A Solution for EEG Acquisition Device Based on ESP32-S3 and LH7909

In recent years, the demand for portable devices for EEG signal acquisition has been increasing in various scenarios. These devices can be applied in clinical diagnostics or to monitor the health status of individuals in specific occupations. This paper presents the design of a portable EEG acquisition device that transmits its signals to a upper computer for waveform visualization, enabling diagnosis and research. The highlights of this work include, firstly, the use of the ESP32-S3 as the main control chip, which integrates a WiFi module. This eliminates the need for an external WiFi module, reducing the waste of IO resources. Secondly, we employed the LH7909 chip, which is produced by China's Legendsemi company, as a replacement for the Texas Instruments ADS1299. Without altering the original communication protocol or affecting existing functionality, we adapted the LH7909 to our EEG acquisition device and enhanced its performance, such as increasing the maximum sampling rate from 16000 sps to 32,000 sps and improving the common-mode rejection ratio. Experimental results demonstrate that our adaptations to the extended functions of the LH7909 successfully improved upon the original ADS1299 solution.