Author: aecai

This week, I worked with Ashira on finalizing our Final slides and presented. I also tested with a temporary RPi after ours was damaged. In addition, I debugged the SSH connection issue with the help of a friend, allowing our team to SSH into the RPi and develop more easily. On the hardware side, I discovered that a possible reason our original RPi got fried was due to an improperly soldered ground on our voltage regulator. I resoldered the connections as needed to fix this. I also helped solder the motor driver protoboards and began incremental testing with Ashira—starting with 1, then 2, 3, and 4 motor drivers. Eventually, we got 6 of them to behave as expected.

I made updates to our GUI to improve user experience by allowing some outputs to function concurrently. I also tested the dispensing mechanism and continued integrating our system toward a fully functional vending machine.

Next week, I plan to complete more testing, paint the vending machine, fine-tune functionalities, submit the poster, record the video, finalize the paper, and prepare for the demo.

This week, I mounted the LEDs onto the enclosure and I focused on integrating the motors yet again. Our breadboard had been damaged due to drawing too much current while powering 6 motors, so following a TA’s recommendation, I began soldering 3 of the 6 motor drivers onto protoboards. I started with 1 reference protoboard, tested it to ensure it worked, and then continued with the rest. Ashira and I collaborated to test each motor driver as she helped solder the remaining 3. We carefully measured each driver’s Vref and confirmed that the motors rotated as expected with the code before soldering the voltage regulator. However, once we soldered a protoboard with 2 motor drivers and connected the necessary grounds and voltage lines onto rails on the voltage regulator, the motors stopped working and our RPi would no longer power on.

Unfortunately, these setbacks have caused my progress to fall behind. I’ve requested a replacement RPi so we can restart our work, but in the meantime, we’ll be borrowing one from Professor Benson, so we can continue testing and hopefully get at least a couple of motors running. At this point, we’re scaling back from attempting to run all 6 motors simultaneously, since every attempt to do so seems to result in some form of failure—either to our components or to our power delivery setup.

Next week, my goals are to complete the final presentation and get our hardware environment stable again. It’s been frustrating to hit so many hardware roadblocks, but I’m hoping we can make meaningful progress before the final demo.

As you’ve designed, implemented and debugged your project, what new tools or new knowledge did you find it necessary to learn to be able to accomplish these tasks? What learning strategies did you use to acquire this new knowledge? 

One of the most valuable learning tools for me was video tutorials and community discussion forums, especially the Raspberry Pi Forum. These resources sometimes provided the insight I needed or helped me move our project one step closer to working. In addition, documentation for various components (such as the A4988 motor driver) became a critical resource once I knew how to interpret it properly.

The most important learning strategy I used was refining my research skills. Being able to narrow down what I was looking for—whether it was understanding a motor driver’s pinout or resolving an issue with GPIO behavior—made my problem-solving much more efficient. I also mainly learned by doing: experimenting with the hardware, testing individual components, and learning from trial and error helped solidify the new concepts.

This week, I focused on setting up and testing the passive infrared sensor. I explored multiple approaches to verify its accuracy, but unfortunately, I haven’t fully resolved the issue yet. Initially, I connected the sensor directly to the GPIO pins and printed “detection” based on the PIR’s state. However, this approach produced frequent false positives. In response, I researched alternative methods—experimenting with both the gpiozero and RPi.GPIO libraries, changing conditionals, sensitivity and timeout parameters, and even incorporating a LED diode that lights up upon detection. Despite these efforts, the false positives persisted regardless of how much I changed it. I suspect the issue may be related to the sensor’s sensitivity and timing, which I plan to debug further.

Outside of the PIR, I successfully helped Ashira get the speakers to produce sound by adjusting the wiring—this involved some frustrating debugging, but we eventually resolved it. I also assisted David with the motors by suggesting that lowering the Vref on the motor drivers could help achieve the expected rotation, which thankfully worked. Additionally, I reorganized the motor circuitry, consolidating it from 3 breadboards to 1 with Ashira.

Although I’m currently a bit behind schedule due to the PIR sensor not being integrated yet, I plan to go into the lab tomorrow to continue debugging. Hopefully, by next week, motion detection will be more reliable and we can move forward with integration.

What did you personally accomplish this week on the project? Give files or photos that demonstrate your progress. Prove to the reader that you put sufficient effort into the project over the course of the week (12+ hours).

This week, I completed the ethics assignment and collaborated with my team to draft the group collaboration section. Additionally, I acted on feedback from our weekly meeting, particularly condensing our talking points into concise notes, such as further justifying our product’s size by researching and documenting studies that support ergonomic factors of our design. I also assisted Ashira with laser cutting and assembling parts of the physical enclosure. Besides this, I upgraded the RPi, installed necessary dependencies, and uploaded the GUI code to test its functionality. This test revealed that I need to adjust the display configuration as I encountered issues with the screen orientation and parts of the interface being cut off, so I also spent some time trying to fix these issues.  Additionally, I tried to help David on debugging the motor control system to ensure the team stays on track.

Is your progress on schedule or behind? If you are behind, what actions will be taken to catch up to the project schedule?

My progress is on schedule.

What deliverables do you hope to complete in the next week?

I hope to properly fit the GUI within the display by updating the current code and have some functioning peripherals.