Raspberry pi based custom detection timer with touchscreen user interface, object detection, accurate timer tracking, enclosed in a custom designed housing. The Custom Detection Timer (CDT) is a fully enclosed, easy to use timer system that stops counting down when an object is removed from a specific spot. It’s designed for use in labs, workbenches, or training environments where users need a timed alert after taking something away, like a tool, cellphone, or container. Users can control the timer (from 1-20 minutes) by tapping the respective "+", "-" buttons to increment/decrement the timer. Brightness and volume of the alarm can also be adjusted in this manner with other buttons. Once the timer is set, if the object is detected the timer counts down. If the object is removed the timer pauses with 1 second accuracy, and begins to play the alarm tone. Placing the object back over the sensor will resume and stop the alarm. The system is powered by a Raspberry Pi 4, which reads input from a photoresistor. In addition the Pi outputs audio to an custom amplifier and 2-inch speaker via audio jack. To keep the system safe and portable, it runs on a 5V USB-C power supply with a switch built into the cable. All the electronics are stored inside a custom 3D-printed plastic case with openings for the screen, power, and ventilation. The enclosure includes vents for airflow and uses wooden dowels so it can be opened and closed without screws or tools. Once the countdown finishes, the alarm sounds so users don’t miss the alert. The CDT can be reset and used again right away. We worked hard to make sure everything fit well and worked together. We had to reprint the enclosure a few times to get the ports and screen to fit correctly. If we had more time, we would add extra features like a count-up mode and more ways to show time progress with lights or a display.