In the "Files" section you can find the "FunKey Rev. A.zip" file containing all the source files making up FunKey's electronic design.

The whole design is done using KiCAD release 5.0.0-rc3-unknown-14ce5182~65ubuntu16.04.1, but it should work with all KiCAD > 5.0.0 on all platforms.

Besides the schematic and layout files, this archive contains the schematic symbol and footprint libraries, as well as all the project-specific 3D parts in STEP format.

As a bonus, the archives contains too the BOM in both CSV and LibrOffice Calc .formats, as well as an interactive BOM generated by the InteractiveHtmlBom tool. This file is very handy if you need to pick & place components manually with tweezers.

Please note that this archive contains the file for revision A which has been prototyped with PCBs ordered with stencils from JLC PCB and almost all components sourced from Mouser (except for the Chinese micro USB connector and a few parts that were momentarily out of stock). The only bug we found besides bad solder joints was a BOM mistake for R11: it should be a 240R 1% 0402 resistor instead of a 240k. This resistor is used to calibrate the DRAM data/clock skew and its value is critical.

We anticipate a revision B that will correct this (small) BOM mistake, as well as some other minor concerns:

• increase the current limiting resistor for the LED R26 to reduce the light intensity
• swap the battery and screen connectors J5 and J3 to simplify the screen flex design
• drive the screen RESET signal from a CPU (U3) GPIO rather than automatically from the PMIC (U5)
• find a way to solder the loudspeaker using a better method: currently, we use through-hole resistor legs to solder the speaker to the PCB 8-)
• increase the test pad diameter from 0.5 mm to 1 mm, they are way too small today