This project serves as an easy to use, enclosed, and accurate custom timer. The timer can be used for countdowns up to 59 minutes and 30 seconds and for countdowns as short as 30 seconds, giving it many possible use cases such as timing how long to cook a cake or timing how long to hold an isometric exercise position like a plank. The timer is built with a 7-segment display which shows the countdown in real time as well as a speaker which outputs a non-grating 440 Hz tone once the countdown is finished. The timer has 3 buttons for adding time on 30 second intervals, adjusting the timer's display brightness, and pausing/starting the timer. Along with these the timer also has a dial which can be turned to adjust the speaker's volume and a switch to turn the full system on or off. The project works by being fed 5V into its clearly labeled power ports. From here, a voltage regulator from the MCP1702 family is used to maintain both a 5 volt supply for the arduino in our system and a 3 volt supply for the audio control piece of the timer. The control unit for this project all occurs on an ESP32 microcontroller. The microcontroller uses interrupts to detect button presses while recording when buttons have been previously pressed to compensate for switch bouncing. The microcontroller also uses the Pulse Width Modulation(PWM) channels to create a 440 Hz tone out of a General Purpose Input/Output (GPIO) pin. The ESP32 uses the ctime library to compare seconds and recognize once a second has passed in order to properly update our TM1637 7-segment display used in this project via the TM1637 library commands within Arduino. The majority of the sound system was put onto a PCB, which was designed on KiCad and purchased from OSH Park. The 3 V supply from the voltage regulator is used to power an LM386 audio amplifier, which amplifies the frequency signal sent by the arduino and feeds this amplified signal into an 8 Ohm speaker. The full system is placed in a tupperware container which is lightweight and easy to take on the go. The full system meets IP43 standards and is safe to use. In this project, our greatest difficulties came from designing the enclosure. We gave less time to this segment of the design than we should have, and as such our initial attempt was disorganized. This made small issues we had–most notably a single poorly soldered wire to ground–take hours to find, and caused a lot of headache. In our final product, while we did put a bit more effort into the wire organization and placement of key components, the overall system is still messily put together and would likely be one of the first things we would revise if given the chance. Given more time it would also be a valuable addition to make our system battery powered, as then it would be easier to use outside of a lab room setting. Ultimately, our team is proud of our custom timer project, and all of the hard work which we put into it. To complete this project, we had to collectively learn (among many other things) to program arduinos, to build and purchase PCBs, and how to effectively search for and purchase specific components for our project. The skills that we developed are our greatest accomplishments of the term, as they will be very useful in future design courses. In terms of more ‘tangible’ accomplishments, we were able to overcome our struggles with getting the full system to function as intended. Our timer can accurately countdown, has a dimmable display, can pause and unpause, outputs a frequency of 440 Hz upon countdown completion, and has an adjustable volume.