Design of a low-cost voice-controlled smart home hub with IoT connectivity

This paper presents the design of a low-cost smart home hub based on the STM32F103C8T6 microcontroller. The system integrates local voice control using an offline ASR module, environmental sensing with a DHT11 sensor, and cloud communication via an ESP8266 Wi-Fi module using the MQTT protocol. Time synchronization is achieved through NTP, maintaining a 2.5 ms accuracy. Performance evaluations demonstrate that the device provides reliable ambient data and stable voice interaction without internet dependency. The results confirm the systems feasibility as a compact, cost-effective solution for smart home applications.