Hi everyone,
I've a concern I hope you can help me with.
We're building an Arduino LilyPad project (fitness tracker) that consists of a LilyPad Arduino 328 Main Board, a LilyPad Accelerometer - ADXL335, five LilyPad LEDs, a LiPower and a 150mAh battery for it. The components are sewed together on a sleeve using Adafruit conductive thread.
While testing it, we've filled the sleeve with paper napkins so the thread from the up side (connecting the LilyPad, accelerometer and LEDs) doesn't come into contact with the thread on the bottom side (LiPower and battery). Probably a bad idea as immediately after powering the project up, we got smoke. We stopped. On a napkin there was a small hole thread had burnt through.
So, while it was a bad idea to use napkins, this brings up the concern of how much heat this thing can generate. I don't know if it is safe using it and what steps we should take to prevent the thread from touching the person wearing the device. Is it possible the device can burn through the fabric of the sleeve? I believe we've connected everything correctly as the device works as intended, but I'll attach our design to the post if you can spot something wrong (just ignore the capacitor, it's been moved to the FTDI breakout).
I didn't see any special precautions taken in any of the LilyPad tutorials so I'm concerned the mistake is at our side.
Has anyone any suggestions on what we could've done wrong or is it expected for such a setup to generate this amount of heat?
