On Thu, Mar 20, 2025 at 07:56 AM, Greg KF5N wrote:
The next step is to investigate boosting the Teensy's GPIO drive strength and bandwidth via software changes.
I'm just wondering if the current design gets all it can from the default driver setting.? My tests show that crosstalk is a problem on the display cable and that modifying the SPI signal order on it more than doubles the allowed cable length.? This requires hand wiring the display with the v12 board, which is impractical. I checked my wiring many times when I tested it before turning on the power.? And I was still worried I'd blow up the display. But this could be easily accommodated in a new board design with a small connector board at the display to reorder the signal properly.
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The SPI traces on the Main board are also routed next to each other.? Rerouting them, if possible, could be another opportunity to reduce crosstalk and possibly simplify the overall design and avoid changing the software.
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Just a few thoughts for consideration in a future board update. ?Perhaps the testing required for these makes them impractical though.? It's probably just easier to boost the signal strength and call it a day.
