Electronic Design (Schematics and PCB Layout)

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.


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.

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




PCB Layout


Bill of Material

Qty Value Package Parts Description Farnell Mouser Distrelec
2 33 R0805 R54, R55 Resistor   667-ERJ-P6WF33R0V  
96 220 R0805 R2, R3, .. R111 Resistor 2008374 667-ERJ-6ENF2200V  
3 4.7k R0805 R51, R61, R62 Resistor   667-ERA-6AEB472V  
2 10k R0805 R57, R112 Resistor   667-ERJ-6ENF1002V  
5 100k R0805 R49, R52, R53, R59, R60 Resistor   667-ERJ-6ENF1003V  
1 1.0M R0805 R1 Resistor   667-ERA-6AEB105V  
2 12p C0805 C9, C10 Capacitor   581-08055A120J  
2 22p C0805 C12, C13 Capacitor 1759195 80-C0805C220J1G 831416
12 100n C0805 C3, C5, C7, C8, C14, C15, C17, C20, C24, C26, C27, C28 Capacitor   81-GRM40X104K50L  
12 4.7u C0805 C1, C2, C4, C6, C16, C18, C19, C21, C22, C23, C25 Capacitor   81-GCM21BR71C475KA3L  
2 330 L1206 R50, R63 EMI Filter 330 Ohm, 3A 1635756 710-742792121  
1 32.768kHz ABS07 Q1 Quartz 2101347 815-ABS07-32.768KHZT  
1 8MHz ABM3B Q2 Quartz 2467818RL 815-ABM3B-8.0-B2-T  
2 BAT54C SOT23 D3, D4 Dual Schottky Diodes 1621834 512-BAT54C  
2 GSOT05C-!E308 SOT23 D1, D2 Dual Diode TVS 2355439 78-GSOT05C-E3-08 605685
32 CLV1A-FKB PLCC4 LD1, LD2, .. LD32 RGB LED 2430039RL 941-V1AFKBCHMKPEH7A3  
1 MK22DX256VLF5 QFP-48N U1 MCU, KINETIS K22   841-MK22DX256VLF5  
1 LAIRD BL652-SA BL652 U5 Bluetooth Module 2664536 239-BL652-SA  
12 MC74HC595ADTR2G SOP-16N U6, U7, .. U17 8-Bit Serial-In Shift Register 2425499 863-MC74HC595ADTR2G 649594
1 MCP73832T-2ACI/OT SOT-5N U4 Charge Management Controller 1332159 579-MCP73832T-2ACIOT  
1 A3213LH SOT23-W U18 Linear Hall Effect Sensor 1457117    
1 MMA8451QR1 QFN-16N U3 3-Axis, Digital Accelerometer 1842359 841-MMA8451QR1  
1 MPL3115A2 DFN-8N U2 Pressure Sensor, 20-110KPA 2009084 841-MPL3115A2  
2 PIN-HEADER 2-5 2-5-SMD X1, X2 Pin Header 2x5 1/20" 1022310 855-M50-3600542 127196
1 MICRO-USB ZX62R-B-5P X4 Hirose Micro USB Connector 2300439 798-ZX62R-B-5P  
1 B3S-1002 B3S-1000 S1 Push Button 959728 653-B3S-1002  

Get the CAE Data and Change the Design

Get the CAE Data from the Repository

The Velo Bling-Bling electronic design project is on the GitHub repository https://github.com/spyren/veloblingbling-pcb. Download the ZIP-File and unzip it or better clone the repository e.g. for GNU/Linux:
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.

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:

Pin# SPI Signal
1 (OE)
2 SS- top
3 SS- bottom
4 (RESET-)


-- Peter Schmid - 2016-03-30


Topic attachments
I Attachment History Action Size Date Who Comment
PNGpng ewheel32-sch-1-small.png r2 r1 manage 223.1 K 2016-11-12 - 20:30 PeterSchmid  
PNGpng ewheel32-sch-1.png r2 r1 manage 204.5 K 2016-11-12 - 20:24 PeterSchmid  
PNGpng ewheel32-sch-2-small.png r2 r1 manage 284.0 K 2016-11-12 - 20:30 PeterSchmid  
PNGpng ewheel32-sch-2.png r2 r1 manage 211.3 K 2016-11-12 - 20:24 PeterSchmid  
PNGpng ewheel32-small.png r2 r1 manage 244.4 K 2016-11-12 - 20:34 PeterSchmid  
PNGpng ewheel32.png r2 r1 manage 147.1 K 2016-11-12 - 20:34 PeterSchmid  
JPEGjpg snap-away-s.jpg r1 manage 137.6 K 2016-11-13 - 08:53 PeterSchmid  
JPEGjpg snap-away.jpg r1 manage 614.4 K 2016-11-13 - 08:53 PeterSchmid  
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Topic revision: r14 - 2016-12-10 - PeterSchmid
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