Good Morning Everyone,
I am moving from Arduino to Teensy 4.0 due to the need for a larger RAM capability. I have seen some forums saying that performing FFT can have some problems on Teensy 4.0 but these posts are probably outdated. The project involves sampling at a Nyquist rate of 60Hz (measuring frequency between 5 and 30Hz at 5Hz intervals) for approximately 30 seconds so 1800 samples per input. In addition, the FFT has to be taken of 2 analogue inputs (3600 samples total) and then their complex ratio must be computed (MouthPressure{Hz}/Flow{Hz}). The values have to be stored until the end of the 40-second measurement and then complex division is performed.

I have watched the video about the Audio library and have seen the example of the FFT code in the file folder. However, I don' know how to get both the imaginary and real components of the sampled signal and how to perform their complex ratio. Also, I was wondering if a Bluetooth module such as the HC-08 can work with Teensy to send this data to an Iphone. Thank you for any help as always, simpler explanations are appreciated as I'm new to this ;