My project is : recording audio (mono 16 bits 44kHz) on a SD card.
IDE = Arduino
1/ using SD.h and SPI.h, I cannot reach a sufficient rate of recording (40kb/s instead of 88, for a theoritical minimum of 25Mb/s for a standard SD card !) The speed is limited by SD Write (32768 bytes buffers).
SPI configuration : what is the maximum SPI clock freq usable with a 32Go SDHC ?; changing this parameter seems having no effect (superseded by SD library ?)
2/ when I add PDM library to get data from the integrated mic, recording on SD stops after some seconds > conflict between SD, SPI and PDM ?
Thanks in advance for your help.