Valentine’s Day is nearly here, and for many people, that means getting the traditional gifts of cards, chocolates, flowers, and maybe a night out for dinner. While those are fine gifts, it’s the homemade projects from the heart that will fill others with joy, as they’re personalized and not something that you will find stocked on store shelves. This sentiment is at the heart of being an engineer. Luckily, there’s still time to build that special something for that special someone, as February 14 is still a few weeks away. Below are just a few project build ideas that can be completed before that time, and will surely put a smile on your loved one’s face.

1_open-electronics-heart-throb (Image credit: OpenElectronics via YouTube)

1: OpenElectronics HeartThrob

OpenElectronics’ HeartThrob gadget may seem like any ordinary heart-shaped LED gadget, but there’s more to meets the eye. Not only does HeartThrob light up with different LED patterns when shaken, but it can also be used to play complex light games as well. Inside the 3D printed (PLA) enclosure is a heart-shaped custom PCB packed with 32 LEDs and driven by an Atmel ATtiny85 microcontroller.

Since the chip doesn’t have all the I/O needed to control that many lights, OpenElectronics tasked a TI TLC594016-channel driver to pick up the slack. Powering the HeartThrob is a rechargeable LiPo 3.7V 500mAh battery, which can provide enough juice for 90-minutes of play before needing a recharge.

2: Vegard Paulsen’s Valentineduino

2_valentineduino (Image credit: Vegard Paulsen)

Vegard Paulson’s Valentineduino is a neat device that counts the number of days spent together with your significant other. It’s an easy build that uses a SparkFun 4-digit seven-segmented display (SSD) housed in the lid of a tiny wooden box. An Arduino Pro Mini runs the show with a veroboard to make all the power connections. Keeping time for the Valentineduino was initially done using a pair of RF modules to pull data from the internet, but Vegard has since replaced them with a real-time clock.

3: Rusivan’s DIY LED Heart

3_led-heart-pcb (Image credit: Rusvian via Instructables)

Another great Valentine’s Day project comes from Instructable’s user [Rusvian] with his DIY LED Heart, which he designed using a custom PCB, which features an Atmega8 microcontroller that drives 22 LEDs on an etched PCB. A pair of CR2032, capacitors, and an LM7850 voltage regulator that powers the board, which he then placed within a picture frame with a collage of different images.

4: KodyLab’s Arduino Magic Flowers

4_arduino-magic-flowers (Image credit: KodyLab)

Real flowers are great gifts for any occasion, but Arduino Magic Flowers go beyond simple plants with embedded RGB LEDs that can transition to a host of different colors on demand. KodyLab simple design uses fake flowers with LPD8806 RGB LEDs nestled inside, which are powered by an Arduino. A Sharp GP2Y0A21YK IR proximity sensor changes the color of the LEDs when motion is detected near its location, making for a great display of color.

5: 3D Printed Chocolate Molds

5_3d_printing_hero-heartpops (Image credit: Adafruit)

Adafruit has a great walkthrough that shows those with 3D printers how to create molds you can use to make different shapes out of chocolate, including pixelated hearts. Designs can be made using Autodesk’s 123D Design application to make your own models, or you can import SVG vector artwork instead. Once completed, the models are 3D printed using PLA filament, which is then used to cast a silicone mold. Then it’s merely a matter of melting chocolate, inserting some lollipop sticks, and then letting them cool.

6: Interactive Valentines Box

6_valentine-card-counting-box (Image credit: SparkFun)

Making decorative shoebox containers to hold Valentine’s Day cards is still a tradition in schools and offices. SparkFun blog poster Feldi took the shoebox container to the next level with her Interactive Valentines Box that displays an animation every time a card is received and keeps count of how many are collected. Feldi designed the box by building a circuit using a RedBoard, 7-segmented display, LEDs and an IR transmitter and receiver. As cards or candy travel down a ramp on the inside, the IR transmitter/receiver trips the circuit, which enables the count and LED lights.

7: Valentine Blink: Wireless LED Hearts

7_wireless-led-hearts (Image credit: Adik via Arduino Project Hub)

Arduino Project Hub user [Adik] designed a pair of wireless LED hearts that start ‘beating’ when they come into proximity of each other. His project uses a couple of Arduino Pro Mini 328 boards (one for each heart) to drive a host of Neopixels on custom heart-shaped PCBs that are housed in plastic enclosures. Each heart features an NRF24L01 RF module that communicates with each other when within range, tripping the LEDs to blink in the same fashion.

8: Internet Valentine

8_internet-valentine (Image credit: Becky Stern via Instructables)

Maker Becky Stern designed an exciting Valentine’s project that vibrates a paper tissue heart and flashes an LED when receiving instructions over the internet from a corresponding device. Her IoT Internet Valentine is designed around the ESP8266 Wi-Fi module and uses a pair of push buttons to trigger each action. A vibrating mini disc motor actuates the paper heart, which is also illuminated by a red LED when the ESP8266 catches the corresponding IFTTT gateway service command. Becky created two versions (using the same components) of the Internet Valentine- one encased in a shadowbox frame, and the other in an old Radio Shack project box.

9: Dead Bug Valentine

9_dead-bug-valentine (Image credit: wrightmac via Arduino Project Hub)

[wrightmac’s] Dead Bug Valentine has nothing to do with tiny critters, but an alternative way to solder components together without the use of PCBs. His design features an 8X8 HT16k33 LED Matrix suspended within a wire heart. The matrix is soldered directly to an ATtiny85 microcontroller, which draws its power from a 3.7V LiPo battery that’s hidden in the base of the display covered over by decorative rock. Programming and testing the Dead Bug Valentine is done via Arduino Uno and Genuino Uno respectively.

10: IoT Interactive Valentine’s Day Wreath

10_protocentral-valentines-day-wreath (Image credit: ProtoCentral via YouTube)

ProtoCentral’s IoT-connected Valentine’s Day Wreath responds by beating its LED heart faster and faster the closer a person gets near it, and keeps track of how many people got within range. The design uses ProtoCentral’s Kalam V3 development platform, GPIO Cap, ESP8266 module, VL53L0X laser ToF sensor, and NeoPixel LEDs. The wreath garners information taken from the ToF sensors and uploads it to the cloud in Tweet form with programmed responses, such as “Someone came Close :), or anything else you program into the platform.

The projects listed here are not overly complicated to build if you have some soldering and programming skills. There’s no need to be an expert, but even those with top-tier skills will have fun making these or something original from the heart, and isn’t that what Valentine’s Day is all about?

— Cabe Atwell is an electrical engineer living in the Chicago area.