Beating Heart Headband

• Assemble the Open Heart display.
• Further instructions on the Open Heart documentation page.

Build the Mintduino circuit on the enclosed solderless breadboard to start out, and fire up the Open Heart test code.

• Add the pulse sensor, load the headband's Arduino sketch onto the microcontroller, and test the sensor.
• Be sure not to pinch the connectors on the back of the sensor's circuit board, just touch the side with the heart.

• Dry fit the components onto a piece of perfboard.
• Fit the heart display over the components, and mark the component layout with a marker.

• Trim the circuit board to fit behind the heart display with a pair of shears.
• Double check the fit by pairing the board with the display.
• File the edges of the fiberglass perfboard to be smooth.
• Wear a dusk mask!

Solder up the components of the perfboard Arduino, using component leads and small bits of wire to make connections as necessary.

• Headband time! Measure around the circumference of your head, then cut two pieces of ribbon to that length.
• Thanks to Britex Fabrics for supplying the beautiful brocade and grosgrain ribbon for this project!

• Cut a piece of cord elastic about six inches long.
• Tie the ends together in a square knot to make a loop of elastic.

Line up the ribbons and use a zigzag stitch along the sides, but only sew together the ends of the ribbons, leaving the middle section open as shown.

• We'll connect the ends of the ribbon with the elastic to form the headband.
• Fold and pin the ribbon ends to enclose the raw edge, and sandwich one side of the elastic loop in the fold.
• Use this seam to hide the knot in the elastic.

• Stitch the ribbon seam around the elastic and repeat on the other side.
• Now the headband is stretchy where it needs to be, and firm everywhere else to support the (non-stretchy) circuit!

• Wire up the sensor and power board and lay the circuit out on the headband to decide where the display will go.
• When you find the spot you like, pierce the heart display's header pins through the outer ribbon of the headband and then through the perfboard. Solder it up.

Stitch the power board in place, keeping in mind where the tiny lithium battery will go.

• Run the sensor out a small opening near the back of the headband, so it can loop around and clip to the ear.
• Stitch down the wires so they stay put inside the headband.

• Use a zigzag stitch to sew the headband shut along the remaining open edges.
• You may have to hand-stitch some spots too tight to get at with the sewing machine.
• Leave an opening near the power board for toggling the power and changing the battery.
• I used snaps to make a recloseable opening so I can show off the circuit.

• Install the battery and turn it on.
• Attach the ear clip to the pulse sensor and try it on!

Clip the sensor to your earlobe.

Congratulations, you're done!