xbrd - Expansion board design for M1r4 (and beyond)
===================================================

This is only a draft and may change quite a bit in the future.

Top view:
http://downloads.qi-hardware.com/people/werner/tmp/xbrd-top.pdf

The parameters are as follows:

Label   Description                             Type    Value
------- --------------------------------------- ------- -------
B       Baseline between J21 and Jxx            typ     45 mm
CB      Clearance, back                         max     22 mm
CF      Clearance, front                        max     10 mm
CL      Clearance, left (seen from front)       max      5 mm
CR      Clearance, right (seen from front)      max     15 mm
FB      Baseline to front wall                  typ     15 mm
FW      Front wall thickness                    typ      3 mm
HL      Header length (long side)               typ     900 mil
HW      Header width (short side)               typ     200 mil

In the drawing, all dimensions are in mm.

Typical dimensions would be things we decide in the design.

Maximum dimensions would be limits for the expansion board
designer (e.g., to avoid bumping into other components or
walls).

Unlabeled dimensions are calculated from the parameters and
have only an informational character.
