Mini Electronic Drum Set

PROJECT OVERVIEW

The goal of our final project is to make a mini electronic drum machine with a custom PCB, force sensitive resistors, a speaker, and various other components. The purpose of this project is to create a cute, portable drum set that will spark creativity for anyone anywhere!

PROJECT SCOPE

This project ultimately produces a mini electronic drum machine. It does so with three force sensors, a custom PCB, an MSP432, a logic level convereter, and a UART speaker. The three force sensors will connect to our custom PCB. This PCB is then connected to the MSP432. The MSP432 will be connected to the Arduino, that is connected to the UART speaker; therefore, the Arduino acts as a communicator between the MSP432 and the UART speaker. We will be leveraging the UART driver for the communication between the arduino and the UART speaker. For the communication between the MSP432 and the arduino, we will have to create our own driver. This was a reasonably sized project for our abilities and time constraints!

FUNCTIONAL BLOCK DIAGRAM

WIRING DIAGRAM

FULL PROJECT SCHEMATIC

Parts: MSP432, Force Sensitive Resistors, Resistors, UART speaker, Logic Level Converter, Speaker Output

PCB SCHEMATIC

PCB LAYOUT

FABRICATED PCB

PIN MAP

SOFTWARE DIAGRAM

BILL OF MATERIALS

INVENTORY TRACKING TABLE

TRADE STUDY

Criteria:

Functionality - 100% importance

Cost - 75% importance

Complicatedness - 50% importance

Size - 25% importance

There were a few different ways we could have approached this project; we were considering using buttons instead of force resistive sensors, trying to decide the best size for our drum set, and choosing the best way to use the speaker. Ultimately, though buttons were cheaper, we chose to use the force resistive sensors to be able to alter the volume of the drum sounds, then chose to use a smaller drum set to be able to use less materials and smaller parts to keep the project cheaper, and decided to use a specific UART speaker we found online to be easier to use with the UART communication system.

THEORETICAL ANALYSIS

First, we need to put together all of the parts that are needed for this project. Next, once we have all the components, we have to order each part, to guarantee that it will come in time to test! While we wait for the parts to come, we need to begin coding our project and making our new PCB. We will need to figure out a way to communicate each sensor to the PCB, which is also communicating to the MSP432 and the speaker. Then, we must 3D print and laser cut the actual mini drum set. After all of this, we have to put all of the components together and test our project in order to find any bugs!

Power Budget

As recommended by the force sensitive resistor datasheet, for our power supply, we will be using a wall charger or charging from a laptop that is 5 volts. We then will use the logic level converter to step down the input voltage to a maximum of 3.3 volts. This is because the MSP432 cannot have more than 3.3 volts of power.

Challenges

Our team faced a few challenges throughout this project. One of the most significant problems was that the components for our project, in which we ordered online, did not come fast enough for us to be able to test them properly. This delayed the production and order of our custom PCB, which of course delayed testing and other last minute tasks. Next time, we would make sure to order our parts as soon as possible, and make sure that shipping will not interfere with the project timeline. Additional challenges included having the ability to change the volume of the drum sound based on the force of the user’s touch. Although this was our original goal, we ended up having to refine the functionality to just play each sound at the same volume, due to the lack of variability in the data sent via UART, as well as the speaker’s maximum volume already being quite low.