solo-hw
solo-hw copied to clipboard
solokeys
Invalid USB plug traces
Hi!
In USB-A_schematic.pdf there seems to be a typo in USB plug traces. Signal wires should be alternate to power, not adjacent.
Is: 5V, D+, D-, GND.
Should be: 5V, D-, D+, GND.
Details:
I think this is more a personal preference. Also usually the supply rails are on the top and GND on the bottom, but again, I don't think they strictly need to follow the physical layout as long as the logical/net list layout is correct.
The problem I can see is that the USB connector has no GND connection?!?
I believe the order of the pins was just the order of the symbol I copied from the eagle library. Yeah no ground connection, I add it with a pour in layout. I switched to this because combining a normal pad and ground plane was a bit problematic. Could also be that I'm very good with Eagle haha.
Having the connection only in the layout but not schematics/netlist is a bit hacky. Why did you need to combine a pad and polygon? A clean footprint should work :)
If I remember correctly, that's what I originally had, but the ground planes didn't "mate" with the ground rectangle nicely, so I switched to this. In other words, I'm bad with Eagle haha.
Now there are no ground planes (because NFC) so it makes even more sense now to fix the footprint haha.
Uhm, the USB-C version has the USB data lines only connected on top, but not bottom layer.
Image from KiCads gerber viewer.
So far I've only seen people using USB data line pads connected on top and bottom, but not only a single one. (e.g. https://www.orcad.com/cn/node/6481, https://e2e.ti.com/support/interface/f/138/t/512449?Type-C-Connector-Layout-Made-easy)
The data lines are also not routed as differential pair. This could be improved. USB FS should not be too picky, but still.
Socket/host-side connectors need to have both top and bottom connected. As a result, the device only needs to connect to one side. Only works since the pins are in the middle.