MoteinoMega GPS lowpower GPS shield ~ eagle files - comments please

[gregcope]

Hi All,

So long saga of me making a moteino GPS thing.

I decided to make prototype an Eagle design.  My first.  Comments / feedback please, as I intend to get this one made and try it out.

Files here;
https://github.com/gregcope/ABoatMon/tree/master/eagle

Background
- Uses COTS (adafruit) and Through hole parts as I cannot do SMD ...
- Has a high Ohm voltage divider to measure VCC in a low power way
- Has a p-channel logic level mofet (6020) to drive the GPS, but still allow the VBackup Battery circuit to be powered
- Has a Screw terminal to watch the logic of an exterior switch

Questions;
1. I think the MoteinoMega is upside down
2. Does the logic look right
3. Any obvious errors?
4. Any suggestions on what I can improve?
5. Any suggestions on PCB prototype manufacturer in the UK/EU (I only need a few!) ?

Ta.

[gregcope]

Hi All,

Some overnight thoughts;

0. I have accepted some ERS warnings (NETs that are not connected) and fix some other (missing values)
1. Fixed a layout issue due to wrong ALT GRID settings (doh!...read the instructions Greg)
2. Will add a Sparkfun DRC and run that
3. Check trace and Seperations are at least 10mil
4. Add a GRD pour
5. Upload a new commit.

[gregcope]

Hi,

V0.2...

https://github.com/gregcope/ABoatMon/tree/master/eagle

0. ERS and DRC (Sparkfun Rules) are both clean
1. Layout looks good (to me!)
2. One Copper pour - bottom - as GND
3. I think the trace and seperations are okay ... Advice please?

Will add a silkscreen with some info.  The board is intentionally left large as I am not sure on dimensions, and intend to add parts.

Not sure what to do bar choose a FAB.  Any advice?  I only want one or two.  Quick turn around preferred over saving any £££.  Does not need to be

[Felix]

Separation is OK. I would avoid right angle routing, not really a problem at a few Mhz but a good practice in general.
Your board seems to have a large farm land on the right size, it will really cost you.
You seem to be missing a via in the middle of the board where you route from TOP to BOTTOM, (where yellow X is).
I would add GND pour on TOP as well.
Some DRC errors will only show when the respective layers are visible, beware.
Oshpark if you want speed. PCBs.io is another, I am waiting for my first order from them so any thoughts on them are pending.

[gregcope]

Thanks Felix!

I discovered the cost today when I punched some numbers in for quotes... I will be making another version tonight!

[gregcope]

Lots of tweaks later v0.5 on github;

https://github.com/gregcope/ABoatMon/tree/master/eagle

0. Much smaller (some stuff might not fit!)
1. Added a 12/24V Switched VCC from TomS (Thanks Tom)
2. Made some tracks 0.024 for either 5v @500mA or 12/24V

Thanks all.

[gregcope]

Have got to version 0.9!

- Learnt allot about Eagle
- Made a net class for power traces (0.24width) and updated all power nets
- Made it as small as I could
- Bar one Width error (on the top line) which I cannot resolve it passes OSHPark DRC and most of Sparkfun-standard (angles are an issue that I cannot get the Autorouter to sort out).

So think its ready;

Lastest here;
https://github.com/gregcope/ABoatMon/tree/master/eagle

[gregcope]

Can I ask people review my P-channel mosfets (3 of)?

I also looked at reverse polarity protection - so have also added;

• A polyfuse - any ideas?  This is to power a LIPO charger (0.5ma @5V) from a 12-24V regulated input
• A schottky; 1N5819
• Is the poly fuse supposed to be nearer VCC than the schottky?

Does that work?

[Felix]

If this is about schematic, I suggest posting a screenshot of your schematic, makes it easier to review.

[gregcope]

[gregcope]

Ahh... attachment above seems to have worked.

Felix, does that help?

[TomWS]

Greg,
Where does your 5V VCC go?  I only see a switched 12-24V going to a 5V PS (presumably) and 5V VCC going to two connector pins, but nowhere else.
How does your LiPo get charged?

Tom

[gregcope]

Will check but the 5v-vcc comes from the p-mosfet switched regulator.

The 5v goes to a USB plug on the gsm unit, which is also the Lipo charger.

[gregcope]

That circuit is based on your TomS from here;

https://lowpowerlab.com/forum/moteinomega/moteino-mega-and-software-serial/msg7159/#msg7159

[gregcope]

Ordered one from OShpark... hope it works!