Senior Design Lab 1

Introduction

The goal of this lab was to create a “third box” temperature measurement system that could be used independently as well as connected to the internet. The third box is a physically robust device that contains a temperature sensor, a display, a power switch, and a button to turn on the display. It can be used without internet, and the temperature will show on the display. When connected to internet, the temperature can be viewed as a graph on a web app. If the temperature goes above or below a threshold, an SMS alert will be sent to a specified phone number. The SMS alert and number can be changed from the web app.

Design Process

• Attached waterproof temperature sensor to an embedded ESP32 microcontroller to continuously sample temperature
• Used ESP32’s WiFi capabilities to transmit temperature data to the Internet
• Constructed a robust box for the hardware using a Tupperware container
• Displayed temperature data using a liquid crystal display (LCD)
• Implemented a web-based interface to:
  1. display real-time temperature and a graph of temperatures for the past 300s
  2. remotely turn the LCD screen on/off
  3. automatically send texts when temperature reaches a certain threshold

Figures

Figure 1: A diagram of major subsystems and communications between them

Figure 2: Schematic of circuit design of the third box

Figure 3: The complete project hardware, view of the interior

Report – Code – Web Interface