At the University of Arizona College of Engineering, students in most departments are required to take part in a year-long senior design course and project. I lucked out and got an excellent sponsor, mentor, and team, and together we created a Capacitive Volume Sensor for Roche Tissue Diagnostics. While unresolved issues with the design of the electrodes prevented us from meeting our system requirements, I'm still pretty proud of the overall design of the system, and it seems the judges felt the same way.
As to the technical aspects of the system, for which I was largely responsible:
The CVS controller is based on a Microchip PIC32MK GP microcontroller, connected to a TI FDC1004 (or in an alternate design, FDC2214) capacitive sensing IC, which in turn is connected to four sensor electrodes. The PIC32 configures the FDC1004, collects and transforms capacitance measurements, and reads out liquid level data over USB, as well as a 0-5V analog output. The entire system is self-contained on a flexible PCB assembly, which is adhesive backed, allowing it to be installed directly on the reagent tank like a big sticker.
Chandler Gillette (CAD, administrative assistance)
Alana Gonzales (GUI development, admin. assistance)
Lindsay Pruitt (capacitor simulation, admin. assistance)
James Rowley (hardware design, board layout, firmware development, testing)
Paul Udorvich (electrode layout, testing)
Christine Wiltbank (team leader, additional testing)
2020 Craig M. Berge Design Day - "Best Overall Project"
2020 Craig M. Berge Design Day - "Best Presentation"