This week marked our interim demo, where we completed our first full system integration. Overall, the demo was quite successful, and we received largely positive feedback from both our instructors and TAs. While the LED display has not yet achieved 3D image rendering and we are not operating at our target RPM, we were still able to present a strong proof of concept. I was honestly surprised by how much we were able to accomplish in time. Andrew and Kendric both put in significant effort to make the interim demo a success.
One major challenge I overcame prior to the demo was getting the hall-effect sensor to work with the Adafruit HUB adapter. Because the adapter occupies all of the Raspberry Pi’s GPIO pins, we needed to route the hall-effect sensor through the HUB itself. Although the adapter supports up to three LED panels and we are only using two, leaving some pins physically available, we initially overlooked an important detail: data direction. LED panels are designed to receive data, while hall-effect sensors transmit data. As a result, when we first connected the sensor to the available GPIO pins, we were unable to read any signal.
After further debugging, we discovered that the Adafruit HUB adapter only supports unidirectional data flow on most pins, with the exception of the SDA and SCL lines. We then rerouted the hall-effect sensor to these pins, allowing proper data transmission back to the Raspberry Pi. Fortunately, this resolved the issue, and we were able to demonstrate a fully functioning hall-effect sensor during the interim demo.
After having a working project for the interim demo, I’m much more confident about where we are in our progress. I feel that we are now back on schedule and in good shape for the final demo.
Next week, I’m planning on working on the Raspberry Pi software to drive images to display as well as preparing final demo logistics.