Just thought I'd share a project I worked on recently. I built myself a small GPS to show me speed and heading information. Anyone with basic electronics knowledge could build one themselves. My project writeup is here: mechinations.net/2014/04/07/gps-sailing/
Arduino module become very popular long time ago.
There are many version of Arduino boards and ton of designs.
They simple to use in application, but a bit more involve in software
On other example of more intelligent unit.
www.instructables.com/id/Compact-Arduino-GPS-Speedo-and-more/
That's is close enough,
but sometimes RED is not " + "
and there is different way how to connect batteries.
Lucky we all here we can ask questions instead of blow up things.
...I still occasionally do, but not by accident....faulty components ....
Li-Ion and Li-Po are completly different batteries and there are not interchangeable.
When you replacing a single cell of Li-Ion ....YES you can.
When you replacing 7.2 volts bat. pack...NO ..you can't chain them.
Bat. packs have build in safety features, will not work.
Li-Pos are very different, they can be extremely overloaded for short period
of time. You see on rating label third figure, something like 25C.
Means the battery can by overloaded for short period of time
25 times above rating capacity. "C" capacity.
I check this one for you.
This is a special version of extra tiny board, with some limitations.
Luck of 5Volts on board, there is no USB to program it and also currently
there are no external shields to extend the functions . / shield.... External smart module, typically need 5V /
On the other hand, It is very suitable for portable and special applications.
Beauty is, on board / build in / voltage regulator .
You can directly supply the board from12 volt.
LiPo mentioned are suggestion for portable stuff.
Manual spec.
USB connection off board
3.3V regulator. ....build in
Max 150mA output
Over current protected
Reverse polarity protected
DC input 3.3V up to 12V........... Voltage range for external power supply.