While I was about to throw my empty bottle of vitamins. I notice that something is still rattling inside, I looked into it and saw that there is this small cylindrical container, inside is some kind of silica sand which I think used as moisture absorbent. At that time actually I was planning to build a signal light for my bike, so it then gave me an idea, why not make a LED light diffuser out of this and see if I can use it as signal light for my bike?
I then looked into my electronic stash to see what I can use to make this LED diffuser. Then I came across to this broken step tracker (the name is "actxa stride") which I tried to fix but no luck. Inside this tracker is a very tiny 1s 60mAh lipo. So I took off the battery and see if I can be able to fit into the silica container, and it actually does. After that I gather couple more things:
Step 1: Gathering Materials
LEDs (blue, white, red)
3 way switch
I think I got these switch, socket and charging cable from one of my broken 1:36 scale rc toys.
Step 2: Gathering Materials
Step 3: Solder the LED to the Switch and Charging Socket
Don't be confused with the red LED. Actually at first I want to put red and blue but when I tested it seems that the red is not that bright compare to the blue, so I put white LED instead. Another reason for this is that white led can handle higher voltage than the red, that is why I did not put resistor.
I forgot to take pictures while soldering, but here is also the fritzing equivalent.
Step 5: Insert It All Inside the Container
I removed some of the silica to make room for the circuit. I also made some holes at the top to access the switch as well as the charging jack. After that I just rammed everything inside, put the lid back and apply glue in it.
Step 6: Put Magnets
To make it hassle free, I then glued on 2 duodenum magnets so I can easily stick it on my bike's metal tubing.
Step 8: Conclusion
I tried using it while biking at night, but it actually fell short as it does not last long. With that very small battery, I was only able to get 30 minutes or less upon every charge. But nevertheless it can still be used in many other ways. With the attached magnets, you can stick it any metal (example: door knob, cabinet handles, etc.).