About the octave error.

[StephenChips]

Hello. I am using your library in my RN project and I find this library will output doubled frequency sometimes. For example when I play A3 (220Hz) on my guitar, it will give me A4 (440Hz) sometimes. Is there a way to eliminate this kind of error?

Since your library is the core of my program, I'd like to collaborate on your project! However since I don't know anything about DSP, I need your aids.