Why the first board is large.
The electrode connections, test points, battery measurement and other choices that made the board easier to test.
Design and test notes
How HydroGuard is taking shape.
Three notes on the first working board, why we made it large, and what we changed for the smaller second prototype.
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Testing the first prototype.
How we checked the measurement circuit on the bench and what happened when we tried it on a person.
What we changed for the second prototype.
A smaller controller, lower power use, motion sensing and a humidity sensor under the band.
Adapting the app to the second prototype.
The app now knows about the new board, and preparing it showed three things the firmware cannot report yet.