SafeBand – 07/12

  • What did you do this week?

We worked on the Bluetooth connection and on the send e-mail functionality from the app.

The Bluetooth is working fine and the app is now able to send e-mails.

  • Describe the problems you encountered

We had problems to send e-mail due the filter encountered in the major e-mail web services companies such as Google and Microsoft Office. To solve this problem we had to use a external framework called MailGun (

  • Describe the successes you had

Now we’re able to send email through the app and the Bluetooth connection looks like to be working fine.

  • Are you on schedule?

We’re a little late, but we will be able to finish everything.

  • What do you plan to do next week?

We will make the necessary connections between smartphone and the device and sew everything.


This week we further developed the muslin (rough draft of the jacket). It’s pretty much ready for testing with the electronics which we are planning to do tomorrow night. We have the accelerometer hooked up to the Arduino and providing somewhat consistent results. We are going to continue to work with the accelerometer data to get the functionality we need. Some challenges we ran into included redeveloping the original pattern so that the electronic elements will fit in. For this coming week we’re planning on testing electronics, getting the lights hooked up, finishing the jacket, and making our poster.


Gaming Gloves 12/7

This week we finished the finger’s cover with the pressure sensors added to it. As you can see in the picture below, we made a two layer’s cover to hide the sensors. We had already tested and all of the sensors are working perfectly by sending a response whenever it suffer any pressure. The arduino code is already done and we plan to finish the software by Wednesday. Besides the software all we have to do is just finish to plug all components of the glove in the actual prototype what should take us less than a day.


12/7 TypeSafe

This week’s activities:

– Got a nice sweatband and used it to build the first, rough prototype of my device. This involved quite a  bit of stitching, soldering, connecting things with wires, and taping them to other things. Here is what the prototype looks like:


– I’ve also written a good chunk of the Arduino code, though the meat – activity and posture inference – is still missing.

Problems encountered:

– My first attempt at prototype didn’t work at all. IMU was unreliable, due to wiring issues, and I also had a few shorts due to stitching issues (stitching  on this wristband is not as easy as on a rectangular piece of fabric).


– All of the hardware problems that plagued me before seem to have been resolved.

I’m behind my original schedule, but reasonably confident that I’ll have a working prototype in time for the showcase. It just won’t be as full-featured or as pretty as what I originally envisioned.

Plan for next week:

– Implement the activity and posture inference in software.

– Demonstrate a working prototype of the device.

– Make a poster.


12/7 : Lights-up Dress Weekly Post

This week I was working on the sewing the shift regiesters and leds to my dress. I will use two pattern in the picture below to sew the leds and  I will use two blinking patterns that I found last week and speed of them. This week I did not had problems to solve these patterns without that I couldn’t control sewing speed  because the dress is so long  and the leds are very small. I think that the size of leds are the problems because they are really small so it will not be that recognizable when I have only  some of leds. I think I am little bit behind on my sechedule because I think dealing with the shift register and accelerometer will take more time than I thought and I have no idea how to work throgh them by myself. My plan for next week is that I want to start programming the accelerometer and accelerometer with shift register together.



사진 1 (1)사진 2 (1)

End of Semester Considerations

As the end of the semester is rapidly approaching, I thought I would list some thoughts and considerations.

Friday’s event is open to the public
I am guessing we will have between 50-100 people, but the event the last week drew 200+.  In this regard, having a good and functional project is important not only for your grade, but also for your own esteem.

Better late than never
Any work that has not been submitted gets a zero.  Late work however, can get up to 50%.  In this regard, you may want to check back through your postings, assignments, etc and make sure you have something there.  You may also want to email me to let me know if you posted something late so that I don’t miss it.

Projects and posters can not be turned in late
The event happens at 5pm on the 12th.  There is no ability to turn these items in late so make sure they are done on time.

Make sure you are following directions
The project posting guidelines can be found here

Make sure your posts include all of the items.  If they don’t you will lose credit.

Make sure your posts are labelled correctly
If the category for your posts are set up correctly, people following your project will have a tough time.  Be sure all of your posts have the correct label

12/7/2014 TEB Update

As the deadline approaches, the project is getting more and more stressful which was expected.  With that being said, it was quite the relief to test the board and see that there were no problems with the board that would require me to order another batch.  I am still on schedule and should be able to finish the complete prototype by this upcoming Friday.

  • What did you do this week?

This week, I continued to test the  functionality of the board with the code that I wrote.  Of course, testing comes with a lot of debugging so a good portion of my time was spent on solving problems involving my code and just ironing out the kinks of the program.

I also spent time over the weekend fabricating the mounts for attaching the watch band to the heatsink.  I was very pleased with the results.


  • Describe the problems you encountered

I encountered a number of problems this week, but luckily I was able to solve them quickly.

1) When I first powered my board, I noticed ‘magic smoke’ and disconnected the power supply.  I then realized that I had soldered my diode backwards, which had fried my boost converter chip

2) I noticed when testing the populated board with my multimeter that there was a short somewhere.  However, when I tested the unpopulated board, there was no short. I first thought that I may have accidentally bridged some pads during the surface mount soldering operation.  I inspected every component and ruled that cause out. I further deduced that this short was a result of soldering my diode backwards. It turns out there was an internal short within the boost converter chip so I removed the component and there was no short!

3) I forgot to place a power switch on the board when designing the PCB. To solve this, I had to solder the header sockets on the board and now to turn on the board, you just insert the microcontroller and that initializes the program.  When it is removed the board, no current is drawn.   However, because I had to solder these headers, that adds 1/4″ to the height of the unit

4) When testing my LEDs, they were not illuminating.  I took another look at the schematic and realized I mixed up the anode and cathode.  To solve this problem, I cut the common anode trace to negative and placed a jumper to the positive line and then I had to account for this in my code by pulling the pin LOW instead of HIGH to turn on the LED.

5) Next problem I had was with my code.  When testing the if the LEDs responded to the push buttons, I noticed only one button was working. Well, this turned out to be a bracketing issue.

6) The last problem was also with my code.  Finding an alternative day of performing a digitalWrite in the loop without using the ‘delay’ function.  If I used ‘delay’, the program ran very slow and often didn’t function. To solve this, I made use of the millis() function. You can see the code in the following link

  • Are you on schedule?

Yes I am! I should be able to finish the complete prototype by Friday

  • Describe the successes you had

Like I said above, I was very pleased to find that there were no problems with my board that would require me to print another board.

I also was able to fabricate the physical device without any issues.

And also, after many hours of debugging, I wrote a program that works very well.

  • What do you plan to do next week?

Next week, I plan to wrap up the prototype and test if it actually gives you the perception of your body heating or cooling down. i will have to test many pulse frequencies to find the optimal one that is most effective.

Testing thermoelectric generator using photoelectric cells in series


Complete PCB for prototype 1