Just finished my latest project. I have always liked cufflinks, apart from my wedding ring it is the only form of jewellery that I wear.
Inside each cufflink, I have a ATTINY45, a Real Time Clock chip, a couple of resistors and three LEDs. Each cufflink can display a normal UK Traffic light Sequence, a normal UK Pelican Crossing Sequence, the current time, date and even the temperature. All the hardware and software is open source.
The parts were printed.
The plastic connector was a little big (0.25mm), so I needed to sand it down a little othewise I am very happy.