Ken Shirriff's blog
Rohit Khare stashed this in Hacking
Source: http://www.righto.com/
Stashed in: History of Tech!
To save this post, select a stash from drop-down menu or type in a new one:
There's more to the Magsafe charger connector than you might expect. The center pin of the connector - the adapter sense pin - controls a tiny chip that both identifies the charger and controls the status LED. It is part of a complex interaction between the charger and the Mac. Using an Arduino microcontroller, this chip can be accessed and controlled using the 1-Wire protocol. Is this useful? Not really, but hopefully you found it interesting.
Yes. Hella cool.
12:32 PM Jul 17 2013