Summary

pls excuse/ignore the spelling and random capitalization, lol.

This is a Original Design...

Using:

• 18650 Cell
• 2 Pole JST connector (While plug for power)
• 4-5 cm wide Elastic Strap (i actually went to a tailor near me for a somewhat harder .. "bunchup resistant" strap and that was a good idea... dont make the mistake and think soft is good xD)
• ESP8266 D1
• Adafruit BNO085 breakout Board
• common Ebay battery contacts spring and flat...
• thin wire... i used enameled coil wire (because its easy to work with, lightweight/small and simple)
• a length of simple two stranded isolated wire for power.
• a 4mm printer nozzel
• some hotglue

Optional:

• reverse protection Diode... (i recommend ones with low forward Voltage although even ones with 0.8V Drop do work) (it is theoretical Optimal but i wouldnt run without.... BNO085's are expensive. And at some point, you will put the battery in the wrong way and be kinda sad... ask me how i know.)
• Resistor around 100K for Battery Voltage (the ESP8266 dies at roughly 2.6-2.9 V so you wont destroy you battery while using the trackers either way)

This is the second revision of the Third Design for a Tracker that have build and used for roughly 500 hours in VRC At this point....

All started with an Idea:

• Keep it simple, Stupid... no switch, no powerbank module, no Lipo... just. put. in. battery.

That turned into:
"ohh i can just swap them when they get low... ppl be like: ' ohh, ima be on desktop for a bit... i need to charge my trackers...' - > laughs in slimevr"
turned into:
"ohh since and ESP8266 D1 and the BNO085 only take around 100 mA ... this thing runs for 20h ... with an expensive cell even 30h o.O"

Previous Designs had the Tracker and the battery as one unit but the inertia and weight made it wobble and move a lot so this is why the new Design is split into the Battery holder and the Tracker "Card". resulting into many benefits:

• Super flat design dosent get caught, has lots of surface on the body and dosent like to twist or move around.
• super light weight tracker make the Tracking look way "crisper". The low inertia really just makes it look smoother because its actually moving with the body and not on its own...
• it can just be opened and worked on or inspected but is being held closed while worn.

Surprisingly the battery although it looks bulky is really lay-on-able or sleep-on-able. And since they can be moved around independently they can just be put to places where they cant be felt...

for flashing i use the butterscotch flasher and just setup the Pins acordingly ... luckily except for the Voltage sense pin... every other pin from the ESP to the BNO can be setup as one likes...

i Provided Fusion Files, Step files and the STL's so is as everything else free for you to do what you want with.

i would like like some mention to the creator and just give the same access you had for everyone else as well.