2 # Copyright 2024 by Bdale Garbee <bdale@gag.com>. GPLv3
4 # emit PCB footprint for QFN-44 package used by ATmega32U4
5 # - leaving out the under-chip pad as it's not necessary
8 # dimensions in mm from
9 # atmel/samd21/ATmega32U4.pdf
13 RowSpacing = 6.9 # C1 / C2
16 GndSquare = 5.20 # X2 / Y2
18 PinClearance = 2 * (PinSpacing - PinWidth)
20 # ATMEL specifies 120-150 microns between pad and solder mask
21 # AT88RF1354 Appplication note .. should be good here too?
23 PinResist = PinWidth + (2 * 0.07)
25 # we're going to use the 1/100 of a mil fundamental unit form
28 return int( mm / 25.4 * 1000.0 * 100.0 + 0.5 )
30 print('# author: Bdale Garbee')
31 print('# email: bdale@gag.com')
32 print('# dist-license: GPL 3')
33 print('# use-license: unlimited')
35 print('Element[0x0 "qfn-44" "" "" 0 0 0 0 0 100 0x0]')
39 for pin in range (1,12):
41 mm2mils100((-6 + pin) * PinSpacing), \
42 mm2mils100(-RowSpacing/2 - PinHeight/2 + PinWidth/2), \
43 mm2mils100((-6 + pin) * PinSpacing), \
44 mm2mils100(-RowSpacing/2 + PinHeight/2 - PinWidth/2), \
45 mm2mils100(PinWidth), \
46 mm2mils100(PinClearance), \
47 mm2mils100(PinResist), \
48 '"pin%i"' % (34-pin), '"%i"' % (34-pin), '0x0000]')
51 mm2mils100((-6 + pin) * PinSpacing), \
52 mm2mils100(RowSpacing/2 - PinHeight/2 + PinWidth/2), \
53 mm2mils100((-6 + pin) * PinSpacing), \
54 mm2mils100(RowSpacing/2 + PinHeight/2 - PinWidth/2), \
55 mm2mils100(PinWidth), \
56 mm2mils100(PinClearance), \
57 mm2mils100(PinResist), \
58 '"pin%i"' % pin, '"%i"' % pin, '0x0000]')
61 mm2mils100(-RowSpacing/2 - PinHeight/2 + PinWidth/2), \
62 mm2mils100((-6 + pin) * PinSpacing), \
63 mm2mils100(-RowSpacing/2 + PinHeight/2 - PinWidth/2), \
64 mm2mils100((-6 + pin) * PinSpacing), \
65 mm2mils100(PinWidth), \
66 mm2mils100(PinClearance), \
67 mm2mils100(PinResist), \
68 '"pin%i"' % (33+pin), '"%i"' % (33+pin), '0x0000]')
71 mm2mils100(RowSpacing/2 - PinHeight/2 + PinWidth/2), \
72 mm2mils100((-6 + pin) * PinSpacing), \
73 mm2mils100(RowSpacing/2 + PinHeight/2 - PinWidth/2), \
74 mm2mils100((-6 + pin) * PinSpacing), \
75 mm2mils100(PinWidth), \
76 mm2mils100(PinClearance), \
77 mm2mils100(PinResist), \
78 '"pin%i"' % (23-pin), '"%i"' % (23-pin), '0x0000]')
80 print(' ElementArc[',\
81 mm2mils100(-Overall/2 - PinWidth), \
82 mm2mils100(Overall/2 + PinWidth), \
83 '500 500 0 360 1000 ]')