Abstract

This application note presents a comprehensive guide on interfacing four synchronous ADCs with a 4-channel serial SPI communication to an MCU/MPU without requiring additional logic. The ADCs are synchronized using a common clock and start-of-conversion signal, along with a shared SDI data line. The captured ADC data from the SDO lines of all four ADCs is simultaneously collected by the microprocessor using the integrated PRU-ICSS peripheral. The MCU efficiently acquires the 4-channel ADC data, which is stored in configurable dual circular buffers, and subsequently performs Fast Fourier Transform (FFT) computations on the acquired data. The resultant outcomes are then transmitted via a Single Pair Ethernet (SPE) connection, utilizing JSON and MQTT protocols for data exchange and communication.