Using I2S and PDM simultaneously for an audio measurement device
Posted: Sat Oct 15, 2022 3:31 pm
Hey everyone,
I want to design an ESP32 based, fully digital audio measurement system (SPL, frequency response, speaker impedance, THD etc.).
My plan is to connect the ESP32 to an I2S audio amplifier (TI TAS5805). The output signal is routed to the speaker and with resistor dividers back to an audio ADC (Cirrus WM8782) that returns the signal back to the ESP32, for impedance measurements and measurement of the output level (for calibrated SPL).
At the same time, acoustic data is measured with two MEMS microphones with PDM interface.
Even though the single measurements are only a few seconds in duration, the incoming data would probably be too much to fit in the RAM, so there's also a microSD card connected via SPI to buffer the incoming data.
My question is: Is the ESP32 able to handle I2S with 24bits and 48kHz (or better 96kHz) and stereo PDM with >4MHz at the same time?
Is it also possible to simultaneously buffer the incoming data on a SPI flash?
Best regards,
Bastian
I want to design an ESP32 based, fully digital audio measurement system (SPL, frequency response, speaker impedance, THD etc.).
My plan is to connect the ESP32 to an I2S audio amplifier (TI TAS5805). The output signal is routed to the speaker and with resistor dividers back to an audio ADC (Cirrus WM8782) that returns the signal back to the ESP32, for impedance measurements and measurement of the output level (for calibrated SPL).
At the same time, acoustic data is measured with two MEMS microphones with PDM interface.
Even though the single measurements are only a few seconds in duration, the incoming data would probably be too much to fit in the RAM, so there's also a microSD card connected via SPI to buffer the incoming data.
My question is: Is the ESP32 able to handle I2S with 24bits and 48kHz (or better 96kHz) and stereo PDM with >4MHz at the same time?
Is it also possible to simultaneously buffer the incoming data on a SPI flash?
Best regards,
Bastian