Electronics
V1 Design files
- Block diagram
- Schematics PDF version
- Layout PDF version
- PCB production files ZIP file
You can find these files in the Files
section of the Freewatch
project.
You can also find them in the Repository, under the
mcattin_hw_dev
branch -> hw.
This design is Copyright Julian Lewis 2014.
This documentation describes Open Hardware and is licensed under the
CERN OHL v.1.2.
You may redistribute and modify this documentation under the terms of
the
CERN OHL v.1.2.
(https://www.ohwr.org/cernohl). This
documentation is distributed
WITHOUT ANY EXPRESS OR IMPLIED WARRANTY, INCLUDING OF MERCHANTABILITY,
SATISFACTORY QUALITY AND FITNESS FOR A PARTICULAR PURPOSE
Design tools
This electronics design has been made with the KiCad EDA Software
Suite.
KiCad is a Free/Libre Open Source Software Tool which runs on GNU/Linux,
Windows and Apple OS X. It is licensed under the
GPL license.
Component selection
Design reviews
Design notes
GPS passive antenna
GPS RF design guidelines
Low power design
Backlight
Use 0.5 or 1mm plexiglas sheet behind the LCD with four white LEDs.
Here is a cheap plexiglas sheet
supplier:
http://www.plexiglas-shop.com/CH/fr/plexiglas-folie-5m9m5apyxic/plexiglas-folie-blanc-99532-gt-1-0-mm-iqq6a1wurpd~p.html
> Note: After some preliminary tests, it turn out that the plexiglas idea doesn't work well.
Learn more on backlight:
As optical films are hard to get for private customers, using backlight from a broken cellphone display might be an alternative.
Battery life calculation
- http://www.oregonembedded.com/batterycalc.htm
- http://www.csgnetwork.com/batterylifecalc.html
- http://www.ajdesigner.com/phpbatterylife/battery_life_peukert_number_time.php\#ajscroll