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Project logs / Re: A development board for Lua programming
One point that caught my eye from looking at the boards is the traces to the SDRAM: The trace lengths should match.
Check the JTAG pins (PA13,14,15,P_B_3 (not P_D_3), PB4, don't split those signals to different io headers). Or better: provide footprints for a standard JTAG connector.
USB ports should have transient voltage suppressor (TVS) diodes.
The IO headers should have VCC, GND on the same positions. Maybe GND, VCC, GND starting on pin 1 so that a GND pin could be sacrificed as an index pin when connecting flat ribbon cable connectors (or use double row connectors, which are more common).
Provisions should be made for a 32khz xtal.
Check the space between board edge and io connectors. At least the connector on the long side should be able to be soldered with a 90° pin array to be able to plug it directly into an experimenter's board.
There's plenty of room left, maybe add some "prototyping area" next to the pin rows.