Hi Nathan, as a new user of Altium I tripped up on a QFN.  Altium vault=20
footprint for it is strictly for automated assembly, the pads for the=20
"pins" stuck out NOT AT ALL from under the chip.  A definite challenge=20
to hand-solder.  So if you used their Vault footprint I strongly suggest=20
editing to ensure the pads come out from under the chip.  I like to have=20
them longer than typical to make my life easier, usually an extra half=20
to whole mm as I recall, the additional pcb space that requires usually=20
isn't at such a premium.

Other comments... if possible a diode for DC polarity protection is=20
worth doing.  Also a cap where the power comes in, 100uF electrolytic=20
etc. space permitting.

Also if possible I always have a LED I can blink with the=20
microcontroller.  You've got all your pins going to headers for external=20
expansion, maybe have one of them go also go to a current limit resistor=20
and then to a LED to ground?  So by removing the resistor that pin can=20
be used for just i/o if needed.  I tend to do away with power-is-on LEDs=20
since the micro will be blinking one, and the situation with power on=20
but microcontroller not running is rare.  (also using a 10K with D1 - I=20
suggest calling it LED1 - may be really dim.)

You'll need fiducials if you plan to have a contract assembler make=20
them, but they'll be panelized for sure, and the fiducials can be=20
outside of the actual pcb and on the panel itself.

Mounting holes?  Even something for a #2 screw could be useful.

Have at least version# in silk, preferably a product/project name too,=20
and preferably your email address too.  I've gotten work because people=20
saw my email in silkscreen... not kidding!

As another person mentioned caps on PGD/PGC shouldn't be there.

Adding a 10K pullup on serial RX means if it is floating you won't be=20
receiving random serial garbage/line noise, which can be a nuisance=20
depending on firmware code and needed functionality.

The Micrel LDOs are nice but expensive.  Microchip MCP1755T-5002E/OT can=20
do 300mA with up to 16V input, there are other variations from=20
Microchip, and nearly $1 less.  I'd have $2K more in my pocket now if I=20
had used them instead of Micrel in a design I did 6 years ago.

have fun!
J




Nathan House wrote:
> Good morning!
>
> I'm a student working on a directed research project involving a PCB desi=
gn
> for a PIC18 microcontroller.
>
> None of my professors have much PCB design experience, so I don't have
> anyone I can go to for feedback on the schematic or layout. I know you're
> all professionals and are busy with your own work, but if anyone has a fe=
w
> free minutes and would like to critique my board layout I would really
> appreciate your advice.
>
> Schematic:
>
> https://www.foxytronics.com/misc/engr495/ENGR495.PDF
>
> Screenshots:
>
> https://www.foxytronics.com/misc/engr495/screenshots/1%20top%20poly.png
> https://www.foxytronics.com/misc/engr495/screenshots/2%20bottom%20poly.pn=
g
> https://www.foxytronics.com/misc/engr495/screenshots/3%20poly%20shelved.p=
ng
> https://www.foxytronics.com/misc/engr495/screenshots/4%203d.png
> https://www.foxytronics.com/misc/engr495/screenshots/5%203d2.png
>
> Altium project:
>
> https://www.foxytronics.com/misc/engr495/ENGR495.zip
>
> I'm planning on inverting the headers on the sides of the board (which ca=
n
> be seen in the last two images) so that it can be plugged into a breadboa=
rd.
>
> I'm trying to learn, so any feedback (I can accept negative feedback!)
> would be greatly appreciated!
>
> Thanks for your time,
>
> Nate
>
> ---
> I'm a college student, take it easy on me ;-)
>
> Check out my small hobby electronics business!
> www.foxytronics.com
>
--=20
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