Features: This edition is suitable for ADAU1401/1701/1702 learning and product use. The ADAU1401 is more stable than the ADAU1701 in the harsh working environment of -40-105 (the ADAU1701 is generally 0-70). The program can be used universally and other indicators are the same. The ADAU1401 is a complete single-chip system with built-in 28/56-bit DSP, ADC, DAC and microcontroller-like control interface. Signal processing techniques including equalization, crossover, bass boost, multi-band dynamic processing, delay compensation, speaker compensation, and stereo image widening can be used to for the practical limitations of speakers, amplifiers, and listening environments, dramatically improving the sound quality experience. Two ADCs and four DACs provide 98.5 dB of analog input to analog output dynamic range. Seamless connection to other ADCs and DACs is possible with digital input and output ports. The ADAU1401 communicates over an I2C bus or a four-wire SPI port. The ADAU1401 program can be loaded from the EEPROM through its self-booting mechanism at power-up or from an external microcontroller. When turned off, the current state of the parameter can be written back to the EEPROM from the ADAU1401 to be recalled the next time the program is run. It has self-starting after power-on and can be completely separated from the single-chip operation. Leads to all function ports, which can expand digital I2S input/output/key function/LED drive/auxiliary ADC (potentiometer analog)/encoder volume adjustment.