Lumii
A talking plush toy for children: electronics, firmware, voice AI and parent app
Client
Toys with soul s.r.o.
Country
Czech Republic
Industry
Consumer electronics / Toys
Deployment
Private Cloud
Ollsoft is the technical partner of Toys with soul s.r.o., the Prague company developing Lumii, a plush toy that talks with children. We designed the electronics around an ESP32-S3 with two microphones, an amplifier and battery charging, and wrote the firmware in C++ on ESP-IDF: Bluetooth setup, real-time voice over WebRTC and over-the-air updates that fall back to the previous version if a new one fails. The backend (FastAPI, PostgreSQL) manages child profiles, parental controls and subscriptions, and parents set up the toy in a Flutter app. Speech runs through Azure OpenAI; a safety prompt keeps conversations age-appropriate and sends the child to a parent on sensitive topics. Lumii is a prototype before market launch, with a waitlist at lumiitoy.com. Ollsoft's founder is one of the company's co-founders.
Key outcomes
- Custom electronics: ESP32-S3, two microphones, amplifier, USB-C charging
- Real-time voice conversation over WebRTC
- Over-the-air firmware updates that fall back to the last working version
- Encrypted connections and short-lived tokens for each voice session
- Parent app with child profiles and parental controls
- Safety prompt: age-appropriate topics, sensitive questions go to a parent
- Prepared for the Cyber Resilience Act: a talking connected toy is an important product, class I (Annex III)
- Prototype before market launch