## 4 Results and Discussion
### Limitations & Future Work  
While developing the RSC prototype, we encountered several limitations that influenced the final prototype and identified areas for future exploration and refinement. These limitations encompassed various domains, including technical constraints, software challenges, and the absence of extensive user evaluations. Regardless, each limitation reveals a unique set of difficulties and learning opportunities. The prototype's electronic system faces several power-supply challenges. Notably, the absence of an integrated battery restricts the device's portability to areas with power outlets. We initially estimated the peak power draw of all devices could exceed 15W. During development, we included a USB connector to attach a second power supply in case this became a recurring issue. We do not recommend using two separate power supplies due to the risk of ground loops, voltage-level variances and uneven load distribution. An alternative solution for this scenario is to use a higher-rated power supply. Relying on a custom expansion board means users aiming to build their own RSC must understand the electronics and how to use specialised tools, complicating basic setup and maintenance. Additionally, the wiring in the prototype's internals is highly disorganised (see ElectroCircuits [36]), causing excessive crosstalk and interference. Meanwhile, the end-of-life status of the Voice Bonnet v2 without OEM (Original Equipment Manufacturer) support limits future scalability and hinders maintenance options. Finally, the servos we used produce power-line noise when active due to insufficient power-line filtering, impacting overall system reliability. Mechanically, the servos emit loud noises due to insufficient sound-dampening measures. We could mitigate this issue by switching to higher-quality servos or alternate motor types, like small brushless direct-current gimbal motors. At the same time, the single degree of freedom of both flippers limits the prototype's expressive motion gestures. Adding encoder-based odometry and perhaps a more sophisticated shoulder joint with more degrees of freedom could substantially enrich the prototype's functionality and expressiveness. Finally, we observed durability concerns with regard to the LCD panel and the lid-panel locking mechanism, which typically lasts \(\sim\)100 cycles in regular use. These issues indicate a need for design improvements to enhance longevity and the user experience. One of the significant technical constraints involved optimising the accuracy and reliability of the open-source speech-to-text and text-to-speech systems, particularly concerning handling diverse accents and dialects and ensuring their integration with the RSC. Despite leveraging the pyttsx3 library to enhance voice communication, the generated voice maintained a robotic timbre and presented comprehensibility challenges, indicating a need for further work to provide a more natural and engaging text-to-speech solution to enhance social interaction (Req 1). Google's archiving of AIY projects and the associated GitHub repositories in February 2023 made finding support and documentation more difficult, slowing overall progress. Integrating OpenAI's NLP API created an additional issue by introducing latency due to the offloading of computation to online services, impacting real-time interactions. For instance, users wait approximately 6 s when starting a conversation and an additional 3 s before receiving a reply to a question. The effect of this delay on overall immersion when studying with the RSC needs to be investigated. At the same time, development should focus on optimising the software and hardware integration to reduce latency and improve the system's overall responsiveness. During the prototyping phase in spring 2023, we utilised OpenAI's GPT-3 (text_davinci003) API, which was considered state-of-the-art at the time but which was deprecated in January 2024.