This is actually 2 separate projects utilizing the same code and the same basic wiring. The first is a module case that holds the electronics to control auxiliary brake lights on a motorcycle. the Arduino and adxl345 accelerometer send a signal to a relay whenever you decelerate beyond a certain threshold. This allows for engine braking to trigger a flashing brake light strip mounted on the passenger foot peg brackets. So now when you downshift you don't have to worry about some lazy driver realizing that you are slowing down. I figured that this could also be used to make and independent brake light that could be attached to anything from a moped to a trailer. Please understand that the cases are still in the testing phase and that there will be both parts lists and wiring diagrams to follow. this project is relatively inexpensive and versatile for everything from your ATV to your bicycle.
The box itself is made of ABS or PLA the lids and inserts are made using TPU with no more than 25% infill so that you can slightly compress them I am still working to make the light box water tight. In the original model (seen in the pictures as a yellow brake light) I am toying with some changes to allow for a seal between the light and the box but as of now it is not all weather yet.
There is alot of stuff on the inside of these two projects. the passive brake box is powered by the motorcycle it is wired into but the independent brake light required a power source of it's own so I opted for a 9v battery to directly power the light through the relay I did this because I didn't really want to deal with two regulators getting hot inside the box. I since added the guts from a cheap solar phone battery bank to make the electronics power source capable of both charging your phone (for on a bicycle) and also being rechargeable itself. All the electronics including the light only draw about .45 amps so if you would rather have one power source it would be a pretty simple matter. There will be wiring diagrams and code to follow over the next several days. If you have any ideas or questions please don't hesitate to ask.