Ten years ago, I had a $2 top with LED lights which cleverly displayed words in ... | Hacker News

Hacker Newsnew | past | comments | ask | show | jobs | submit

		mhb on Jan 15, 2012 \| parent \| context \| favorite \| on: Military technology: Magic bullets Ten years ago, I had a $2 top with LED lights which cleverly displayed words in a fixed position by using a sensor to use the earth's magnetic field as a reference.

joezydeco on Jan 16, 2012 [–]

If the top cost $2, it probably was not a magnetometer clocking the LEDs in that toy.

Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact