This LED matrix is a heart shaped badge with circuit which you can make and gift to your valentine or crush and spread your love. It can be worn as a necklace or as a badge.

It has got Bluetooth so you can display any text message on the necklace using a smart phone.

https://hackaday.io/project/114144-led-ble-hearty-necklacebadge

Joe says: "This is very involved, but very creative too, it's worth reading if you are technically minded".