|28|| Portable Bluetooth Music Player
|# Portable Bluetooth Music Player
Arpan Choudhury arpanc2
Joseph Yang josephy2
Robert Conklin rmc2
## Problem :
Current music playback devices are increasing in size to meet the demand for larger and larger screen sizes. Along with this, the weight of these devices is rather large, as a result of using metals and glass to give users a 'premium feel,' and increasing battery size to maximize the charge life of the device. These factors combine to make good smart devices; however, they also lead to bulky/inconvenient device profiles for physical activity, especially activities like running.
## Solution Overview :
A clip-on wireless music player, capable of storing the user's music, and connecting to wireless headphones via Bluetooth while still still being lightweight and convenient to wear while exercising. The music player will use a Cortex-M series microcontroller to interface with a BLE module to communicate with the paired Bluetooth headset, read from flash memory to store and play back audio, and read user input from buttons on the device.
## Solution Components :
### MCU :
For this device, a versatile, low-power, and compact microcontroller is required, as the focus of the project is to design a lightweight, small profile music player. Due to the power-efficient design and low cost of the K32 L2 (K32L2B31VLH0A) MCU, this microcontroller appears to be the current best fit for the design, as it fits all the conditions listed above. Additionally, it has native USB 2.0 support hardware, simplifying the design process, and ensuring that the device will handle USB communication. Along with this, the K32 L2 has a sufficient amount of GPIO pins in addition to the required DMA and I2C connections to handle the flash memory and various peripherals, respectively.
### Bluetooth :
For connectivity to the Bluetooth headphones, a Bluetooth module is required to manage and handle the communication between the headphones and the MCU.
### Memory :
The music player should have enough space so that users can listen to music for the duration of an entire workout. We decided that 2 GB would be a reasonable size for this purpose (roughly 500 songs). While this may be less than the amount of space available on modern smartphones, we only need a few hours of storage capacity at max, and 2 GB is capable of holding significantly more than that.
### Interface :
To reduce weight, size, and cost of production, we decided to use a simple monochrome OLED display and button interface. We can limit pausing, playing, and track selection to to a single button, using double, or triple tapping to skip forward and skip backward respectively. Mapping these functions to the same button would simplify the design, allowing for less space to be used, while still having strong functionality. In addition, there would be power button, to turn on and off the device. Pairing the device could be accomplished using multiple held button presses,
### Battery :
We are planning on using a standard lithium-ion battery and charging system. This is due to the compact and high energy density of these systems, along with the variety of available systems.
### Display :
A small monochrome OLED display, interfacing with the MCU via I2C, allowing for pairing information to be displayed to the user when setting up the Bluetooth connection to a pair of wireless headphones.
## Criterion for Success :
A device capale of receiving and writing audio data to flash memory, and playing back audio from memory via a Bluetooth device. This includes meeting the memory/storage requirements in the design of the device, working user interface to control device, and having electronic components configured compactly enough to fit into a slim exterior profile.