Bike Kinect Light


A friend ask if i can do a light to bicycle that have accelerometer and other features.

After digging deep in internet, found some lights from eBay that can adapt.

100 Lumen, USB Rechargeable, COB Led, 600mA/h Lithium Battery


So i decide to start doing schematic.

  • Microcontroller will be MDBT40 (nRF51822) with BLE.
  • ADXL345 accelerometer with 2 configured interrupts (Activity and Inactivity).
  • MAX17043 Battery Fuel Gauge
  • LT3517 Full-Featured LED Driver with 1.5A Switch Current
  • Micro SD Card Connector, never now what metrics we what to get :)

My idea is to have BLE for configure Modes of working light (Constant, Blink, Accelerometer, Battery Saving).

With low power alert.

And try to minimize current consumption to minimum, providing at least 20 hours using Blink Mode.

The others modes maybe 5 to 10 hours.

As i don't have light from eBay, maybe need to had buck/boost regulator.

And another great thing, but not decided yet is add Qi Receiver, just to charge battery without usb connector. A nice to have !!!

Schematic and PCB is on the way, but finished.

As light is too small, PCB for now have about 50mmx25mm.

After testing this size is good for panelize with seeedstudion 100mmx100mm (8 boards) with v-cut.

Next post/update will put schematic and pcb.

Schematic (Autodesk Eagle):

BOM list:

PCB (Autodesk Eagle):

Build & Assembled:

Code & Testing:

Resources & Related Links: