D7 protects against reverse battery connection. The LEDs are biased to operate at about ... They are both inexpensive and BRIGHT! The 12v battery level indicator unit in the photo has no reverse ...

Here is the circuit of an Arduino-based Panic Alarm! The wiring is very simple so that even a novice can ... You can use any standard 9V battery to power the whole circuit, and the Push-ON (push ‘n’ ...

Makers, developers and hobbyists that enjoy building Arduino ... a battery connector & charger built-in, & a fuel gauge that can tell you when to charge the battery.” • Battery Charger Circuit ...

So, what do you do when your Arduino project needs to operate in a remote area or as a portable device? There are LiPo battery shields ... his build with schematics and lots of photos so that ...