PyPcb

Have you noticed how boring it is to draw PCB schematics?

1. Find each component in a list,
2. Place it somewhere in the drawing
3. Connect each of the hundreds of wires
4. Try to keep it all tidy (And fail at it)
5. Copy-Paste (Many, many times)

Although these are all important things to do on a PCB design, they should be postponed to the layout. Indeed, the only thing the layout editor uses from the schematic is the netlist.

To me, drawing schematics sound very much like programming with Ladder logic or Scratch: Fun and Educative, but too inefficient for real life.

Fortunately, I've had the chance to learn VHDL, and I found that describing hardware components with a programming language is great!

I've looked for other HDL targetting PCBs, but wasn't impressed by any of the existing projects and decided to try on creating my own.

Quick Start

from pcb import *

# Declare the components you are going to use
# Importing existing components from KiCad/Eagle/etc is in my TODO list ;)
class Led(Component):
    anode = WireAttribute()
    cathode = WireAttribute()

class Resistor(Component):
    A = WireAttribute()
    B = WireAttribute()

class Microcontroller(Component):
    vcc = WireAttribute()
    gnd = WireAttribute()
    pb1 = WireAttribute()
    pb2 = WireAttribute()
    pb3 = WireAttribute()

# Create a microcontroller.
microcontroller = Microcontroller()

# Plug the power to the microcontroller. `Power.GND` and `Power.VCC` are pre-defined nets for convenience.
microcontroller.vcc = Power.VCC
microcontroller.gnd = Power.GND


# Let's connect a few LEDs to the microcontroller ports!

# We can connect the pins after creation
led1 = Led("Led1")
r1 = Resistor("R1")
r1.A = Power.GND
r1.B = led1.anode
led1.cathode = microcontroller.pb1

# Or using named arguments during creation
led2 = Led("Led2", cathode=microcontroller.pb2)
r2 = Resistor("R2", A=Power.GND, B=led2.anode)

# This also works, but is hard to read
Led("Led3", anode=Resistor("R3", A=Power.GND).B, cathode=microcontroller.pb3)


# schematic is done! Print the circuit netlist
# This netlist is not in any standard format and is only for debugging.
microcontroller.print_netlist()

Project Status

This Project is only a quick'n'dirty Proof-Of-Concept.

It has no pratical use yet.

If I do find the time and willpower to continue working on it, the next steps are:

• Import component library from other tools
• Export netlist that can be parsed by other tools
• Support hierarchical components
• Support Numbered Buses: PB[8] instead of [PB0, PB1, PB2, etc]
• Support Named Buses: Serial1 instead of [GND, RX1, TX1]
• Support parametric components

Other tools to integrate to:

• KiCad
• Eagle
• Proteus
• Razen
• Spice
• ...?