LEARNING
TO MAKE


Week 17: Applications & Implications of Final Project

Final Sense: A Biosignal VR Bracelet


What will it do?

"Final Sense" consists of a bracelet that includes a "galvanic skin sensor" or EDA that collects electrodermal activity. The data generated through the measurement will follow two outputs: range of 15 LEDs on the bracelet will turn on according to the intensity of the biosignal; additionally the data will be captured in a datasheet to be rendered useful for further analysis.


Who's done what beforehand?

Academic Research
* MIT Media Lab Project "the galvactivator"and FAQ.
* Cornell University Course on EDA Sensorto meassure mental states
* Research article on electrodermal activity
* Wiki of the "Biosensor Array Project" on Galvanic Skin Response


Art & Making
* Inspiring project: "Stress" Makes Art - A Galvanic Skin Response and Visual Generation
* Galvanic Skin Response prject * "truth sensor" prototyping
* EDA goes wearable
* blog
* Blanca Duarte (Fab Academy 2012): bracelet cast in silicon
* hacker projecthere and here and here


Commercial
* Commercial emotional sensor device here and here. The latter has a support page for signal processing and data analysis.
* DIY & semi-commercial biosignal hardware kit from bitalino
* Pumping Station: here and here


What materials and components will be required? Where will they come from?

* PCB: self designed
* Components: Fab Lab BCN supply, eg DigiKeys
ATTIny 85 | AVRISP (2x3) | FTDI header | R1 10k | R2 499 Ohm | 5V Regulator | Cap 1uf | Cap 100uf | 15 NeoPixel LEDs from adafruit | Battery Holder (for 2 coin batterys) | 2 coin batteries a 3 V |
* EDA Sensor: two copper plates, linked to board with jumper cables
* For bracelet/wearable: silicon Form Sil 25 Pro from Form X (C/ Roc Boronat 39; 08005 BCN) for prototype and leather from corner store (in C/Hospital; 08001 BCN) as well as press buttons for final wearable


How much will it cost?

* Leather & press buttons (not all used): 17 Euro
* Components & cupper board: around 2 Euro
* 3D printing fillament: xx

--> TOTAL: 10 - 12 Euro material costs; excluding machine time & working hours ; )


What parts and systems will be made?

* Everything, except the materials themselves are self made.



What processes will be used?

* Software: Rhino, Eagle, Arduino & processing for coding and data visualisation
* Machines: Rolland SRM-20 Milling; Multicam Lasercutting; Formbytes 3D printer;


What tasks need to be completed?

Design of the bracelet:
* buy leather
* make paper prototype
* take meassurments
* design two leather leyers in Rhino
* lasercut leather
* design plexiglass base for board and for the two sensor cupper plates in Rhino
* laser cut the three plexiglass pieces
* mill two sensor cupper plates
* design mold to cast the protection shield in silicon
* mill the foam mold and wax it
* cast it



Hardware & Code:
* Use hello world board as prototype to develop and test code: changing LED according to sensor input; inlcude smooth signal code; ATTiny 84 reaches limit, the script is too large for it, so new plan:
* final board design with ATTiny 85 in Eagle
* schemantic modified in Gimp * mill board in SMR-20 * Solder the new board, including new LEDs: NeoPixel from adafruit
* program board
* troubleshooting period



Presentation
* Video Making
* Webpage updating


What questions need to be answered?

* Which microchip to use - Attiny 84 is not available, ATMega32 is over-the-top, ATtiny 85 generated mayn problems in the class. Anyway, ATtiny 85 serves my purpose and is available, so that´s the one.
* Usefulness of data: how acurate and meaningful is the actual data collected? I need to try to find out.
* Practicality of device: The bracelet has a battery for on-the-go and fun & play usage. However, for actual data gathering during the Machine To Be Another experience, the device needs to be plugged into the computer - the AtTiny 85 cannot handle a prolonged accumulation & storage of data. So, after the fab academy prototype, I need another microchip to "unplug" users and maintain freedom of movement without cable constraints.


What is the schedule?

Everything now and immeditaly. I have missed 6 weeks of FabAcademy I use my final project prototyping to fullfill the asigments and learn about my actual doings. The knowledge provided in Fab Academy was a black box to me, so I could really plan my final project at the beginning of the course - which would however been wonderful to do. Now, being in the final project rushing madness, I see that I am actually following a spiral making process, moving back and forth between electronics, object design, prototyping and testing, taking it from level to level. In order to have done this in a planned and scheduled manner, I would have needed to know before the course actually started what I learned only during Fab Academy. Chicken Egg problematic, but it´s great fun.


How will it be evaluated? How do you tell if you suceed or fail?

I am happy if the code and electronics are working - LEDs blink according to sensor intensity - and the various materials are securely integrated, generating a stable and aesthetcially pleasing bracelet. However, my key goal is to actually use the bracelet during The Machine VR experience, to collect meaningful data and to apply the bracelet as a tool of interaction: to talk with users about their understanding of contemporary technology in society. This way, not only BeAnotherLab´s work but also my PhD research can benefit from a creative methodology.


Which skills of digital fabrication are covered?

* computer controlled design
* 3D printing
* laser cutting
* embedded programming
* electronics production & design