A simple MP3 Player

This project is about making a simple MP3 Player for a person with disabilities or an elderly person suffering dementia. They just want a simple device to play music without complications or a complex user interface.
It is inspired by the commercial MP3 Player manufactured by Relish. The concept behind this is to provide simple controls for someone that finds an ordinary MP3 player to complex to operate. The Relish design separate the manual controls into two area - a simple set of push buttons for the client and a more complex set for the carer. The simple set allows the client to select one of three radio stations (FM or DAB) or alternatively play the MP3 player. The carer can insert the USB uSD drive with MP3 files and configure the three of the simple buttons for particular radio stations. Limitations include there is no feedback on which MP3 is selected for playing.
After the MP3 track is finished playing the next indexed track is played. While it is possible to select the next track it is not possible to select the previous track. The number of push buttons is keep to a minimal.
While the unit is portable it is still bulky and heavy and not suitable for outdoor travel and at $300 it quite expensive.
I wanted to develop a cheaper unit that overcomes some of the limitations and still keep the two regions of controls: one of carer and one for client.
My design will provide only MP3 playing and use only two push buttons for the client. One for playing and the other for stopping the play.
The carer has a wider choice of control and this is mounted on the screen of a small computer based on the M5Stack Core2. Besides play and stop the carer can select previous or next track or can use a slider control on the screen to select a track number. There is feedback on the screen for this.
The client push buttons use a M5STack Dual Button unit and this is connected to the Core2 computer's port B. A Seeed Studio Grove MP3 Player V3 is used for the MP3 operation. It connects to the Core2 port C via a UART interface.
To implement the MP3 controls I had to read and understand the communication protocol of the Grove MP3 unit and this can be accessed via the Seeed Studio website.
Software is developed using the UIFlow IDE on-line at M5Stack's website. The communication protocol is implemented in byte arrays.
Everything works but it would be good to take this further with programmable volume control and feedback about the title of the MP3 song being played. The cost of the package including a Donner portable USB Speaker is $131. Exclude the Donner and it is $71 where a client can use simple earphones with a 3.5mm audio plug and cable.
While I have used the Grove MP3 V3 it is now longer available from the Seeed Studio web store. You will have to purchase V4 and this has a different communications protocol based on "AT" UART packets. I will implement this is a future project and published on TH-cam next week.
This project makes is also suitable as a STEM project where this students can make a simple MP3 player for their grandparents.
Ref:
Grove - MP3 V3 -Music Player ( www.seeedstudi... )
M5Stack Core2 Computer ( shop.m5stack.c... )
Music for demos:
I did not use commercial MP3s: I used both royalty free MP3s or my own music (arranged & produced)
.