Well, [shabaz] had a great idea: use it as a star map display. The project combines the Arduino, a round TFT, a GPS receiver, and some external flash memory to store data.

Makers, hobbyists and developers that enjoy building projects using the Arduino platform might be interested in this awesome Arduino GPS Map Navigation System which was being built by Kathy Yang.

After learning how to use sim800l module in my previous project, I decided to create a GPS tracker using the Arduino platform. This project combines a SIM800L module for communication and a Ublox ...

But it's possible to go even smaller, as the makers of a new Arduino-compatible product called "Microduino" show. At 1" × 1.1", it's nearly as small as a quarter.

Except, on the Micro, there is no actual serial bus involved in programming the Arduino, as everything is done over USB. So the TX and RX leds are driven by a couple of pins on the ATmega32U4 (see a ...