Seeeduino Stalker v3 is an Arduino compatible main board which has alot of great features. It is an X-Bee carrier board that can use many different X-Bee modules, such as GPS Bee, Bluetooth Bee and Wifi Bee. It has a charger for lithium polymer batteries and manages a solar panel that can be plugged into the board with out any need for extra programming.
It comes with a RTC (Real Time Clock) that will accurately give the time without turning off when power is cut to the board. Data can be stored through the SD card, which acts as a buffer in the event of power loss. The Seeeduino Stalker v3 is very good for applications in an outdoor environment.
Note: The Input/Output ports on the stalker only work at 0~3.3v.