I am building an android application to generate signals like Sine, Square, Sawtooth and DC. I have been able generate sine,sqaure and sawtooth waves by generating values and filling these values to the buffer through which I write to audio port using AudioTrack class. For DC I am writing a constant value 1 to the buffer and writing to audio port. But this is not generating any output when I connect mobile to CRO.
After referring few docs, I found that the audio I/O of mobile is designed to pass changing signals only. Can someone elaborate what exactly this means? Why do we have such constraint ?is it because DAC can't convert a constant values to analog ? Thanks in advance.