EE193 Networked Embedded Systems Final Project: Campus-Wide Wireless Temperature Monitoring Network

Project Overview

This project, developed as part of an advanced embedded systems course at Tufts University, focuses on designing and deploying a wireless network of temperature monitoring probes across campus. The network collects and transmits ambient temperature data in real-time, supporting environmental and facility management efforts. Key project highlights include scalability, low-cost design, and robust performance in varying environmental conditions.

Features

• Data Collection: Hourly temperature measurements with timestamps accurate to within five minutes.
• Precision: Readings accurate to within ±2°F.
• Data Transmission: MQTT protocol ensures efficient and reliable communication with a campus server.
• Power Efficiency: Probes operate autonomously for up to six months on a LiPo battery.
• Environmental Durability: The system withstands various weather conditions, including rain, ice, and wind.
• Cost-Effective Design: Each unit costs less than $15 to produce at scale (1,000 units).

Technical Highlights

• Microcontroller: ESP32-C3-WROOM module for low power consumption and WiFi capability.
• Sensor: PCT2075DP,118 temperature sensor for high accuracy and low energy usage.
• Custom PCBs: Designed using KiCAD for compact integration and efficient performance.
• Software: ESP-IDF framework and Arduino were used for programming, with MQTT and WiFi functionalities implemented.
• Dashboard: A custom-built web interface for real-time data visualization and analysis.

Deployment

Three nodes were deployed across the Tufts Medford/Somerville campus. These 3 nodes were operational from May 2024 to January 2025. Unfortunately, as of January 2025, they have been removed by Tufts and are no longer operational.

Lessons Learned & Future Improvements

• Lessons Learned:
  • Ensure compatibility of programming boards with microcontrollers.
  • Perform continuity tests on all boards before use.
• Potential Improvements:
  • Transition from LiPo batteries to solar panels for eco-friendly, self-sustaining power.
  • Explore alternative sensors and ESP modules to further enhance power efficiency.

Repository Content & Helpful Links

• Writeup: For a detailed writeup of this project, including pictures of our KiCAD schematics and snippets of code, visit this link: https://www.notion.so/lindazhao/Team-Fire-Nation-Final-Report-dc0f7105e2b34866ada27040306ecb55?pvs=4.
• Schematics and PCB Layouts: A KiCAD zip folder of everything can be found here: https://drive.google.com/file/d/1rzjhcRprmjvbViDM0Jm00A539Co3ytU3/view?usp=sharing.
• BOM: We were the only team who managed to get within $5 of the goal cost of $15. Our BOM can be found at this link: https://docs.google.com/spreadsheets/d/19IVyPjfXpfomtAPkblObAk700TYVvV6gad1exjRFkIU/edit?usp=sharing.
• Code: Source code for ESP32 nodes, including MQTT and WiFi functionalities, can be found in the src directory in our main branch.
• Arduino Test Code: We had trouble implementing our project with the espressidf code at first, so we tested functionality of our hardware and simulated a working sensor with the Arduino code found at this link: https://github.com/gmbeddard/TeamF_Final_Arduino.
• Dashboard: Interface designs and implementations are located in on my teammate Linda's Github at https://github.com/lindazha0/dashboard-server.
• Programming/Debugger Boards: We primarily used the Digikey ESP Programmer Board, found at this link: https://www.digikey.com/en/products/detail/espressif-systems/ESP-PROG/10259352?utm_adgroup=&utm_source=google&utm_medium=cpc&utm_campaign=PMax.

Authors

I'd like to thank my lovely teammates on Team Fire Nation: Emily Stanisha (@estanisha) and Chuyi (Linda) Zhao (@lindazha0). Together, we were one of the only teams in EE193 to get all 3 sensors working and recording data.

Thanks for reading!