Orone-mini-S8H-v0r001
Copyright 2013 G Bulmer

This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.
I ask that my name remain visible in the copper.

The pin headers are standard 'breadboard friendly' 0.1" pitch.
The two rows of pin headers are 0.8" apart, and hence fit a single breadboard.
The board is 2.4" long x 1" high. Most components are 1206 or larger.

1206 components are too big to fit in mini 2.1" length. 
Further 8mil track/8mil clearance required more board area
Hence the board is lengthened from 2.1" to 2.4"
Like other Orone-mini, 1206 C1 is replaced with 7343-case size

Design Rules: OSHPark.com & Seeedstudio 'Fusion' PCB Service

Routing
Crystal tracks & Top Layer MCU tracks are 8mil/8mil to enable a wider range of PCB manufacturers to reliably make the board.
All tracks from thru-hole (hand soldered) components, except pin headers, are 10mil or wider. This is intended to make the tracks more robust.

All Bottom Layer tracks are 10mil or bigger, except Crystal tracks; this is intended to be easier to make reliably.

Vias: The three via shapes are used to give information, and help 'read' the PCB.
VIA KEY
SQUARE:  Digital Ground (DGND) and thermal vias
ROUND:   Signal
OCTAGON: Power (e.g. Vcc) or segregated Ground (e.g. AGND) and one ground via

Notes
There are four Hidden Airwires, which do not need routing (replicated on switches)
For safety, type 'RATSNEST *' to make them visible before making any changes
Two pads 33 and DISC, printed at 45 degrees, are signals, not for components.
DRC->Restring Pads & Vias minimum increased from OSHPark 7mil to 10mil to support more PCB manufacturers design rules by providing larger annular rings.

Ventosus found the ADC was significantly 'noisier' than Maple-mini. So the ADC tracks are more thoroughly separated from other tracks.