Gentle Reminder




Introduction: Gentle Reminder

Welcome to our instructable on how to create a wearable device on your arm that vibrates to remind you of tasks you must accomplish. With buttons that allow you to preset your timer, A Gentle Reminder strives to quietly give you an alert no matter where you may be.

This is a relatively simple project, as the code is already provided and just requires a simple copy and paste into Arduino IDE. Please have it downloaded from prior to beginning the project.

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Step 1: What You Will Need

Feather Arduino 32u4

5.3 x 5.1cm Protoboard : We cut our large protoboard into this size by scoring it with an exactoknife before snapping it


Wires : It’s best to either buy a spool of wire or buy a case of wires of various lengths

3 Buttons

Vibration Motor

Soldering gear

Breadboard : for testing, before beginning construction on your protoboard and plastic tube

LiPo Battery 1200 maH

Electrical Tape

Plastic Tube Guard : We bought our’s from Cut it to 6.6cm in length and cut open lengthwise.

Lycra : Any sort of fabric should do; the important thing is that it’s durable. We chose lycra as its smooth yet slight elasticity aided us in stretching the fabric tightly when wrapping it around the plastic tubing

6.6 x 6.1 cm Piece of Art Board

4.2 x 2.0cm Velcro : We used sticker velcro for our’s, which made application very easy. If you can’t acquire this, sewing on your velcro with a needle and thread will produce a similar effect

Hot Glue and Hot Glue Gun

Belt Strap : Any fabric strap should do; the important thing is that it’s durable and doesn’t rip easily. The one we used was 24 cm by 3.3cm. The width of the belt doesn’t matter, as this would depend on the belt you choose to use. However, the length will vary based on the measurements of your arm. Refer to step one (of the casing) for this.

Black marker

Step 2: Wire the Breadboard

Wire the circuit and electronic components on the breadboard first, based on the image and diagram shown. This is to ensure that all your buttons and LED works before transferring everything onto your protoboard and plastic tube.

Step 3: Test the Code

Load the following code onto the Arduino software:

Then connect the Featherboard to your laptop and upload your code. If it doesn’t work, make sure that “Board: Adafruit Feather 32u4” under “Tools” is selected. Test out the code by pressing onto the button on the furthest left. The light should turn on, followed by the vibration motor going off after 30 seconds. If this does not occur, troubleshoot by making sure that the circuit is wired up correctly, and that all the components are in working condition.

Step 4: Transfer Your Circuit From the Breadboard to the Protoboard

Start off by soldering the header pins to your protoboard to allow for the removal of your Adafruit Feather. Then connect the Ground Pin to both ground lines on the protoboard. Run the pins of each button through the plastic tubing at equidistance and attach a short wire to each end of the buttons. Next connect one leg of each button to the ground line and the other to the pins as shown on the circuit diagram(Pins 12, 11, 10). Then connect push the legs of your LED into the plastic tube on the opposing side to the buttons then connect the long leg of the LED to Pin A5 and the other leg to the ground line. Finally run the wires of the motor through the bottom of the art board, connect the red wire to Pin 13 and the blue wire to ground.

Step 5: For the Outer Casing

Roughly measure the circumference of your arm This will be the length of the belt strap, with the additional number being the length of the velcro you will attach later on. Cut the belt with your new measurements.

Step 6:

Cut the velcro and stick it at the ends of the measured and cut belt. Alternatively if the velcro doesn’t have a adhesive side, sew it on with a needle and thread.

Step 7:

Drape the lycra over the plastic arch, and mark the place where the LED should protrude. Use your exacto knife to poke a hole into the fabric, and stick the LED through the hole. Continue to tightly wrap the fabric around the device until the ends meet at the back. Use hot glue to secure the ends together, trimming the excess fabric.

Step 8:

Glue the edges of the fabric to the side of the plastic casing, being cautious not to come into contact with the wires.

Step 9:

Trace the side of the plastic component onto the artboard, and cut it out. Wrap this piece with fabric and attach with hot glue. Trim the excess fabric before attaching this piece to the plastic tubing. Make a second one with the top cut off so you can charge your device. Be sure not to attach the first one to the side where the USB jack is at, as the extra room in the second one allows you to charge it.

Step 10:

Cut out the pieces from the art board as depicted in the picture. Glue the pieces as directed, and wrap them with electrical tape to ensure durability. These will act as the connector between the device and the belt strap.

Step 11:

Feed the belt strap through the connectors.

Step 12:

The device is now finished, and ready for wearing!

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    Cool. I could use one of these so that I am not constantly missing appointments.