here are the circuit guts of the sleeve

closeup of the main circuit board “puck”, surrounded with silicone caulk

here is a detail of the 6 magnets used to have a waterproof connection to the circuit to charge and reprogram

here is a tweet from a SoHE social media guru @UWMadSoHE

1) Describe the operation of your final project. What does it do and how does it work?

My project is a waterproof, swimming arm sleeve that is worn as a motivational tool to  help facilitate aquatic workouts.  It functions by counting individual strokes, that accrue to light up six successive LEDs to indicate the user how long they have been working out.


2) Overall, what are your feelings about your project? Are you happy, content, frustrated, etc.?

I am overall happy.  I need a little bit of break from my project, which I think everyone experiences once finishing something big, but I’m sure in about 3 weeks I will be excited about it again, and I will actually try swimming with it.


3) What were the largest hurdles you encountered in your project and how did you overcome these obstacles?

My largest hurdle was organizing everything that needed to go into the armband.  This main hurdle was obtaining supplies online and waiting for them.  I was ordering fabric, magnets, LEDs, an accelerometer through three websites and then obtaining silicone caulk and wire in-store.  Organizing all of these components was a struggle for me and it did drag my schedule behind, but it overall worked out.


4) How well did your project meet your original project description and goals?

I think my final product  95% matched what I was intending to make.  The main component that went into this is my waterproofing design and Nathan’s idea of splitting the USB and having magnet ports.  The 5% off was I think the use of a switch to turn the battery off and allow the entire circuit to reset.  This was a last-minute design decision that I had neglected, but luckily Kevin helped me through it.


5) If you had more time, what would you do next on your project?

If i had more time, I would make the overall package more streamlined in two separate areas of the circuit design and then the fabric sleeve itself.  I would redesign the circuit to include less wire, that is also more flexible to make the entire arm sleeve less bulky.  I would also redesign the arm sleeve to accept the circuit better and possible include a clear fabric to see the circuit more clearly.  On a second chance, I would also put the 6 magnet USB ports to the outside as a visual element to show off the tech.


late by a day, i know. but i got a lot done tonight to share!

here is a nice tatt to visualize how the coordinates are manifested on the athlete’s arm

here is a very nice photo of a magnet successfully nested in the knit fabric with silicone caulk

here is the prototype sleeve for sizing purposes

here is a movie prop from Elysium.  That is Matt Damon’s arm and he is modeling and testing the readings of the accelerometer.


here is a circuit completed with the use of the magnet as evidenced by the lit LED

What did you do this week?

I did a lot this week relative to past weeks.  I started soldering my circuit, which was really fun.  I also patterned and constructed the fabric sleeve “muslin”.  With the completed circuit, I tested LEDs and took accelerometer readings based on swimming movements.  On Sunday during my lifeguard shift, I took at swim to figure out rough stroke counts per pool length.  I really did a lot of little chores that included a lot of little tests.

Describe the problems you encountered.

The hardest thing this week was using the cold heat soldering system.  Tonight, I accidentally broke the tip so that was not good.

another thing that i have a problem with is that i am making my wires too long and they are going to be taking up a lot of space.

also, neodymium magnets lose magnetic force when heated so i kind of destroyed a lot of their magnetic hold when using the cold heat soldering gun…..

Describe the successes you had.

I won’t get to all of them, but I found that the magnets conduct electricity.  I found my circuit works in that the LEDs function and accelerometer takes accurate readings. I found that the silicone caulk fuses well to both the knit and the magnet.  I tested an iron-on tape that should help my magnet openings.

Are you on schedule?

I will finish by Friday.

What do you plan to do this week?

Finish strong and program a lot.

This week’s progress

  • What did you do this week? [Include image(s)]
Here is the current test of an LED covered in silicone caulk.  It functioned and was very bright still.
Here are tests of pink and blue LEDS that I received.  I am very pleased with their brightness and color.  I have decided that pink denotes the lowest workout(warm), blue is a medium workout(water, but getting “colder”), and white is the hardest light to attain(rock hard body like ice, also “icey”).
Here is my white knit spandex fabric soaked with water, showing how the LED shows through and I am very pleased with the results.
  • Describe the problems you encountered
The main problem was being lazy from Thanksgiving and not having as much time.  The bulk of this week’s work was during the Tuesday class.
  • Describe the successes you had
Successes include having successful tests of LEDs and confirming of the use of the silicone caulk that I have been using.  I believe it will waterproof my circuit very well.
  • Are you on schedule?
I am not on schedule to where I comfortable.  Of all my final projects, this one stresses me out the most, but this next week IS going to change that.
  • What do you plan to do next week?

Main thing to get done next week is coding.  Once coding is done, this project is easy for me to complete on my own.


  • What did you do this week?
This week I showed up late to class to obtain LEDs from a Fedex location.  Once I got to class, I put another layer of silicone caulk over a dried layer of caulk and I also tested super glue on the dried caulk.  I also made a little waterproof test caulk with a little litmus strip that will show if/when wet:
I checked on my slow-to-ship magnets and they’re making their way here…
  • Describe the problems you encountered
I needlessly cut a USB cord in half so that was a problem.
  • Describe the successes you had
I had a lot of successes this week.
I had a really great one-on-one talk with Kevin.
I obtained very cheaply some wire lead things from Alper and Nathan that really helped my circuit out and simplified it.
I started talking readings off my accelerometer which was very encouraging.
  • Are you on schedule?
I’m on a whole new schedule and I feel great.
  • What do you plan to do next week?

Tuesday is going to be great.  I plan on testing both the dried silicone tests.  I also plan integrating my 6 LEDs in my test circuit.  Hopefully I can work through more accelerometer programming as well.


What did you do this week? [Include image(s)]
This week I stayed home sick and spent the big dollars on some new materials.
I ordered the magnets I am going to try out. They are little half-inch magnetic disks.

Next I ordered fabric:

Describe the problems you encountered

My main problem was missing class.  Another problem is shipping cost and it is too expensive.
Describe the successes you had

This complete post is about the biggest success this week.
Are you on schedule?

What do you plan to do next week?

I plan to go to class and be healthy.  I plan to have a nice little sit-down date with my accelerometer and really get personal.

week 2

this week i awaited the arrival of materials mostly

using the multimeter and pool sample water, it was determined that my current design will not short

I have selected a fabric, but have not yet ordered it

kevin directed me to think about programming even if i didn’t have my accelerometer, and so i problem-solved the coding a little bit

main problem is not having the materials yet and the main success was finding out that water doesn’t conduct the way originally thought over a distance so that was a step in the right direction.

i am behind

next week i plan to start using my accelerometer to collect data that i can really hash out the coding with

Week 1 progress

This week was a struggle but I got some stuff done.

I have ordered my accelerometer and colored LEDs

i have extensively narrowed fabric choices down from swatches i have

Nathan and Kevin have helped me make my project more ambitious with the use of 4 or 6 magnet terminals as a way to effectively “waterproof” my unit, but allow it to communicate and charge with the outside world.

Most importantly, today I had a nice swim for research and collected a sample of genuine SERF pool water.

Goal for this next week is to post the weekly update on time.


hydro arm shiver


This forearm band is to measure physical activity while swimming laps.  LEDs are turned on and accumulated as the workout goes longer.


The Nike Fuelband is the main inspiration for the project, except since that product is not waterproof, that is where this project takes over.

Project Materials and Cost

fabric – $15

accelerometer – $15

lilypad – $60

waterproofing resin – $20

waterproof USB – $15


  • acquire materials
  • convert Nike Fuel points to water activity
  • test waterproofing methods for circuitry
  • code with accelerometer
  • test motion capture with swimming motions
  • construct arm band
  • prepare materials, like a fish tank, for presentation

Backup Plan

Put entire electronic housing in waterproof pouch if resin system fails.