The Light Dependent Resistor Detection Timer is a portable, battery-operated system that detects when an object is removed from and placed on a surface. The system is intended for use in educational or casual timing applications where portability and independence from wall power are priorities, and is designed so that the vast majority of users can operate it without instructions. The system is built around an ESP32 microcontroller, which coordinates all subsystem blocks. Object detection is achieved using a photoresistor configured in a voltage divider circuit, whose output is read by the ESP32's integrated analog-to-digital converter. When the ADC reading crosses a software-defined threshold indicating the object has been placed, the microcontroller begins its timer routine. If the object is then removed before the timer finishes, an alarm will sound. The information is displayed using an SPI RGB LCD module. The system design allows the user to select three distinct brightness levels by controlling the display's backlight brightness via PWM. Power is supplied by a 9V battery, stepped down to a stable 5V rail through a custom voltage regulator PCB. The most notable accomplishment during this project was component selection and documentation. There are vast numbers of devices on the market, but identifying components with proper datasheets that could interface correctly with one another to achieve our end goal was a significant accomplishment. The main challenge was creating the 3D-printed housing. This required learning CAD software in a short amount of time, which proved difficult. As a result, our housing was lackluster and could have been improved. For example, it would have been nice to design an enclosure that concealed the system's purpose, creating something a user wouldn't immediately recognize as a detection timer.