10.2. WooKey Screen PCB¶

Pinout

10.2.1. Introduction¶

The Wookey from ANSSI is an open source hardware design, implementing an Encrypted Flash Drives.

This repository is aimed towards developers.

10.2.1.1. Revision information¶

This directory contains the hardware design for the Wookey board, first public version (Wookey V2).

### PCB editing tools

All PCB files (schematic and PCB layout) have been designed using the KiCad EDA. This Cross Platform and Open Source Electronics Design Automation Suite can be downloaded on http://kicad-pcb.org/.

10.2.2. Production files generation 101¶

10.2.2.1. Configure the project¶

KiCad binaries location may change regarding your operating system. This is why you have to set your environment. This is done by sourcing the setenv.sh script. This script exports all paths that are required in order to automaticaly generate the production files.

Most of the time, the paths proposed in this script are not the one you use in your specific installation. The setenv.sh script support easy variables overloading by including a setenv.local.sh script file if this file exists in the same directory. If you need to overload some of the variables of the setenv.sh script, just add them to your own setenv.local.sh file. Here is an example to define KiCad environement path on Apple Mac OS.

$ echo "export PYTHON_BIN_PATH = /Applications/KiCad/kicad.app/Contents/Frameworks/Python.framework/Versions/2.7/bin/python" > setenv.local.sh
$ source setenv.sh
Loading local SDK settings...
=========================================================
=== Kicad environment configuration
=========================================================
PYTHON_BIN_PATH   = /Applications/KiCad/kicad.app/Contents/Frameworks/Python.framework/Versions/2.7/bin/python
PYTHON_PATH     = /Applications/Kicad/kicad.app/Contents/Frameworks/python/site-packages
BOM_GEN_PATH = /Applications/Kicad/kicad.app/Contents/SharedSupport/plugins/bom2grouped_csv.xsl
TOOLS_PATH = ../../../tools
=========================================================

The production files can be generated using the following command.

$ make

This will generate the production files in a new sub directory. The directory name may differ according the project your are working with.

10.2.3. PCB Pinout¶

Pinout

10.2.4. PCB Layers¶

10.2.4.1. PCB TOP layer¶

TOP

10.2.4.2. PCB BOTTOM layer¶

BOT

10.2.4.3. Layers¶

Order and type of copper layers: TOP: signal, front components GND: ground plane PWR: ground and power plane BOT: signal, back components

10.2.4.4. Stackup¶

4 layers, 1.6mm thickness Outer layers 1 oz base copper foil Inner layers 0.5 oz base copper foil

Electroless Nickel Immersion Gold (ENIG) surface finish

solder resist 0.0254mm copper 0.0356mm L1 (TOP) FR408 prepreg 0.1702mm copper 0.0178mm L2 (GND) FR408 1.1938mm copper 0.0178mm L3 (PWR) FR408 prepreg 0.1702mm copper 0.0356mm L4 (BOT) solder resist 0.0254mm

The substrate for both the core and prepreg is FR408, with a dielectric constant of 3.66 at 1GHz. The prepreg is comprised of 2 layers of Isola 2113.

10.2.5. Regulatory compliance & handling¶

The Wookey board is intended for use as a development platform for hardware or software. The board is an open system design, which does not include a shielded enclosure. This may cause interference to other electrical or electronic devices in close proximity. In a domestic environment, this product may cause radio interference in which case the user may be required to take adequate measures. In addition, this board should not be used near any medical equipment or RF devices.

The board is sensitive to ESD. Hold the board only by its edges. After removing the board from its box, place it on a grounded, static-free surface.

The board can become hot, like any fan-less design, during continuous high CPU loads, mind its temperature while handling it.

10.2.6. License¶

This is an open hardware design licensed under the terms of the CERN Open Hardware Licence (OHL) v1.2.

You may redistribute and modify this documentation under the terms of the CERN OHL v.1.2 (http://ohwr.org/cernohl). This documentation is distributed WITHOUT ANY EXPRESS OR IMPLIED WARRANTY, INCLUDING OF MERCHANTABILITY, SATISFACTORY QUALITY AND FITNESS FOR A PARTICULAR PURPOSE. Please see the CERN OHL v.1.2 for applicable conditions.