This application is written mainly in C (and little of C++). This application is built using the port audio library.
It has two modes of operation:
- Visual mode
- Audio mode
In visual mode, you select the target note by clicking the button.
The notes are cycled every button click.
In visual mode, the audio is recorded from mic and estimation is made
and closest frequency is matched and the back light changes to green
from red when the target note is matched.
Audio mode is entered by the long press of the button.
In audio mode, piano note as set in visual mode is played continuously
until button is clicked to exit the audio mode.
You can follow this Instructable to build your own.
Here is the video of the device in action: