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newaetech / sonata-pcb

Design files and associated documentation for Sonata PCB, part of the Sunburst Project
Apache License 2.0
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0.8pcb - PUDC floating #15

Open colinoflynn opened 7 months ago

colinoflynn commented 7 months ago

Presumably at some point PUDC got pin-swapped and no longer has it's pull resistor. Either way production mod can easily make this a pull-down, which should mean weak pull-ups on all FPGA pins.

colinoflynn commented 7 months ago

Marking fixedinrepo as mod documented on schematic, haven't updated PCB yet until we get a proper 0.9

colinoflynn commented 7 months ago

The fix is soldering a resistor between pin 22 of the R-Pi header & the GND pin next to it: image image

colinoflynn commented 4 months ago

This is now fixed in latest rev (0.9), default is now a pull-up on PUDC which disables pull-ups on I/O pins. But both are available so we can change the default back to this behavior.