Highlight

Essential technique points used in this project.

PWM PIO Module

The reason why we used the PIO modules to implement the PWM function rather than other functions is straightforward and simple:
Most I/O functions would be using the PWM modules as vehicles.
PIO, an independent hardware module on RP2040, would be much more efficient when compared with GPIO to control the I/O stream. Music play and instrumental sound generation would be possible using the PIO module without initializing and utilizing more GPIO functions. The responsibility of the PIO PWM module, based on our function design and proposal, would be generating the PWM signal to convey our predefined music in game mode and play specific music notes in digital instrument mode.

Flash Memory Storage

Only playing impromptu music is not that exciting. What people really like is long-standing memory. Thus, with the need to store impromptu music playing under the instrument mode, we need to find a storage medium to save these precious records.

Several options are available to us: using an external storage medium, for example, an SD card, using the integrated memory, for example, the flash memory in RP2040, or saving data to another chip or connected PC. The shortcoming and advantages of these methods are obvious. Using an SD card is convenient, but it takes some extra budget, and more time should be put into the FAT32 driver for SD cards. Using the built-in flash memory would be easy to implement and completely at no cost, while the storage space is strictly limited. Saving data to an external device is also of no cost while also having few limitations of amounts of space, but not profitable.

The last decision is to use flash memory as the storage medium, which is of no cost. Since the audio data is not as large as images and video, the storage space limitation is not that severe.

Multicore Function

Considering the essence of the music game is the music played in the background, we would like to play the music when interacting with gamers in the game. Fortunately, RP2040 has two cores, which means it can handle two tasks at the same time. We adopt the multicore function in the SDK and use two threads to implement our music game.