What are wearables? Wearables are miniature devices processed in for example earphones, clothing, insoles, glasses, watches, etc. Thus generally they should be small and lightweight, but should also have a low power consumption. Power management strategies like sleep mode and auto shutdown should be considered to minimize power usage. Of course a wearable should also have connectivity using for example Cable, bluetooth, WIFI, cellular, etc. depending on the use case. External influences should not be ignored, because these can potentially break the usefulness of your wearables (water proof, drop proof, sweat proof).
Gerrit Grunwald devised his own (do it yourself) wearable devices for the jRunner project. In this project he wanted to have heart rate monitoring, track the runner using GPS and be able to give instructions to the runner with text messages (using Text To Speech).
Furthermore the information should be published such that a desktop app can be created as well (see below image)
He iteratively tried to find the right hardware components taking size and battery usage into account. Especially minimal battery usage is difficult to achieve in combination with connectivity. Eventually he used his smartphone as connectivity device that connects with the Raspberry Pi via low energy blue tooth (see below image for an overview).
For publishing data from a wearable devise, the MQTT protocol is most suited, because it is lightweight and basically is a publish-subscribe protocol. By combining all these things we was able to realize all the things he wanted and is still trying to optimize his setup in size (Below is the current hardware that he uses). Next iteration he will try out a much flatter chip than that he currently uses.
Angela Caicedo, the second speaker had a different kind of approach in wearables. She integrated circuits into a vest like leds and buttons (see below images).
She encountered more problems in the area of processing conductible wire into clothes and getting feedback upon clicking buttons. To resolve the feedback problem she introduced vibrations upon button press and feedback through self made glasses (with 320 x 200 resolution).
