Update 2011: New schematic with clearer instructions.
Im in the middle of working on a product for class which explores two fields: 1. The use of light for sleep induction similar to sound and motion. 2. Games for remote intimacy. Sometime later I will show designs and describe the product in more detail. Here and now I want to describe some of the technology im exploring to be used in the product. I believe that good industrial design requires exploring various materials before finding the right application. There are 3 distinct work modules for this project that each have different possible solutions.
Sensor: Biometric interface to monitor heart rate
Connectivity: Wireless communication
Feedback: Illuminated fabric
1. Biometric interface to monitor heart rate
I’ve had experience with pulling apart an ECG for reuse in a similar project. The work on this project cannot be easily replicated for future projects since it depends on the ECG found and requires a great deal of reverse engineering. Hence I wanted to build from schematic this time around.
1.0 schematic z
src probably the clearest description and instructions yet.
1.1 ECG schematic a
Using an ECG requires 3 points of contact on the users body. The previous project i worked on pulled this off using just the two hands. This might cause problems for my use. The AD620 amp datasheet provides a basic schematic:
1.2 ECG schematic b
Wright State University class and lab notes for and ECG, starting with the basics, explaining the basics of amplification, filter and the full ECG schematic also based on the AD620: Lab 1 2 3 4
1.3 IR pulse monitor a
I forget where I found this schematic. There was no documentation so I would like to find another reference somewhere:
1.4 IR pulse monitor b
Full schematic and firmware for MCU provided. I cant remember from where and cannot upload the firmware files here so, if you need them, email me. I will probably swap the PIC MCU for an Atmel and port the firmware.
1.5 Piezoelectric film pulse monitor
One is described here includes filter and amplification schematics, gerber files and firmware. My preference is to avoid this method as it requires firm contact with a vein in the wrist or neck.
2. Wireless communications The prototype will based on Arduino and I found references for the following methods:
2.1 Zbee wireless modules
These modules do not provide a TCP stack but can be used to communicate to each other. This is fine for exhibition and prototyping but would need to be replaced or a TCP stack would need to be built on top of. They are discussed extensively in relation to the arduino. References: 1, 2
At 434 or 314 Mhz.
References: KLP Walktrhough from Sparkfun, Arduino Thread 1 2 3
2.3 Bluetooth with BlueSMiRF
These modules come in several packages. Ive back ordered the BlueSMiRF2 DIP. There are various tutorials and projects hooking these up with Arduino: 1, 2, teamawear project(see other blog posts in his project for additional details)
2.4 Bluetooth using ArduinoBT
There are discussions showing how to using one ArduinoBT bluetooth board to communicate to another (here and here). This would be a nice option for prototyping a bluetooth solution but will make swapping either the bluetooth or arduino modules for something cheaper or with a smaller footprint more difficult.
3. Illuminated fabric
The Electroluminescence Wire I’ve found for sale online is a bit on the neon/indigo side. I’d like to find something softer. Perhaps diffusion will suffice. I also need to find a place that I can purchase either designs (factory cut foil) or foil which i can cut at home. The Fiber Optic wire lighting solutions I’ve seen also appear either neon, not well documented, or just not readily available. I havent given up on either of these options, but I’m certain I can find or create a better solution.
Design inSight smart materials page (see “Light emitting materials”)
3.1 Electroluminescence wire:
Coolight (EL per foot. US. Referenced in the Make tutorial)
EL Wire (around per foot. in the US)
Livewire ( for 10″ but comes with driver, US)
Instructable for soldering EL wire
3.2 Electroluminesence Foil:
E-Light (the film can be ordered directly at for 9^2inch, or as a kit that includes a power inverter for The inverter doesnt support variable brightness. kit at 36^2 does)
TCMLight (in .de., crazy expensive)
Electroluminescence Inc (US, for A4. Inverter costs )
Allelectronics.com has Strips around 3×5″ for as well as others
There are two projects which detail their experiances with EL here and here.
1.4 Other lighted fabric projects or materials:
Loop.PH EL Pillow (note for sale)
Lumalive (luminous cloth from Philips, cant find dealer)
Dianalindesign LED based pillow ()
Hexgram shirt using EL foil (not for sale)
LED Dress (note for sale)
LED Tanktop (by Leah Buechley, Lilypad maker. Also see code and samples in Craft magazine)
LED bracelet diy tutorial (using Velcro strap as switch)
Concept bag (using EL strips, concept detail)
Interactive Pillow (using EL wire, concept detail)