This project is much more involved than my expectation when I was planning up the project. The complexity comes from mainly two aspects:
It is quite complicated to communicate with the audio module on the board using I2C because it involved the a serial audio interface(SAI) in the middle. In addition, the interface uses a lot of the I/O pins that I can connect wires to, so I have to plan my functionalities wisely to prevent any conflicts.
Since there are a lot going on in parallel, I have to set up multiple interrupts and even threads using RTOS to get the code more efficient and cleaner.
In retrospect, I have completed the core functionalities that I planned out - the two ultrasonic sensors can measure two distances and my board is able to convert the distances into a specific pitch. In addition, I have different sets of timbres to choose from.
However, I planned to use the Bluetooth module to create a menu platform where the user can configure this instrument, while now it is only used as a redundant output for demonstration purposes. The sensors are noisier than my expectation, especially when detecting irregular objects like hands.