A few months ago, Connor Nishijima demonstrated a neat project highlighting the Arduino Uno’s “built-in motion sensor.” Now, he’s using the Arduino Mega’s “built-in anti-GPS” to guess which countries you’re NOT in. How, you ask? By reading the frequency of the alternating current (AC) cycles in his house using an open analog pin.
You’ll need an Arduino Mega to fit the array of Strings below, Uno doesn’t cut it even with use of PROGMEM. The Sketch is also written to use the Seeed Studio TFT Shield, but if you remove all “TFT” lines from the sketch you can just see the output in the Serial Monitor. An antenna (just a breadboard jumper) on A7 might be necessary.
Since various locations have varying power systems, Nishijima was able to program the board with a list of all those that cycle the AC at 60Hz and 50Hz AC. By knowing which one you have, the Arduino can then reckon which countries you’re not in and display its findings on the TFT shield.