Bluetooth loader receives an mruby bytecode, and a RiteVM scheduler simplifies multitasking. Synchronization of initializing multiple tasks is also implemented using an Eventflag. Experimental results demonstrate the advantages of the proposed framework.
EV3RT is, to our knowledge, the first RTOS-based software platform for LEGO Mindstorms EV3 robotics kit. It is faster and more suitable for developing applications with real-time requirements than other existing software platforms. In practice, EV3RT has been selected as one of the officially supported platforms of ET Robocon, a popular robot competition in Japan, since 2015 and used by many participating teams to make their robots accomplish the assigned tasks more stably and precisely. In this paper, the usage and architecture of EV3RT are firstly introduced. We then explain TOPPERS/HRP2 kernel, the RTOS of EV3RT, and how to use its protection functionalities to build a reliable platform. A mechanism to support dynamic module loading in a static RTOS is proposed to implement the application loader for EV3RT. Implementation techniques like approach to reusing Linux device drivers are also described. Finally, the advantages of EV3RT are shown by evaluating and comparing its performance with other platforms.
Supporting deaf and hard-of-hearing (D/HH) people is a crucial social welfare measure. However, currently, communication support for D/HH people is insufficient for a conversation with multiple hearing people. In order to support D/HH people in these situations, this paper proposes a multi-modal speech visualization application, named Mieta, which provides various aspects of information about speech content. For the purpose of evaluating how actually useful the Mieta is, we conduct an evaluation experiment with actual nine D/HH students. As a result, Mieta contributes significantly to understanding, although it increases misunderstanding for D/HH people when there are voice recognition errors. Furthermore, subjects find that the Mieta's strength lies in its main characteristics, which includes multimodal speech visualization, whereas some find weakness in its voice recognition performance speed.