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started pulling parts over to the PCB on the MCP b...
# caravel-board
m
started pulling parts over to the PCB on the MCP based USB board
guess I need to create a footprint for the breakout board mounting
switched some of the parts for availability and footprints to kicad standard
@jeffdi do we want the caravel breakout to be mounted directly using castellated edges or via headers?
j
i primarily wanted a footprint to support direct solder for the caravel board. perhaps it could also use headers if someone wanted to install them instead?
@Passant please see the posts from Michael on this channel. Could you provide an update on what you have completed so far?
p
@Michael Welling hello, I created a footprint for the breakout board where it is just 4 1x14 connectors. I pushed the global symbol and footprint libraries now.
m
Okay I will pull the library and check the footprint
just made a new variant pattern with the outer row being SMT pads so that we can solder the two boards together
image.png
noticed that the pads are not centered on the edges
image.png
image.png
should be ~4.45mm(.175in) from the center of the pad to the edge of the board
p
Please adjust it to be 3.81mm to match the breakout board
image.png
m
I am measuring to the center of the pad
the connector should centered exactly on the edge
p
Oh, sorry, didn't notice that. Yes, to the center it's exactly 4.445mm
m
updated my revised pattern
image.png
guessing we want to break out the remaining pins to headers right?
just noticed that the pin ordering convention is different on the schematic than on the footprint
image.png
image.png
p
Yes I forgot to update the MCP schematic
m
lemme update the symbol
p
The symbol is outdated as well
yes, the last symbol has the right order
m
should I use the symbol from the global library?
image.png
better?
well I have to go for a bit
going to post to a branch on my fork for review
p
@Michael Welling looks good :D
m
something still isn't quite right
20220609_163516.jpg
looks like the pin numbering is wrong
p
I changed the order to be anticlockwise instead of clockwise to ease the routing to the caravel QFN
This is the caravel QFN pin order
m
Okay are we making a different carrier for the different chip types?
Guess I dont have the whole story
@jeffdi see here for context about my concerns
j
@Michael Welling did you ever hear anything else about this?
m
The carrier is the same for different chip types
Just uses a different breakout for each type
The caravel boards repository was updated and the pinout was posted on my Twitter :)
they settled with FTDI for the time being
image.png
image.png
looks like things are different from the last time I saw them
so follow the caravel boards repo and ask @jeffdi and @Passant about what is delivered with what
It might be a good idea to add release tags to the repository such that people don't get too confused as to what they are receiving with each MPW
bundling artifacts (gerbers. schematic) into a zip file for easy access is probably best
so we have an easy to to retrieve the actual files used for for production for each MPW release
looks like for V2 of the breakout they returned to the original breakout pin ordering
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