LED lights and lenses for my bike

I plan to have several strings of LEDs with different beam angles and aiming points - and the appropriate string of LEDs turned on for the current bike speed.

Plan

Project journal is now in dropbox/bikelight/project-bikelight.nb

Project overview and status is here.

Overview

My motivation is to have fun while learning about designing PCBs, and using microcontrollers, MOSFETs and LEDs - with a simple objective to measure my progress against.

I came across this page that explains the benefits of matching LEDs to bike generators.

Since LEDs seem cheap and the available energy is small, I refined the plan. Build several strings of LEDs with different beam angles and aiming points - and the choose the string of LEDs to turn on for the current bike speed and conditions.

Initial target:

generate some diffuse light at low speed
generate more focused light at high speed
make it work
dont break the bank

Advanced target:

during the day, flash the LEDs to attract attention.

In progress lessons

how to use Eagle CAD:
- to make components
- to enter schematic
- to layout a board

Physical progress

Have components, circuit boards, solder paste.

Todo

Software
Solder stencil
Surface mount soldering
Through hole soldering
Testing

Open questions

How to mount and cool the LEDs?
- on a horizontal copper heat pipe
How to mount the circuit board?

Electronics

Plan is now for

four LED strings (*)

- very low speed - just a 120 deg med power LED
- low speed - one 30deg
- med speed - one 30deg, one 15deg
- high speed - one 15deg, two 5deg

LED voltage sense for fine control
light sensor - to allow different night and day policies
JTAG debugging
possible communications via SPI, TWI, ...

(*) the length of the strings depend on the Voltage generated, and will be changed to match.

This easily fits in the attiny84 - with space for JTAG also.

New link on impedance matching and MCU control of bike lights :). I am not sure what this means for my circuit. My plan is to continue on:).

Project:SpeedAdjustableBikeLight