If he really wanted to "learn to solder", one of the esp8266 devkits from the likes of sparkfun or adafruit would have served him better and been cheaper and less power hungry as well. Running an entire Linux server nonstop just to watch for a button press seems excessive.
Otoh, we've reached the point where you can reasonably run an entire Linux server just to watch a button! Awesome.
Otoh, we've reached the point where you can reasonably run an entire Linux server just to watch a button! Awesome.