Blog 7 Capstone Project Update

It's showtime!

Spooky weather and stressed engineering students are among us, but that won't scare away our Halloween spirit or our drive to showcase the progress we've made this semester.

Our team has made significant progress on the NASA fuel cell project. We successfully got the heating pad and fan operational and have received all necessary machined parts from our machinist. Notably, the thermistors now fit snugly into the designated slots on the top and bottom aluminum slides, matching the outlined design. During a recent demo with Professor Agrawal, we were pleased to hear he was satisfied with our progress, although we raised some concerns. Specifically, we discussed the challenge of integrating code to collect data from both the thermistors and the fan simultaneously. Additionally, we’ll need to create a voltage divider to manage power from the wall outlet, which will allow it to be compared to a square wave signal. This step is crucial for getting accurate wattage values from the heating pad to calibrate thermistors and fan. Another upcoming task involves measuring the resistance curve of the heating pad as it heats and cools, with readings recorded using a multimeter.

In terms of completed tasks, we’ve successfully met our demo requirements and addressed significant technical challenges. Moving forward, our next tasks will focus on initializing testing to ensure seamless data integration and completing the voltage adjustments. 

For the work period of October 13 - November 9, our team's plan for near-term work is to focus on finalizing assembly of the physical prototype, which is a critical step in our project's progression. Simultaneously, we will address and resolve the discrepancies in our circuit control code, specifically looping errors within the Arduino code for the integrated thermistor fan circuit, ensuring its proper functionality. A key aspect of our validation plan hinges on successfully implementing pulse width modulation as the control mechanism for our heating pad. This particular task is of the utmost importance, and will be our other main focus besides the code discrepancies.

Our team has recently reached a significant milestone with the completion of our demo, marking the final phase of the Fabrication and Assembly stage. As we transition into the Device Validation milestone, our current efforts are concentrated on finalizing the operation of our heating pad. This step represents the initial testing phase of our completed prototype and sets the foundation for the comprehensive validation procedures we’ve designed to follow.

Over the next two weeks, our team anticipates potential challenges as we transition from fabrication to refining the Arduino code that controls the thermistors, fan, and heating pad. While we have successfully developed individual code segments for the thermistors and fan, integrating these into a single code has revealed looping errors that prevent the system from running smoothly. To address this, we are evaluating various strategies to resolve these loop conflicts and ensure synchronized operation across components. Additionally, we are working on implementing pulse width modulation (PWM) for the heating pad, a critical step for beginning the validation phase, as it serves as our device’s primary validation tool. To ensure continued progress, we are also developing alternative coding approaches and considering backup plans, including breaking down the code into modular components to troubleshoot issues effectively.

Figure 1: Images provided by the machinist, illustrating the progress of the machined part prior to delivery. 

Figure 2: The left section shows the encapsulation of the device's upper portion. In the center are the aluminum plates, each with a thermistor housed in its machined slot. The right section displays the fan component. 

Figure 3: The fan and thermistor wiring emerging from their respective ports, as secured by the plate and enclosure. 

Figure 4: Circuitry setup and testing of the two thermistor readings. 

Figure 5: Team 3 during the component testing, from left to right: Adam, Dominic, Diana, and Gerardo.