[Arm-netbook] laptop and microdesktop pcbs

Luke Kenneth Casson Leighton lkcl at lkcl.net
Sat Oct 3 12:08:59 BST 2015


ok so:

after finding that there's someone who is maintaining an STM32F072 USB
branch, and testing it successfully to create both a usb-hid and
usb-cdcacm example i put the majority of the components on the laptop
STM32F072 PCB, with the exception of the 3.3v regulator which isn't
here yet.  i have a source of 3.3v power so that can be tested later.
assembly of the much smaller STM32F072 PCB was only a day, with two
uses of the IRDA lamp.  i did however have to go round all of the
0.5mm pitch QFP and FFC pins individually with a soldering iron.
surprisingly, QFNs tend to stick first time.

i've also ordered the laptop PCB3 which is the power board, that one
is going to be fun and games, especially with the EMF from the rather
large (4A) regulator.  i've put in a huge number of GND vias
surrounding the high-frequency power output which goes to the
inductor, we'll just have to see what happens.

also i had redesigned the microdesktop board some weeks back, and will
be de-populating one of the existing boards and transferring all the
components.  this i anticipate to be pretty straightforward, although
perplexingly the microdesktop board has a staggering 120 components.
i don't quite understand why, given that it's 4in x 3.5in and that the
CPU Card itself is around 3.5in x 2in!  still, there we go... :)

l.



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