Hello there! My idea goes like this: I want to try to record the sound from a microphone (like my voice), to an SD card. I guess I can't expect record it at a sampling rate higher than 8 KHz (due to the timing of the functions). The audio will be stored in a "raw file" (because I don't know how to create the WAVE/RIFF header automatically); and maybe playback that recording with the same board (but that's the "stage two" of my plan). Now here are my questions:
- Shall I need amplification for the microphone's signal, or changing the reference voltage will also help?
- Can an analog input pin handle negative parts of a waveform? I think even a schottky diode will completely kill the input signal.
- Since the recorded samples must be unsigned 8 bit, which of the following is faster? Map the value or shift two bits?
- Would you mind suggest me a way to automatically stop recording? I guess suddenly stop writing to a file without closing it is a bad idea.
Thanks beforehand and sorry if I made misspellings.