Just because a couple doesn’t buy into the whole “Hallmark holiday” aspect of Valentine’s Day, doesn’t mean every girl (or boy) doesn’t secretly wish for a little surprise on this particularly loaded day. If you’ve been slacking and have nothing to enthrall your lover, say it’s still a work-in-progress and get your hands dirty making this beating heart headband (or turn in into a tie) via Becky Stern formally of MAKE.
First you’ll need to gather your materials including a Panavise, scissors, sewing machine (or needle and thread), soldering iron, wire cutter/stripper, a Mintronics MintDuino, an Open Heart LED Display Kit, a perfboard, brocade ribbon (or fabric for the headband), elastic cord, and pulse sensor.
Assemble the Open Heart display, by following the directions outlined here.
Build the MintDuino circuit on the enclosed solderless breadboard, and fire up the Open Heart test code. Then add the pulse sensor, load the headband’s Arduino sketch onto the microcontroller, and test the sensor. Make sure not to punch the connectors on the back of the sensor’s circuit board.
Dry fit the components onto a piece of perfboard, place the heart display on top, and mark the component’s layout with a marker.
Put on your dust mask and trim the circuit board so it fits behind the heart display. File the edges of the fiberglass perfboard so they’re smooth. Then solder up the components of the Arduino perfboard.
Measure around the circumference of your head and cut two pieces of ribbon or cloth to that length. Then cut a piece of cord elastic about six inches long and tie the ends in a square knot to make a loop of elastic. Line up the ribbons and use a zigzag stitch to close up the sides, but leave the middle section open.
Connect the ends of the ribbon with the elastic to form the headband, stitching the ribbon seam around the elastic on one side, then repeating on the other.
Wire up the sensor and power board and figure out where you want the sensor. Pierce the heart display’s header pins through the outer ribbon of the headband, through the perfboard, and solder. Stitch the power board in place, keeping in mind where the battery will go.
Run the sensor out the back of the headband and stitch the wires down so they stay in place. Use a zigzag stich to sew the headband shut along the remaining open edges, but leave an opening near the power board so you can change the battery.
Install the battery and turn it on, attach the ear clip to the pulse sensor, clip the sensor to your ear to test, and give away to make someone else’s heart swoon.
Visit the MAKE for further instruction, more detailed photographs and tips on where to buy materials.