Bike Light Battery Pack Adapter

This entry is part 1 of 3 in the series Bike Light

Design and build of a 540 lumen Luxeon Star Endor Rebel bike light powered by a Makita 18V Li-ion battery (note: I made this while an expat living in China and so was very limited in the materials, parts, and tools available.)

bike_sideThis project is a combination electronic/mechanical design. In fact, there’s a lot more time spent on the mechanical design and machining than in the simple Atmel AVR ┬ÁController. I’ll be presenting this project in three major parts: The battery pack adapter; the light housing; and the AVR control circuit. In the project sources, I provide the full Continue reading

Bike Light Housing

This entry is part 2 of 3 in the series Bike Light

With the battery assembly done, I turned to …

The Light Housing

cad_lightThe Endor Rebel LED generates some heat as we pump 0.7A through it at 9V. Therefore, it needs a heatsink, so that pretty much means the housing we design needs to be made out of Aluminum and needs good physical contact with the LED’s aluminum base. So, again we start with a 3D CAD model. The first thing we need to do is model the actual Rebel LED since everything else grows from there.

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Bike Light Electronics Package

This entry is part 3 of 3 in the series Bike Light

To finish up I needed hardware and firmware.

The Electronics Package

schematicCompared to the machining, the electronics are a piece of cake. I’m using an Atmel AVR ATTiny13 to control the brightness. +5V Power for the ┬ÁController is provided by the BuckPuck, the BuckPuck brightness control pin is driven by a PWM signal generated by the ┬ÁController, and the human interface is a single pushbutton.

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