diff --git a/m1/xbrd/README b/m1/xbrd/README new file mode 100644 index 0000000..737c73f --- /dev/null +++ b/m1/xbrd/README @@ -0,0 +1,32 @@ +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 25 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.