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Pages and Files
Quick Start Guide
History of Major Design Decisions
Ongoing Validation Testing
Which Phones Can be Used and how? (coming soon)
Phone Testing Procedure (coming soon)
Obtaining Wockets Hardware
Option 1: Make Them Yourself (Detailed Info on Assembly) (Coming soon)
Option 2: Buy Them in Small Quantities (Coming soon)
Option 3: Collaborate with Wockets Team (use loaners) (Coming soon)
Testing and Calibrating Wockets
Calibrating a Wocket
Testing a Wocket (coming soon)
Google Code Site
(all software, including firmware)
HW Design History and Tech Specs
Wockets data formats (coming soon)
Wockets Software Architecture (coming soon)
Wockets Timestamp Correction (coming soon)
Wocket Enclosure and Band
Housing V3 Sealer Construction
Sensor Housing V4 concept and production
Bands and poach concept and production
Activity Recognition Software
Research Papers - Reading List
Wireless Sensor Kits
Other BT Sensors
Open Source Hardware
Open Source Tips
Physical Activity Conferences
Legacy Stuff (e.g., MITes)
MITes Design Info
Files for MIT/Stanford/UT/Northeastern Projects
Our goal is to make the Wockets enclosure waterproof.
One idea is to use two layers of protection:
Parylene conformal coating
Layer 2: Polyethylene housing
Waterproofing electronics is not difficult, but waterproofing electronics at low cost and thinly and in a way that can be done at low and high volume production is tricky.
We have tested the Parylene coating and it appears to work. Here is an image of a Wocket V2.1 transmitting while immersed in water.
We have also built a device to heat seal the sensor in a polyethylene housing. It creates a housing like the one shown here (we handle the seal around the microSD using polyethylene tape that adheres to the PCB, which the polyethylene outer film then adheres to (and pressure seals) during the sealing process.
This method meets our design criteria, but the polyethylene housing cannot withstand much abrasion, which can happen if the sensor is just placed in pockets with keys, a phone, etc. Nearly invisible holes can develop, and if the sensor is placed in a washing machine (our test case), water will seep in.
The method will be adequate for short term testing, but the sensors are not going to survive much abuse.
We are looking for alternative methods. We've thought about potting/encapsulating the sensor and battery (using custom molds that round edges) and using polyetheylene to encase and protect the wire and hold the sensor together, but we have concerns about thermal expansion and sutability of potting for production runs.
Ideas? (That don't substantially increase thickness or cost and provide a waterproof layer?)
Resources related to waterproof enclosure:
waterproof coating, such as
Liquid/spray-on sealant: Novec EGC-1700, Vappro 900
Example of waterproofing a USB flash drive
Example: Waterproofing a servo
Using something akin to this?
Acrylic finishes for artwork
Challenges with potting (
useful discussion thread
Source of encapsulants
help on how to format text
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