In order to realize the acquisition and storage of underwater acoustic signals for aiming at the requirements of multi-channel, low power consumption and small volume for underwater receiver extension of sonar system, a multi-channel signal acquisition and storage system based on FPGA and STM32 with variable number of working channels and sampling frequency is designed, in which the system is consisted of 8 pieces, 8 channel and 24 bits high dynamic range Δ-Σ ADS1278 ADC chip to synchronous multi-channel analog signal acquisition. FPGA, as the acquisition sequence and logic control, reads and collates the ADC chip data and writes it into the internal high-capacity FIFO, and adds corresponding operations according to the characteristics of FIFO in an application. SMT32 single-chip microcomputer reads the FIFO data through the high-speed SPI interface with FPGA and writes the multi-channel data into the high-capacity SD card. The testing results have verified that the system has characteristics such as stable and reliable, easy configuration, low power consumption, can guarantee the multichannel data serial transmission, storage, accurate, up to 64 analog signals at the same time the real-time collection and storage, top 20 kHz sampling rate, the system total power of the system of about 3W, data rates up to 100 Mb/s, fully meet the needs of underwater sound acquisition system.
A 64-channel ultra-low power bioelectric signal acquisition system for brain-computer interface
