Final Report Links

Final Report PDF:
https://drive.google.com/file/d/0B6ckAjfSqbv4aVVjRjlkcUQ4VGc/view?usp=sharing

Project Video:

https://www.youtube.com/watch?v=HpzAGq8CUxU

Code:

https://github.com/ese350/2015-ESE350-SmartPaddles

Mbed Directory:

https://developer.mbed.org/compiler/#nav:/acc_testing1

Final Demo Slides:

https://docs.google.com/presentation/d/1s2HQ3QacbrwG_8Cs8QS-BYcYb-hVU3FbtaO7cTsOpdM/edit?usp=sharing

First World Problems

We redesigned our shield and paddle to add an extra inch of length for the extra wires. We decided this would make our assembly much faster and easier. Our waterproof switches are soldered and ready to go and our code is restructured for switches rather than buttons now. Our new model also has an on/off switch so we don't suck as much power out of our battery. Fittingly, the line of holes along the side of the shield look like little bubbles. We'll just pretend that was an intentional design choice.

Unfortunately, we ran into a long period of unexpected Makerbot issues and our prints kept warping around the edges. Keeping everything in perspective, if your biggest problem is that your 3d printers aren't working properly, you're doing alright in life.

We think it will still work in the pool if we seal the connection with enough putty. We're about to waterproof so we can hopefully water test everything tonight and tomorrow. We have a lot we still want/need to accomplish before the final demo on Friday, but we're optimistic. Wish us luck!

Baseline Demo Recap

Demoed our baseline dry prototype today and we only had a few small hiccups. Our current shield configuration is very hard to connect to the external buttons and LEDs because there isn't much space in the shield for extra wires and the short wires from the lid essentially require us to connect everything to the mbed upside down. Also, because our paddle pulls so much current with the bluetooth and SD card reader, our LiPo batteries kept dying in relatively short amounts of time. We think they weren't fully charged before the demo though. They have a current rating of 1000mAh so we should have about 5 hours of charge for fully charged LiPos.

Our reach goals for next Wednesday/Thursday:

• Use machine learning and data analysis tools to identify catch, pull, and recovery within the stroke - information that could be used for swimmers to make better sense of their individual acceleration curves.
• Refine our vibration actuation so that the feedback is meaningful for the swimmer.
• Incorporate waterproof pressure sensor data.

Super reach goal:

• Inductive (wireless) charging!

Here we go!

Final push before demo day! We finally got bluetooth to work with an Adafruit Bluetooth Mate Gold chip! We reprinted a nice shield for our dry prototype demo tomorrow and secured our LEDs and push buttons into it. Our vibration actuation is working better than ever, and with a little courage and force, everything fits in our shield with a nice press fit.

Take a look at our videos!

Water testing:

https://drive.google.com/file/d/0BzbUOrDmIYKwZ0oyMXF1Y2FuTTA/view?usp=sharing

Pre-demo demo:

https://drive.google.com/file/d/0B6ckAjfSqbv4YjVrTVhGdXhYMFk/view?usp=sharing

We also attended a data analysis workshop and are planning to use MATLAB and SVL analysis on our water data for next week.

Good vibes

Used heat shrink to prepare our vibration motor today. We're actuating nicely, but Laura is going to work on refining the algorithm so our actuation is even better on demo day. After letting our LiPo's dry out overnight, they are working as good as ever today! We decided we're going to wrap and seal them in balloons in the future to prevent them from ever getting wet again. That was way too close a call. We removed the right most power rail from our breadboard to give us more space to work with onboard. We're still waiting on our pressure sensor breakout, bluetooth chip, and waterproof switches. Hopefully all that stuff should come in tomorrow.

We need to 3d print at least one more shield before demo day this Friday. With only one working Makerbot in Detkin and a limited number working in the MEAM lab, there is naturally a very long queue to print this time of year. I snatched an SD card and intend to be the very first person in line when Parth comes in at 9:30 tomorrow. We're hoping to watertest again tomorrow, but we're not taking any chances this time. We're sacrificing all style points in favor of safety by wrapping the entire waterproof shield with 5-6 layers of saran wrap, ziploc bags, and duct tape. At this point, good water testing data is far more important to us than having a finished looking product.

Tonight, I need to re-CorrosionX all the tech for tomorrow. Tomorrow we're preparing our final demo shield with working LEDs and buttons, improving our actuation algorithm, presenting some data processing, collecting some more water data, preparing our presentation/video, and potentially interfacing the bluetooth if the chip has arrived. We have our work cut out for us, but with CorrosionX and elbow grease on our side, we're ready for the adrenaline to kick in as we cross the finish line.

CLOSED LOOP

HI!

Late at night we sit in Detkin lab, Team MetaKnight sat wondering why we did not graduate high school and then pursue successful rapping careers. While we were not just signed by Jay-Z, WE DONE DID FINALLY CLOSED THE LOOP.

Rewind 26 hours, we spend a wonderfully toxic night in Rodin waterproofing our magical box. The fumes were flowing from slimy, slimy Corrosion-X. To add to the stench, we diligently squeezing and smoothed all the little cracks in the shield with aquarium sealant after sneaking suspicions that the cause for the water attack early in the day was due to the 3D printer's approach to creating levels in the structure.

Boy oh boy, buttons were driving us mad. We tried many make-shift approaches to attempting to keep the buttons in place under the patch of swim cap material. Try as we did with aquarium sealant, q-tips, chop-sticks, and now chemically infused fingers, the little buttons that could, couldn't.

Recognizing the need for water data the next morning, we decided to control the device without the buttons and move forward for this iteration.

But before we threw our electroniques into the pool, of course we needed to put our second round of waterproofing to the test. Catherine strapped up with an empty smart paddle and made like a fish. After flipping her fins, we anxiously dried the outside of the paddle to see the results..... Only a few drops of water made their way into the paddle. This made us very excited as this was a major improvement from the day before.

Riding the high of our dry, we prayed to the Corrosion-X gods, put our board in a plastic bag as a final barrier for those few drops of water, and screwed the lid on tight.

Well, it could have been worse. After Catherine swam 4 good technique laps followed by 4 poor technique laps, we opened to paddle. This time, some H20 homies seemed to throw a party in the plastic bag. The mbed light was off, and we weren't invited to the party, so we were now upset for two reasons.

Mild panic ensued as we thought we ruined our parts. Catherine and Aadu did the magic testing, and it turns out the batteries were playing a practical joke on team MetaKnight. One of the batteries ran out of power. Our entire circuit survived the rain storm - Thank you Corrosion-X! However, sadly, the loss of power mean that we did not get to save the swim test data! :(

We took this moment to learn where we could improve our waterproofing. We emptied the shield and lowered the apparatus into the water. We watched bubbles leak from the seam on the shield, the gap between the shield and the base, and near the screws. NOTED.

6 Insomnia cookies and 2 milk jugs were all it took to get MetaKnights spirits back in shape as we rallied back to Detkin Lab. We hit a few bumps while some leads fell off, but we managed to wire up the vibrators to actuate with our code! We implemented an algorithm that computes and analyzes the combined acceleration to keep track of the strokes. When the swimmer slows down too much, the paddle will turn on a light for a second to remind the swimmer to speeeeed up!!! Its super exciting and fun to play with. Next step is to get another vibrator to attach on up.

Rolling with the Punches

The theme of this post is developing a Plan B when Plan A fails. We've hit a lot of walls in the past few days but we are determined to push through and create an awesome project whatever it takes. Over the weekend, we realized the hard way that soldering our components onto a solderable breadboard is simply not going to work. We burned out an mbed, one of our microSD card readers, and an accelerometer (Yes Aadu, I will unsolder the mbed). Fortunately, we had backup for all of the critical components. We realized that we're going to have to make do with the non-solderable breadboard. Space is becoming a point of concern on board and will definitely be a challenge when it comes time to add a vibrator, pressure sensor, and bluetooth chip.

Shield Base with breadboard

We adhered our silicon button lining and LEDs to the front panel with 100% silicon aquarium sealant and it dried nicely. Unfortunately, one of the LED leads snapped off this morning so we will need to re-attach one of the LEDs.

Inside of front panel

This afternoon, we did our first wet run without any of the circuitry inside to see how watertight the paddle was. We sealed the snap-fit cavity with waterproof putty and screwed the shield together very tightly. Unfortunately, as you can see below, the piece of paper we had inside got very wet. We identified the problem area on the shield lid and tonight we are reinforcing all the of the weak seams with aquarium sealant and we will try again at the pool tomorrow. Makerbots are not perfect and neither are we, but we're just going to have to roll with the punches. In the very worst case scenario, the shield will not be waterproof and we will have to demo a not-quite-water-safe product. :(

First wet run - Thank you for filming, Coach Dan!

First wet run failure

We've been doing a lot of land work to analyze collected acceleration curves. We have identified a common bad swimming habit that we can quantify and use to "close the loop" with an on-paddle vibration motor that will indicate to the athlete when his or her fingertips are not angled properly.

We are still waiting for our bluetooth chip and pressure sensor breakout to arrive. We will have to figure out the on-board space issue very soon. Final demo day is in four days and we are in panic mode. After 6-8 hours of work every day on this for the past four weeks, it would be a shame to see everything go down in flames at the last minute.