Electronic Design for the Velo Bling-Bling Project

LED lights for bicycle wheels. 16 multi color LEDs on both sides (PCB top- and bottom side). There are two windows (upper and lower) on both sides for display dynamic information like speed, trip time, trip distance, etc. or static information like strings and images.

The Printed Circuit Board (PCB) is free hardware. The PCB is a multi-layer (4 layer) 160 x 30.5 x 1.6 mm FR4 board. The firmware for the MK22DX256VLF5 MCU is also on GitHub.

There is also an optional Bluetooth Low Energy (Smart) subsystem on board. It is a LAIRD BL652-SA module (before v2.3 BL600-SA). The Bluetooth application software is on GitHub too.

It is possible to mount the PCB direct onto the wheel spokes but it is better to use a mounting frame. This frame can be ordered from http://shapeways.com or you can print it by yourself on 3D printer. See FrameDesign and GitHub.

Copyright

Peter Schmid, Zurich Switzerland, peter@spyr.ch

This work (electronic design) is licensed under a Creative Commons Attribution-ShareAlike 4.0 International Public License. To view a copy of this license, visit http://creativecommons.org/licenses/by-sa/4.0/ or send a letter to Creative Commons, 171 Second Street, Suite 300, San Francisco, California, 94105, USA.

Velo Bling-Bling by Peter Schmid is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

Schematics

PCB Layout

Bill of Material

Get the CAE Data and Change the Design

Get the CAE Data from the Repository

https://github.com/spyren/veloblingbling-pcb

ZIP-File

clone the repository

psi@homer:~/veloblingbling/pcb> git clone https://github.com/spyren/veloblingbling-pcb
Klone nach 'veloblingbling-pcb' ...
remote: Counting objects: 265, done.
remote: Compressing objects: 100% (97/97), done.
remote: Total 265 (delta 167), reused 260 (delta 166), pack-reused 0
Empfange Objekte: 100% (265/265), 223.50 KiB | 0 bytes/s, Fertig.
Löse Unterschiede auf: 100% (167/167), Fertig.
Prüfe Konnektivität ... Fertig.
psi@homer:~/veloblingbling/pcb>

EAGLE PCB Design Tool

EAGLE from CadSoft is not free software. But there is a Light Edition. With this edition you can at least view and print the drawings. The design exceeds the limits (100 x 80 mm board size) for the Light Edition, therefore you can not edit/change this design. There is also EAGLE Make Personal edition, with this edition (140 €) you can edit the design (restricted to non commercial use). See EAGLE Pricing Table for other licenses.

Maybe the free KiCad or fritzing can be used to import the design.

How To Order PCBs

I ordered my PCBs from PCB-POOL, they accept the EAGLE design files (e.g. ewheel32.brd) and you do not have to generate you own Gerber and Excellon drill files.

Some ordering information:

• Length in mm: 160
• Width in mm: 30
• File format: EAGLE
• Base material: FR4, 35 µm Cu, 1,6 mm
• Soldermask: inclusive
• Position print / Silkscreen: yes, TOP and BOTTOM
• The price includes silkscreen for 36.65 EUR
• Surface: ENIG (Electroless Nickel Gold) for ultra-flat pads
• Min. track / gap size: >= 0.150 mm (6 mil)
• Min. drill-end diameter: >= 0.3 mm (12 mil)
• E Test inclusive
• Free Stencil: yes

Snap-away Controller/LED Board

If do not need the LEDs you can use the controller board without it, just snap-off the LED part.

Or vice versa if you want to use the LEDs for another controller board. The controller can switch on and off the LEDs over a Serial Peripheral Interface (SPI) bus. The controller is the master, the LEDs on top and bottom side are arranged as slaves.

Pin-Header X5/X6: