Portable Temperature Monitor

Overview

A portable temperature-monitoring device built with an Arduino Uno that alerts users when a space leaves a safe temperature range. The system integrates a TMP36 analog temperature sensor, LCD readout, LEDs, and a piezo buzzer to provide clear audible and visual warnings. Designed with both battery and wall-power options, the enclosure uses a custom ABS housing with internal wiring optimized for reliability and serviceability.

Technologies Used

• Electronics: Arduino Uno, TMP36 sensor, LEDs, piezo buzzer
• CAD: Custom ABS enclosure, laser-cut mounting plate
• Programming: Arduino C++ (I2C LCD, ADC sampling, PWM tone generation)
• Manufacturing: Soldering, heat-shrink, custom wiring harness (22 AWG)

Key Features

• Safe-range monitoring for rooms, labs, or storage spaces
• Live temperature display in Fahrenheit
• Red LED and buzzer alerts when temperature exceeds limits
• Dual-power support: 9V battery or USB / barrel jack
• ~125 hours of battery life

Contributions

I designed the full system, including electrical wiring, mechanical enclosure, component integration, and firmware. This involved calculating safe LED current limits, designing the power budget, creating enclosure CAD, and writing Arduino code to sample the TMP36, convert readings to Fahrenheit, and trigger alerts.

Challenges

The main challenges were packaging the system cleanly inside the enclosure and managing wiring so components remained serviceable. Ensuring accurate ADC readings from the temperature sensor also required careful grounding and layout decisions. Future improvements include migrating to a custom PCB and improving cable management.

Designed for EK131 during my first semester @ Boston University

Other Photos

Internals of final product