MITOS Campus Heat Monitor

The MIT Office of Sustainability (MITOS) Campus Heat Monitor project was the final project for MIT 6.9000 Engineering for Impact.

The aim of the project was to design and manufacture an interactive temperature sensing device capable of monitoring temperatures across the MIT campus as a team of 8 (Team HeatSync!). Some key specifications of the device included:

The ability to operate independent of line voltage
Accurate temperature, humidity, and lux measurements
Status display on an e-paper display
Data posted hourly on a custom website
Storing data locally on communication failure
Weatherproof enclosure

I was primarily responsible for developing the firmware of the device. This included putting the ESP32 SoC to deep-sleep mode to conserve energy, interfacing with the e-paper display and SD card reader via SPI, using watchdogs to prevent the device from turning on for long durations, posting data to the web server, providing support for over-the-air (OTA) updates, and more. The following is the firmware state machine diagram:

6900_firmware

and the final presentation slides:

Source code can be found on GitHub.