pcb.py

      self.shape = add(self.shape,translate(pad_TQFP_v,-d,-c,0))
      self.pad.append(point(-d,-c,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'PD7'))
      #
      # pin 17: VCC
      #
      self.shape = add(self.shape,translate(pad_TQFP_v,0,-c,0))
      self.pad.append(point(0,-c,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'VCC'))
      #
      # pin 18: GND
      #
      self.shape = add(self.shape,translate(pad_TQFP_v,d,-c,0))
      self.pad.append(point(d,-c,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'GND'))
      #
      # pin 19: PC0/PCINT16/SCL
      #
      self.shape = add(self.shape,translate(pad_TQFP_v,2*d,-c,0))
      self.pad.append(point(2*d,-c,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'PC0'))
      #
      # pin 20: PC1/PCINT17/SDA
      #
      self.shape = add(self.shape,translate(pad_TQFP_v,3*d,-c,0))
      self.pad.append(point(3*d,-c,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'PC1'))
      #
      # pin 21: PC2/PCINT18/TCK
      #
      self.shape = add(self.shape,translate(pad_TQFP_v,4*d,-c,0))
      self.pad.append(point(4*d,-c,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'PC2'))
      #
      # pin 22: PC3/PCINT19/TMS
      #
      self.shape = add(self.shape,translate(pad_TQFP_v,5*d,-c,0))
      self.pad.append(point(5*d,-c,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'PC3'))
      #
      # pin 23: PC4/TDO/PCINT20
      #
      self.shape = add(self.shape,translate(pad_TQFP_h,c,-5*d,0))
      self.pad.append(point(c,-5*d,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'PC4'))
      #
      # pin 24: PC5/TDI/PCINT21
      #
      self.shape = add(self.shape,translate(pad_TQFP_h,c,-4*d,0))
      self.pad.append(point(c,-4*d,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'PC5'))
      #
      # pin 25: PC6/TOSC1/PCINT22
      #
      self.shape = add(self.shape,translate(pad_TQFP_h,c,-3*d,0))
      self.pad.append(point(c,-3*d,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'PC6'))
      #
      # pin 26: PC7/TOSC2/PCINT23
      #
      self.shape = add(self.shape,translate(pad_TQFP_h,c,-2*d,0))
      self.pad.append(point(c,-2*d,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'PC7'))
      #
      # pin 27: AVCC
      #
      self.shape = add(self.shape,translate(pad_TQFP_h,c,-d,0))
      self.pad.append(point(c,-d,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'AVCC'))
      #
      # pin 28: GND
      #
      self.shape = add(self.shape,translate(pad_TQFP_h,c,0,0))
      self.pad.append(point(c,0,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'GND'))
      #
      # pin 29: AREF
      #
      self.shape = add(self.shape,translate(pad_TQFP_h,c,d,0))
      self.pad.append(point(c,d,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'AREF'))
      #
      # pin 30: PA7/ADC7/PCINT7
      #
      self.shape = add(self.shape,translate(pad_TQFP_h,c,2*d,0))
      self.pad.append(point(c,2*d,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'PA7'))
      #
      # pin 31: PA6/ADC6/PCINT6
      #
      self.shape = add(self.shape,translate(pad_TQFP_h,c,3*d,0))
      self.pad.append(point(c,3*d,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'PA6'))
      #
      # pin 32: PA5/ADC5/PCINT5
      #
      self.shape = add(self.shape,translate(pad_TQFP_h,c,4*d,0))
      self.pad.append(point(c,4*d,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'PA5'))
      #
      # pin 33: PA4/ADC4/PCINT4
      #
      self.shape = add(self.shape,translate(pad_TQFP_h,c,5*d,0))
      self.pad.append(point(c,5*d,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'PA4'))
      #
      # pin 34: PA3/ADC3/PCINT3
      #
      self.shape = add(self.shape,translate(pad_TQFP_v,5*d,c,0))
      self.pad.append(point(5*d,c,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'PA3'))
      #
      # pin 35: PA2/ADC2/PCINT2
      #
      self.shape = add(self.shape,translate(pad_TQFP_v,4*d,c,0))
      self.pad.append(point(4*d,c,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'PA2'))
      #
      # pin 36: PA1/ADC1/PCINT1
      #
      self.shape = add(self.shape,translate(pad_TQFP_v,3*d,c,0))
      self.pad.append(point(3*d,c,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'PA1'))
      #
      # pin 37: PA0/ADC0/PCINT0
      #
      self.shape = add(self.shape,translate(pad_TQFP_v,2*d,c,0))
      self.pad.append(point(2*d,c,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'PA0'))
      #
      # pin 38: VCC
      #
      self.shape = add(self.shape,translate(pad_TQFP_v,d,c,0))
      self.pad.append(point(d,c,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'VCC'))
      #
      # pin 39: GND
      #
      self.shape = add(self.shape,translate(pad_TQFP_v,0,c,0))
      self.pad.append(point(0,c,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'GND'))
      #
      # pin 40: PB0/XCK0/T0/PCINT8
      #
      self.shape = add(self.shape,translate(pad_TQFP_v,-d,c,0))
      self.pad.append(point(-d,c,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'PB0'))
      #
      # pin 41: PB1/T1/CLKO/PCINT9
      #
      self.shape = add(self.shape,translate(pad_TQFP_v,-2*d,c,0))
      self.pad.append(point(-2*d,c,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'PB1'))
      #
      # pin 42: PB2/AIN0/INT2/PCINT10
      #
      self.shape = add(self.shape,translate(pad_TQFP_v,-3*d,c,0))
      self.pad.append(point(-3*d,c,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'PB2'))
      #
      # pin 43: PB3/AIN1/OC0A/PCINT11
      #
      self.shape = add(self.shape,translate(pad_TQFP_v,-4*d,c,0))
      self.pad.append(point(-4*d,c,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'PB2'))
      #
      # pin 44: PB4/-SS/OC0B/PCINT12
      #
      self.shape = add(self.shape,translate(pad_TQFP_v,-5*d,c,0))
      self.pad.append(point(-5*d,c,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'PB4'))

TSSOP_pad_width = 0.040
TSSOP_pad_height = 0.011
TSSOP_pad_dy = 0.026
TSSOP_pad_dx = 0.120
pad_TSSOP = cube(-TSSOP_pad_width/2.0,TSSOP_pad_width/2.0,-TSSOP_pad_height/2.0,TSSOP_pad_height/2.0,0,0)

class TRC102(part):
   #
   # RFM TRC102 ISM transceiver
   #
   def __init__(self,value=''):
      self.value = value
      self.pad = [point(0,0,0)]
      self.labels = []
      #
      # pin 1: SDI
      #
      self.shape = translate(pad_TSSOP,-TSSOP_pad_dx,3.5*TSSOP_pad_dy,0)
      self.pad.append(point(-TSSOP_pad_dx,3.5*TSSOP_pad_dy,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'1 SDI'))
      #
      # pin 2: SCK
      #
      self.shape = add(self.shape,translate(pad_TSSOP,-TSSOP_pad_dx,2.5*TSSOP_pad_dy,0))
      self.pad.append(point(-TSSOP_pad_dx,2.5*TSSOP_pad_dy,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'SCK'))
      #
      # pin 3: nCS
      #
      self.shape = add(self.shape,translate(pad_TSSOP,-TSSOP_pad_dx,1.5*TSSOP_pad_dy,0))
      self.pad.append(point(-TSSOP_pad_dx,1.5*TSSOP_pad_dy,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'nCS'))
      #
      # pin 4: SDO
      #
      self.shape = add(self.shape,translate(pad_TSSOP,-TSSOP_pad_dx,0.5*TSSOP_pad_dy,0))
      self.pad.append(point(-TSSOP_pad_dx,0.5*TSSOP_pad_dy,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'SDO'))
      #
      # pin 5: IRQ
      #
      self.shape = add(self.shape,translate(pad_TSSOP,-TSSOP_pad_dx,-0.5*TSSOP_pad_dy,0))
      self.pad.append(point(-TSSOP_pad_dx,-0.5*TSSOP_pad_dy,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'IRQ'))
      #
      # pin 6: DATA/nFSEL
      #
      self.shape = add(self.shape,translate(pad_TSSOP,-TSSOP_pad_dx,-1.5*TSSOP_pad_dy,0))
      self.pad.append(point(-TSSOP_pad_dx,-1.5*TSSOP_pad_dy,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'DATA'))
      #
      # pin 7: CR
      #
      self.shape = add(self.shape,translate(pad_TSSOP,-TSSOP_pad_dx,-2.5*TSSOP_pad_dy,0))
      self.pad.append(point(-TSSOP_pad_dx,-2.5*TSSOP_pad_dy,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'CR'))
      #
      # pin 8: CLKOUT
      #
      self.shape = add(self.shape,translate(pad_TSSOP,-TSSOP_pad_dx,-3.5*TSSOP_pad_dy,0))
      self.pad.append(point(-TSSOP_pad_dx,-3.5*TSSOP_pad_dy,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'CLKOUT'))
      #
      # pin 9: Xtal/Ref
      #
      self.shape = add(self.shape,translate(pad_TSSOP,TSSOP_pad_dx,-3.5*TSSOP_pad_dy,0))
      self.pad.append(point(TSSOP_pad_dx,-3.5*TSSOP_pad_dy,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'Xtal'))
      #
      # pin 10: RESET
      #
      self.shape = add(self.shape,translate(pad_TSSOP,TSSOP_pad_dx,-2.5*TSSOP_pad_dy,0))
      self.pad.append(point(TSSOP_pad_dx,-2.5*TSSOP_pad_dy,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'RESET'))
      #
      # pin 11: GND
      #
      self.shape = add(self.shape,translate(pad_TSSOP,TSSOP_pad_dx,-1.5*TSSOP_pad_dy,0))
      self.pad.append(point(TSSOP_pad_dx,-1.5*TSSOP_pad_dy,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'GND'))
      #
      # pin 12: RF_P
      #
      self.shape = add(self.shape,translate(pad_TSSOP,TSSOP_pad_dx,-0.5*TSSOP_pad_dy,0))
      self.pad.append(point(TSSOP_pad_dx,-0.5*TSSOP_pad_dy,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'RF_P'))
      #
      # pin 13: RF_N
      #
      self.shape = add(self.shape,translate(pad_TSSOP,TSSOP_pad_dx,0.5*TSSOP_pad_dy,0))
      self.pad.append(point(TSSOP_pad_dx,0.5*TSSOP_pad_dy,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'RF_N'))
      #
      # pin 14: VDD
      #
      self.shape = add(self.shape,translate(pad_TSSOP,TSSOP_pad_dx,1.5*TSSOP_pad_dy,0))
      self.pad.append(point(TSSOP_pad_dx,1.5*TSSOP_pad_dy,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'VDD'))
      #
      # pin 15: RSSIA
      #
      self.shape = add(self.shape,translate(pad_TSSOP,TSSOP_pad_dx,2.5*TSSOP_pad_dy,0))
      self.pad.append(point(TSSOP_pad_dx,2.5*TSSOP_pad_dy,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'RSSIA'))
      #
      # pin 16: nINT/DDET
      #
      self.shape = add(self.shape,translate(pad_TSSOP,TSSOP_pad_dx,3.5*TSSOP_pad_dy,0))
      self.pad.append(point(TSSOP_pad_dx,3.5*TSSOP_pad_dy,0))
      self.labels.append(self.text(self.pad[-1].x,self.pad[-1].y,self.pad[-1].z,'nINT'))

class CBA(part):
   #
   # CBA logo
   #
   def __init__(self,r=.02):
      self.value = ''
      self.pad = [point(0,0,0)]
      self.labels = []
      d = 3*r
      self.shape = cylinder(0,0,0,0,r)
      self.shape = add(self.shape,translate(cylinder(0,0,0,0,r),-d,d,0))
      self.shape = add(self.shape,translate(cube(-r,r,-r,r,0,0),-d,0,0))
      self.shape = add(self.shape,translate(cube(-r,r,-r,r,0,0),-d,-d,0))
      self.shape = add(self.shape,translate(cube(-r,r,-r,r,0,0),0,-d,0))
      self.shape = add(self.shape,translate(cube(-r,r,-r,r,0,0),d,-d,0))
      self.shape = add(self.shape,translate(cube(-r,r,-r,r,0,0),d,0,0))
      self.shape = add(self.shape,translate(cube(-r,r,-r,r,0,0),d,d,0))
      self.shape = add(self.shape,translate(cube(-r,r,-r,r,0,0),0,d,0))

class fab(part):
   def __init__(self,r=.05):
      self.value = ''
      self.pad = [point(0,0,0)]
      self.labels = []
      d = 1.8*r
      l = 3.5*r
      h = r/2.
      self.shape = rectangle(-d,d,-d,d)
      self.shape = subtract(self.shape,circle(0,0,r))
      self.shape = subtract(self.shape,rectangle(-l,0,-h,h))
      self.shape = add(self.shape,rectangle(d,l,-h,h))
      self.shape = add(self.shape,circle(l,0,r))
      self.shape = add(self.shape,circle(-l,0,r))

############################################################
# define board
############################################################

width = 1.02 # board width
height = .87 # board height
x = 1 # x origin
y = 1 # y origin
zt = 0 # top z
zb = -0.06 # bottom z
w = .015 # wire width
rv = 0.016 # via radius
rp = 0.03 # pad radius
mask = .004 # solder mask size

pcb = PCB(x,y,width,height,mask)

IC1 = ATtiny44_SOICN('IC1\nt44')
pcb = IC1.add(pcb,x+.49,y+.56)

V1 = via(zb,zt,rv,rp,'V1')
pcb = V1.add(pcb,IC1.pad[14].x+.08,IC1.pad[14].y+.02)

pcb = wire(pcb,w,
   V1.pad[1],
   IC1.pad[14])

J1 = header_ISP('J1\nISP')
pcb = J1.add(pcb,IC1.x+.05,IC1.pad[7].y-.22,angle=90)

pcb = wire(pcb,w,
   IC1.pad[8],
   point(J1.pad[1].x,IC1.pad[8].y),
   J1.pad[1])

pcb = wire(pcb,w,
   IC1.pad[9],
   point(J1.pad[3].x,IC1.pad[9].y),
   J1.pad[3])
   
pcb = wire(pcb,w,
   IC1.pad[7],
   point(IC1.pad[7].x,J1.y+.02),
   point(IC1.pad[7].x+.04,J1.y-.02),
   point(J1.pad[4].x,J1.y-.02),
   J1.pad[4])
   
pcb = wire(pcb,w,
   IC1.pad[4],
   point(J1.pad[5].x,IC1.pad[4].y),
   J1.pad[5])

V2 = via(zb,zt,rv,rp,'V2')
pcb = V2.add(pcb,J1.pad[2].x+.075,J1.pad[2].y)

pcb = wire(pcb,w,
   V2.pad[1],
   J1.pad[2])

V3 = via(zb,zt,rv,rp,'V3')
pcb = V3.add(pcb,J1.pad[6].x-.075,J1.pad[6].y)

pcb = wire(pcb,w,
   V3.pad[1],
   J1.pad[6])

pcb = wire(pcb,w,
   V3.pad[2],
   V1.pad[2])

J2 = header_FTDI('J2 FTDI')
pcb = J2.add(pcb,x+width-.22,IC1.y-.0,angle=0)

pcb = wire(pcb,w,
   IC1.pad[13],
   point(IC1.pad[13].x+.105,IC1.pad[13].y),
   point(IC1.pad[13].x+.105,J2.pad[4].y),
   J2.pad[4])

pcb = wire(pcb,w,
   IC1.pad[12],
   point(IC1.pad[12].x+.07,IC1.pad[12].y),
   point(IC1.pad[12].x+.07,J2.pad[5].y+.04),
   point(IC1.pad[12].x+.11,J2.pad[5].y),
   J2.pad[5])

V4 = via(zb,zt,rv,rp,'V4')
pcb = V4.add(pcb,J2.pad[3].x+.1,J2.pad[3].y)

pcb = wire(pcb,w,
   V4.pad[1],
   J2.pad[3])

pcb = wire(pcb,w,
   V2.pad[2],
   V4.pad[2])

XTAL1 = XTAL_EFOBM('XTAL1\n20 MHz')
pcb = XTAL1.add(pcb,IC1.pad[4].x-.2,IC1.pad[13].y+.003,angle=-90)

pcb = wire(pcb,w,
   IC1.pad[2],
   point(XTAL1.x+.12,IC1.pad[2].y),
   point(XTAL1.x+.12,XTAL1.pad[1].y),
   XTAL1.pad[1])

pcb = wire(pcb,w,
   IC1.pad[3],
   XTAL1.pad[3])

V5 = via(zb,zt,rv,rp,'V5')
pcb = V5.add(pcb,XTAL1.x-.12,XTAL1.y)

pcb = wire(pcb,w,
   XTAL1.pad[2],
   V5.pad[1])

pcb = wire(pcb,w,
   V3.pad[2],
   V5.pad[2])

R1 = R_1206('R1\n10k');
pcb = R1.add(pcb,IC1.pad[1].x,IC1.pad[1].y+.1)

pcb = wire(pcb,w,
   R1.pad[1],
   IC1.pad[1])

pcb = wire(pcb,w,
   R1.pad[2],
   point(J1.pad[5].x,R1.y),
   J1.pad[5])

V6 = via(zb,zt,rv,rp,'V6')
pcb = V6.add(pcb,R1.pad[1].x-.08,R1.y)

pcb = wire(pcb,w,
   V6.pad[1],
   R1.pad[1])

pcb = wire(pcb,w,
   V4.pad[2],
   point(V4.x,V6.y,zb),
   V6.pad[2])

C1 = C_1206('C1\n1uF');
pcb = C1.add(pcb,IC1.pad[14].x,R1.y)

pcb = wire(pcb,w,
   J2.pad[1],
   C1.pad[2])

pcb = wire(pcb,w,
   C1.pad[2],
   V1.pad[1])

V7 = via(zb,zt,rv,rp,'V7')
pcb = V7.add(pcb,C1.pad[1].x-.025,C1.y-.06)

pcb = wire(pcb,w,
   V7.pad[1],
   C1.pad[1])

pcb = wire(pcb,w,
   V6.pad[2],
   point(V7.x,V6.y,zb),
   V7.pad[2])

############################################################
# select output
############################################################

outputs = {}
if (output == "top, labels, and exterior"):
   outputs["function"] = add(add(color(Tan,pcb.board),pcb.labels),
      color(White,pcb.exterior))
   outputs["layers"] = [zt]
elif (output == "top, labels, holes, and exterior"):
   outputs["function"] = add(add(color(Tan,pcb.board),pcb.labels),
      add(color(White,pcb.exterior),color(Blue,pcb.holes)))
   outputs["layers"] = [zt]
elif (output == "top, bottom, labels, and exterior"):
   outputs["function"] = add(add(color(Tan,pcb.board),pcb.labels),
      color(White,pcb.exterior))
   outputs["layers"] = [zb,zt]
elif (output == "top, bottom, labels, holes, and exterior"):
   outputs["function"] = add(add(color(Tan,pcb.board),pcb.labels),
      add(color(White,pcb.exterior),color(Blue,pcb.holes)))
   outputs["layers"] = [zb,zt]
elif (output == "top traces"):
   outputs["function"] = color(White,pcb.board)
   outputs["layers"] = [zt]
elif (output == "top traces and exterior"):
   outputs["function"] = color(White,add(pcb.board,pcb.exterior))
   outputs["layers"] = [zt]
elif (output == "bottom traces"):
   outputs["function"] = color(White,pcb.board)
   outputs["layers"] = [zb]
elif (output == "bottom traces reversed"):
   outputs["function"] = color(White,
      reflect_x(pcb.board,2*x+width))
   outputs["layers"] = [zb]
elif (output == "bottom traces reversed and exterior"):
   outputs["function"] = color(White,
      reflect_x(add(pcb.board,pcb.exterior),2*x+width))
   outputs["layers"] = [zb]
elif (output == "interior"):
   outputs["function"] = color(White,pcb.interior)
   outputs["layers"] = [zt]
elif (output == "exterior"):
   outputs["function"] = color(White,pcb.exterior)
   outputs["layers"] = [zt]
elif (output == "holes"):
   outputs["function"] = color(White,
      subtract(add(pcb.exterior,pcb.interior),pcb.holes))
   outputs["layers"] = [zb]
elif (output == "holes and interior"):
   outputs["function"] = color(White,
      subtract(pcb.interior,pcb.holes))
   outputs["layers"] = [zb]
elif (output == "solder mask"):
   outputs["function"] = color(White,pcb.mask)
   outputs["layers"] = [zt]
else:
   print("oops -- don't recognize output")

############################################################
# set limits and parameters
############################################################

border = 0.05
outputs["xmin"] = x-border # min x to render
outputs["xmax"] = x+width+border # max x to render
outputs["ymin"] = y-border # min y to render
outputs["ymax"] = y+height+border # max y to render
outputs["mm_per_unit"] = 25.4 # use inch units
outputs["type"] = "RGB" # use RGB color

############################################################
# send output
############################################################

json.dump(outputs,sys.stdout)