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Some doubts: Lilypad Arduino, Accelerometers and E-textiles Answered

Hello all!

First of all, I'm a brazilian undergraduate Design student, and I'm very new at developing electronic projects (specially with e-textiles). I'm currently working on a malleable hand-held interface for my graduation project, and have been posting its development at this website: http://theinstrumentproject.tumblr.com/

Well, I've come up with the attached simplified schematics (just to communicate my needs and current intentions), and some questions raised from it:

About Arduino and the schematic:

- Will the raw data of the whole schematic (5 accelerometers to lilypad to bluetooth) be fast enough generated? - a frequency of 10 "readings" per second should be enough for what I intend to do with them. *

- How much power will the schematic consume? Are three 20mm coin cell batteries going to do the job? In how much time would they be drown out? *

About soft circuits and e-textiles:

- What is best to transport data and power through this interface: conductive fabric, conductive thread or even a really thin wire? - It is important that it could be folded, twisted and very resistant through time.

- Could you indicate any kind of textile more suitable for this application? - It should be just a little stretchy, and very resistant.

- Any ideas of how should I protect the components from damage by rough hand manipulation?

- Any advice about sewing the whole application?

(*) The main components:
- Arduino Main Board: http://www.sparkfun.com/products/9266
- Lilypad Accelerometer ADXL335: http://www.sparkfun.com/products/9267
- Bluetooth Mate Silver: http://www.sparkfun.com/products/10393

Hope someone here can bring me some light to these problems, but any kind of help, opinion or critic is welcome!



Depends a lot on your exact circuit.


You could run 5 of these, in normal mode, with 1.25mA. You could get clever, and shut them down periodically, to save power.


Wow, this accelerometer sure looks promising. I'm wondering if they come with breakout boards?

I just realized I've not posted the exact components I was planning of using - I'm updating the post and adding this.

I was actually thinking of using SparkFun's Lilypad Accelerometers. Here is the data sheet: http://www.sparkfun.com/datasheets/DevTools/LilyPad/ADXL335.pdf

But as long as the LIS302DLH can be sewable, I don't see why not give it a try (as it looks to have more features and such).

Do I assume you'll want these things to be as thin and low-profile as possible too ?


I don't think you can beat these for tiny-ness. Look for some "flexible PCB" material - you can spot it on Ebay occasionally. Its often used for making circuits that fit in very tight spaces, like cameras.