Carnegie Mellon ECE Capstone, Spring 2025 – Arda Akinci, Rohan Shenoy, Howard Ma
Personal Accomplishment
Next Week Goals:
Status: On Schedule
Team Accomplishments
This week we presented our final presentation to the class including the use case, design decisions, system implementation, and test strategies we used throughout the project. We also ran many tests (up to 20 official tests) to gauge the robustness and accuracy of our system and individual components. We noticed a lot more leakage and spillage than we anticipated during testing, hence we applied a sealage to the valves in order to minimize this risk. Furthermore, we standardized lengths and orientation of pipes in order to get consistent flow rates for easier testing. We also, through trial and error, figured out timings for valves to stay open corresponding to volumes in mL. Furthermore we began working on the poster, completing the pitch, system architecture, system implementation, and testing sections for next week.
Testing
We are currently on schedule
Personal Accomplishment
Testing
Next Week Goals:
Status: On Schedule
Personal Accomplishment
Next Week Goals:
Status: On Schedule
Personal Accomplishments
Learning
Through this experience I learned a lot of hardware in terms of building a robotic arm using Arduino, specifically building and adjusting motors in the arms to gauge physical movement capabilities. I also learned electromagnetic principles in how to operate the stirring of the pill using a magnet and controlling its torque. I also learned how to work with the Arduino IDE altogether including managing multiple ports and interacting with the serial monitor. I also learned how to write Arduino checkpoints and agreements which we used for integration between our various parts. Finally, I learned how to use many of the wood shop tools including a drill hole, table saw, etc. Many of these learning new skills took much time through online videos, consulting my peers, TAs , and professors, but ultimately I learned it the most through experience and everyday putting in the effort to gain and be sufficient in the skills required.
Next Week
Schedule: On time
This week, our team focused on finalizing complete system integration and verifying performance through testing. All subsystems were fully integrated and evaluated with tests that include multiple user input scenarios.
We completed all valve wiring for our six-drink setup and reinforced stability to prepare the system for final presentation and demo. 4 legs were added to the platform for support while freeing up space for hiding and protecting circuitry underneath and improving vertical spacing for fluid flow. We also drilled routing paths for wires and tubing to reduce clutter and providing guided paths for flow. The stirrer was finalized and mounted, providing a fixed, reliable zone for users to place cups.
On the software side, we updated the WebApp styling with custom CSS to improve user experience and performed full testing using the ingredients page, drink product page, and recommendation system with voice input. Across more than 50 test cases, the correct valves fired with 100% accuracy, confirming that our communication protocol and pin mappings are functioning reliably.
Next week, since it’s going to be the final week, we plan to focus on:
Risks and Mitigation
Design Changes
We are currently on schedule.
Personal Accomplishments
Next Week
Schedule: On time
Personal Accomplishments
Scaled out the circuitry to support 6 valves and organized circuitry to make setup easier
Helped organize the tubes and containers by taping the valves to the wood and labeling/mapping ingredients based on our website.
Experimented with different valve pressures and measured amount of liquid dispensed to determine ball park estimate of ratio of timing to amount in ML
Below is the image of attaching the valves to the wood: https://drive.google.com/file/d/1NUxk5qAmYsefShDEVbOFaYRmuMOm26_l/view?usp=sharing
Below is the image of scaling out the circuitry: https://drive.google.com/file/d/1aPcGPDX6_HwjfodIvGQHIX_9pdHxlQD1/view?usp=sharing
Verification
Since I was the lead contributor for the valve dispensing system, my verification and testing was in the form of ensuring certain valves opened according to ingredients chosen. Hence, my testing was experimenting with different combinations of drinks and timing how long the corresponding valves stayed open to ensure the circuitry was correct. Additionally, I testing different valve pressures and found that the pressure of 0.15 Pa was the optimal pressure for our system, I plan on doing more verification to ensure it fits in to the entire system.
Next Week Deliverables
Further testing of the dispensing system and overall system
Build the legs that will hold up the dispensing system and drill holes for the tubes and wiring the go through
Organize the entire system to prep for demo day
Status: On schedule
This week we began optimizing our system to look more visually appealing for the eventual final demo, now that we have a working system end to end. We began by shortening the pipes and taping the valves to our wooden structure so that the flow rate is consistent and the dispensing system looks cleaner. We also scaled out to 6 bottles and numbered them in certain positions on the dispensing unit that map directly with the website ingredients. Additionally, we improved the AI recommendation service to fully output customize drinks based on variety of user input and added in a “fun fact” which is additional information on the drink being made. Furthermore, we printed out the platform that the cup will sit on and the stirring mechanism will rest beneath. Finally, we scaled out the circuitry that attaches to each valve such that now we can control 6 different solenoids related to the 6 ingredients.
Below is the image of attaching the valves to the wood: https://drive.google.com/file/d/1NUxk5qAmYsefShDEVbOFaYRmuMOm26_l/view?usp=sharing
Below is the image of scaling out the circuitry: https://drive.google.com/file/d/1aPcGPDX6_HwjfodIvGQHIX_9pdHxlQD1/view?usp=sharing
Below is the full image of all valves attached to the system: https://drive.google.com/file/d/1G9PB19FqwNt-jJ9HlFJwAHforfFz5lIG/view?usp=sharing
Verification and Validation
In terms of testing the dispensing system, we are currently in the process of testing amount of mL dispensed and mapping it to timings the valves are open to ensure the right amount of each ingredient is poured. We are testing this by individually measuring dispensing amounts using a measuring cylinder and currently experimented with two different valve pressures to determine which one gives a steady and reliable flow. We also are planning to run several trials to observe and minimize leakage, using specialized safety clamps to observe where leakage is happening and avoid it. Finally, we are planning to do many different combinations of ingredients using the inbuild ingredients page and AI recommendation service to ensure certain valves correctly open. We plan on measuring the final amount of product and ensure it matches the sum of the ingredients also using the measuring cylinder.
In terms of the mixing system, it is pretty simple and reliable in its mechanism, so testing will be a series of repetitions in the overall system, ensuring that the pill spins for a certain number of revolutions for sufficient mixing. This number will be determined later after several trials of experimentation.
In terms of the garnish system with the robot arm, we currently have it fully integrated with the rest of the system but plan on testing individually to ensure the robot arm can reliably place the garnish in the cup. To do so, we plan on transitioning to the actual garnishes we are going to use for the demo, and test the robot arm on all the different ingredients multiple times, to ensure the robot arm and clamp is configured to pick up these unique shapes.
As a system altogether, we plan on running several tests using different combinations of ingredients, amounts, garnish selections to ensure the robustness of our system. We also plan on experimenting with different orientations to validate the quality of the system in an external enviroment.
Status: On schedule
