+#!/usr/bin/python
+# Copyright 2011 by Bdale Garbee <bdale@gag.com>. GPLv2
+# Copyright 2019 by Keith Packard <keithp@keithp.com>. GPLv2+
+#
+# Program to emit PCB footprint for WQFN-16 package used by the DRV8800
+#
+
+# dimensions in mm from the DRV8800
+
+PinWidth = 0.3 # b
+PinHeight = 0.95 # L
+PinSpacing = 0.65 # e
+Overall = 4.75 # E
+GndSquare = 2.1 # D2 & E2
+CoreSquare = 2.1
+PinClearance = 2 * (PinSpacing - PinWidth)
+
+# ATMEL specifies 120-150 microns between pad and solder mask
+# AT88RF1354 Appplication note
+#
+PinResist = PinWidth + (2 * 0.07)
+
+import sys
+
+# we're going to use the 1/100 of a mil fundamental unit form
+
+def mm2mils100( mm ):
+ return int( mm / 25.4 * 1000.0 * 100.0 + 0.5 )
+
+print '# author: Keith Packard'
+print '# email: keithp@keithp.com'
+print '# dist-license: GPL 2'
+print '# use-license: unlimited'
+
+print 'Element[0x0 "qfn-16" "" "" 0 0 0 0 0 100 0x0]'
+print "("
+
+# pad under the chip, must be grounded
+print ' Pad[',\
+ mm2mils100(0), \
+ mm2mils100(0), \
+ mm2mils100(0), \
+ mm2mils100(0), \
+ mm2mils100(GndSquare), \
+ mm2mils100(PinClearance), \
+ mm2mils100(PinResist), \
+ '"pin17" "17" "square,nopaste"]'
+
+# vias in the ground pad under the chip
+for viarow in range (-1,1):
+ for viacol in range (-1,1):
+ print ' Pin[',\
+ mm2mils100(1.8 * viacol * CoreSquare / 3 + .9 * CoreSquare/3), \
+ mm2mils100(1.8 * viarow * CoreSquare / 3 + .9 * CoreSquare/3), \
+ 2600, \
+ 2500, \
+ 0, \
+ 1300, \
+ '"pin17" "17" 0x0002]'
+
+# break pad under chip into a grid to control the resist and paste masks
+
+blocks=3;
+
+for viarow in range (-1, 2):
+ for viacol in range (-1, 2):
+ if (viarow in (-1, 1)) and (viacol in (-1, 1)):
+ # copper sub-square with resist over vias
+ print ' Pad[',\
+ mm2mils100(viacol * CoreSquare / blocks), \
+ mm2mils100(viarow * CoreSquare / blocks), \
+ mm2mils100(viacol * CoreSquare / blocks), \
+ mm2mils100(viarow * CoreSquare / blocks), \
+ mm2mils100((CoreSquare)/blocks), \
+ 0, \
+ 0, \
+ '"pin17" "17" "square,nopaste"]'
+ else:
+ # copper sub-square without resist
+ print ' Pad[',\
+ mm2mils100(viacol * CoreSquare / blocks), \
+ mm2mils100(viarow * CoreSquare / blocks), \
+ mm2mils100(viacol * CoreSquare / blocks), \
+ mm2mils100(viarow * CoreSquare / blocks), \
+ mm2mils100((CoreSquare)/blocks), \
+ 0, \
+ mm2mils100((CoreSquare)/blocks), \
+ '"pin17" "17" "square,nopaste"]'
+ # copper spot to control paste mask generation
+ print ' Pad[',\
+ mm2mils100(viacol * CoreSquare / blocks), \
+ mm2mils100(viarow * CoreSquare / blocks), \
+ mm2mils100(viacol * CoreSquare / blocks), \
+ mm2mils100(viarow * CoreSquare / blocks), \
+ 1500, \
+ 0, \
+ mm2mils100((CoreSquare)/blocks), \
+ '"pin17" "17" "square"]'
+
+# pins
+for pin in range (1,5):
+ print ' Pad[',\
+ mm2mils100((-2.5 + pin) * PinSpacing), \
+ mm2mils100(-Overall/2 + PinWidth/2), \
+ mm2mils100((-2.5 + pin) * PinSpacing), \
+ mm2mils100(-Overall/2 + PinHeight - PinWidth/2), \
+ mm2mils100(PinWidth), \
+ mm2mils100(PinClearance), \
+ mm2mils100(PinResist), \
+ '"pin%i"' % (13-pin), '"%i"' % (13-pin), '0x0000]'
+
+ print ' Pad[',\
+ mm2mils100((-2.5 + pin) * PinSpacing), \
+ mm2mils100(+Overall/2 - PinHeight + PinWidth/2), \
+ mm2mils100((-2.5 + pin) * PinSpacing), \
+ mm2mils100(+Overall/2 - PinWidth/2), \
+ mm2mils100(PinWidth), \
+ mm2mils100(PinClearance), \
+ mm2mils100(PinResist), \
+ '"pin%i"' % pin, '"%i"' % pin, '0x0000]'
+
+ print ' Pad[',\
+ mm2mils100(Overall/2 - PinHeight + PinWidth/2), \
+ mm2mils100((-2.5 + pin) * PinSpacing), \
+ mm2mils100(Overall/2 - PinWidth/2), \
+ mm2mils100((-2.5 + pin) * PinSpacing), \
+ mm2mils100(PinWidth), \
+ mm2mils100(PinClearance), \
+ mm2mils100(PinResist), \
+ '"pin%i"' % (9-pin), '"%i"' % (9-pin), '0x0000]'
+
+ print ' Pad[',\
+ mm2mils100(-Overall/2 + PinWidth/2), \
+ mm2mils100((-2.5 + pin) * PinSpacing), \
+ mm2mils100(-Overall/2 + PinHeight - PinWidth/2), \
+ mm2mils100((-2.5 + pin) * PinSpacing), \
+ mm2mils100(PinWidth), \
+ mm2mils100(PinClearance), \
+ mm2mils100(PinResist), \
+ '"pin%i"' % (12+pin), '"%i"' % (12+pin), '0x0000]'
+
+print ' ElementArc[',\
+ mm2mils100(-2.0), \
+ mm2mils100(2.0), \
+ '500 500 0 360 1000 ]'
+print ")"