This week:
I encountered several challenges while debugging the Sensor Matrix. After identifying and fixing a short in the mux-select lines and re-wiring, I individually tested all the PCBs, which showed promising results. Callum revised the heatmap code to include interpolation. However, when I assembled the components together, the accuracy plummeted by about 80%, and visibility at most locations was severely compromised. Despite functioning perfectly outside the circuit, the components failed to perform once integrated. Additionally, the sensitivity of the hall sensors significantly decreased.
In response to these issues, I ordered new digital hall sensors to see if they might help resolve any of the ongoing problems. To troubleshoot further, I initially reduced the polling rate, using the Arduino’s baud rate to control sensor queries for real-time imaging. This adjustment, aimed at minimizing potential interference from rapid mux switching, unfortunately did not resolve the issues.
I then examined the Arduino’s power supply, suspecting that high system impedance might be dampening sensor sensitivity. By connecting the matrix to an external power source and unifying all GND pins, I tried to enhance performance by cautiously increasing the voltage while maintaining low current compliance—yet this approach also fell short.
However, a breakthrough occurred after a revelatory dream prompted me to adjust the current compliance in tandem with the voltage increase, despite the Arduino not being directly powered by the current. This adjustment proved successful, though the reasons behind its efficacy remain unclear, particularly since the system’s operation isn’t reliant on current. I plan to further investigate this anomaly. This solution did introduce some additional noise, which I intend to mitigate by soldering larger capacitors onto the power lines.
Moving forward, the matrix will be powered externally, ensuring optimal voltage and current levels. Luca has already procured the necessary supplies, and I will maintain a unified ground across the system. I am also experimenting with Op-Amp resistance values to potentially enhance amplification.
Schedule update:
Despite a slight delay due to these troubleshooting efforts, I am close to being back on track.
Next week’s agenda:
– Test the new digital Hall Sensors to determine if they address the matrix issues.
– Continue adjusting resistor values for the Op-Amp.
– Solder larger capacitors onto the power lines.
– Secure wiring and integrate with DC power supplies.
– Assist Luca with mounting the sensor matrix.
– Support Callum in developing the FSM for the system.
– Prepare for the Final Poster and Demo.