Share A Light-up LED Heart With Your Valentine

It’s not roses or jewelry, but we hope [Erik]’s light-up USB heart will be appreciated by his significant other. When the two heart pieces come in contact with each other, each side lights up.

[Erik] started his build by cutting two half-heart shaped pieces out of polycarbonate. After drilling a few holes for LEDs and wires, magnets and reed switches were installed along the ‘broken’ side of the heart. Whenever the hearts come in contact with each other, the magnets trip the reed switches and light up both sides of the heart.

There is USB flash drive embedded in each heart half is loaded with a portable Dropbox. When the USB drive is plugged into a computer, the dropbox steps into action and synchronizes the photo album stored in each heart half. No matter how far apart they are, [Erik] and his SO can share pictures through their glowing LED hearts. Not to come off as a hopeless romantic, but this sounds like something we’d like for Valentine’s day. We’re hoping [Erik]’s SO thinks that as well.

Valentine’s Gift Counts The Days Spent Together

[Vegard Paulsen] dug deep down to the romantic geek at his core and built this box that counts the days he’s spent together with his Valentine. As you can see, it uses a four-digit seven segment display installed in the lid of a wooden box. An Arduino mini is responsible for driving the display, but as you might already know, to keep accurate time you’re going to need a reliable clock source. Instead of using a temperature compensated crystal oscillator like the ChronoDot he decided to pull time data from the Internet via a pair of RF modules.

His closing comments mention that this display will only work for around 27 years but he figures he can always build a bigger display. We’d keep this around, physically unaltered for sentimental value, but switch to a hexadecimal readout to track just over 179 years. Maybe that’s a bit too geeky.

Temperature Sensing Munny


Here’s another nerdy present that was built for Valentine’s Day. [João Silva] created a temperature sensing Munny. A Munny is a vinyl toy made to be customized. Other than these Munny speakers, we haven’t seen them in many electronics projects. The LM35CZ temperature sensor has an analog output that connects to the ADC on the ATtiny15L. The microcontroller changes the RGB LED’s color based on the temperature: blue for cold, green for comfortable, and red for hot. It only flashes every three minutes to conserve the power in the coin cells. His one-off circuit board also includes an ISP header for programming. The Munny’s head looks like it does a great job diffusing the light.

Flexible Circuit Valentine


[xander] built this LED valentine for his loved one. It’s interesting because he used Pyralux, a flexible circuit board material from DuPont. He describes the consistency as “tough plastic tissue-paper”, but had no trouble using standard toner transfer etching. It has an ATtiny45 microcontroller that pulses the 16 LEDs at an approximation of his heart beat. To avoid soldering a bunch of surface mount resistors, he used two constant current shift registers.