Duncan Drennan wrote:
This was about the angle theta. Well, I thought this could and should be defined relative to the board alone, same as the X/Y coordinates. All other geometry of the fab is unknown. What I lack here, is a definition like "Theta is measured relative to the positive X-axis. Looking at the component side positive theta is counter clockwise". Immediately evidentI think so, but it's unreliable because we just guess. The assembly house will most likely massage the data anyway.It is actually fairly accurate, but it depends on the component orientation in a reel. The assembly house will definitely massage the data, but they can't necessarily be trusted either...
is the question, where the X-axis is in a footprint. Admittedly I didn't care about this with the few footprints I made so far. With package geometies that show symmetry like DIP and/or are elongated, it could be recommended to use the longest symmetry axis as X. For quadratic packages like QFP, axes parallel to the edges of the part and placing pin 1 in the first quadrant is an option - in some datasheets pin 1 is top left though, which would be quadrant 2. Information like this a candidate for the database as well (whether/how the CS of a given footprint deviates from above).Did I miss this in the documentation? - think this should go into the primers.
Regards, Armin _______________________________________________ geda-user mailing list geda-user@xxxxxxxxxxxxxx http://www.seul.org/cgi-bin/mailman/listinfo/geda-user