类型: IC
作者: Bobnaive
发布时间: 2017-08-06
02:20:45
更新时间: 2018-12-08 01:14:21
原链接:
https://geekhack.org/index.php?topic=90938.0
Haus’s USB to USB keyboard converter topic:
https://geekhack.org/index.php?topic=69169.0
Big thanks to him.
So based on Hasu’s schematic
i re-designed this U2U.
i am trying to make the U2U
much smaller.
because each USB port is very close, so
they do not have too much space.
and if the U2U is
small enough we can put it in the keyboard.
As we all
know USB tongue’s thickness is about 2.5mm.
But it is
2.5mm, it will be too tight. so we need reduce the thickness
ASAP.
the 32U4 height is about 0.8mm, and i use 0.4mm
PCB make it as thin as possible.
and i also draw a
shell for it. Use 3D print to make the shell.
but due
to 3D SLA technology, we can only make the thickness no more
less than 0.5mm.
after all, plus all the things the
thickness is around 2.5mm.
and this U2U is too much
small, so i use epoxy resin to combine the PCB and shell.
according
to this small area, i use 0402 resistance and
capacitance.
this is my first version use green PCB.
this coin size is about 25mm
after this, i fix some bugs. and redo the PCB with
Immersion Gold.
it makes USB Gold-finger more reliable,
and black with gold looks better.
this is my final
version.
right now the final size is about 13x27.5x9.5mm.
and
i am not sure the gerber is correct, because i send PCB file
to the factory instead of gerber file.
2018 Dec
upadate
it is been a long time that i did not update
this topic
right now, i made this nano U2U smaller.
the
old one, the size is 12.5 X 28 X 9 mm
the latest one is
14.5 X 23 X 9 mm, 5mm shorter than before. as i know this is
good for cable.
and I removed the switch, but left two
metal contacts instead. I think the frequency of the switch
is not very high once you have done the firmware.
You
can use the dice to short the two contacts to simulate the
switch
this time i use four-layer board. Since I used a
four-layer board, I was able to wire it more easily.
and
put LED on the top, hence you can change the color
easily.
at last, the most important thing the USB
receptacle is soldered on the PCB right now.
it make
U2U much more stronger.
The following is a comparison
of old and new
