The SKiDL Python package lets you compactly describe the interconnection of electronic circuits and components. The resulting Python program performs electrical rules checking for common mistakes and outputs a netlist that serves as input to a PCB layout tool.
- Free software: MIT license
- Documentation: http://devbisme.github.io/skidl
- User Forum: https://github.com/devbisme/skidl/discussions
- Has a powerful, flexible syntax (because it is Python).
- Permits compact descriptions of electronic circuits (think about not tracing signals through a multi-page schematic).
- Allows textual descriptions of electronic circuits (think about using
diff
and git for circuits). - Performs electrical rules checking (ERC) for common mistakes (e.g., unconnected device I/O pins).
- Supports linear / hierarchical / mixed descriptions of electronic designs.
- Fosters design reuse (think about using PyPi and Github to distribute electronic designs).
- Makes possible the creation of smart circuit modules whose behavior / structure are changed parametrically (think about filters whose component values are automatically adjusted based on your desired cutoff frequency).
- Can work with any ECAD tool (only two methods are needed: one for reading the part libraries and another for outputing the correct netlist format).
- Can perform SPICE simulations (Python 3 only).
- Takes advantage of all the benefits of the Python ecosystem (because it is Python).
As a very simple example (see more in the blog), the SKiDL program below describes a two-input AND gate built from discrete transistors:
from skidl import *
# Create part templates.
q = Part("Device", "Q_PNP_CBE", dest=TEMPLATE)
r = Part("Device", "R", dest=TEMPLATE)
# Create nets.
gnd, vcc = Net("GND"), Net("VCC")
a, b, a_and_b = Net("A"), Net("B"), Net("A_AND_B")
# Instantiate parts.
gndt = Part("power", "GND") # Ground terminal.
vcct = Part("power", "VCC") # Power terminal.
q1, q2 = q(2) # Two transistors.
r1, r2, r3, r4, r5 = r(5, value="10K") # Five 10K resistors.
# Make connections between parts.
a & r1 & q1["B C"] & r4 & q2["B C"] & a_and_b & r5 & gnd
b & r2 & q1["B"]
q1["C"] & r3 & gnd
vcc += q1["E"], q2["E"], vcct
gnd += gndt
generate_netlist(tool=KICAD8) # Create KICAD version 8 netlist.
And this is the output that can be fed to a program like KiCad's PCBNEW
to
create the physical PCB:
(export (version D) (design (source "/home/devb/projects/KiCad/tools/skidl/tests/examples/svg/simple_and_gate.py") (date "07/19/2024 05:54 AM") (tool "SKiDL (1.2.2)")) (components (comp (ref #PWR1) (value GND) (footprint ) (fields (field (name F0) #PWR) (field (name F1) GND)) (libsource (lib power) (part GND)) (sheetpath (names /top/18388231966295430075) (tstamps /top/18388231966295430075))) (comp (ref #PWR2) (value VCC) (footprint ) (fields (field (name F0) #PWR) (field (name F1) VCC)) (libsource (lib power) (part VCC)) (sheetpath (names /top/12673122245445984714) (tstamps /top/12673122245445984714))) (comp (ref Q1) (value Q_PNP_CBE) (footprint ) (fields (field (name F0) Q) (field (name F1) Q_PNP_CBE)) (libsource (lib Device) (part Q_PNP_CBE)) (sheetpath (names /top/5884947020177711792) (tstamps /top/5884947020177711792))) (comp (ref Q2) (value Q_PNP_CBE) (footprint ) (fields (field (name F0) Q) (field (name F1) Q_PNP_CBE)) (libsource (lib Device) (part Q_PNP_CBE)) (sheetpath (names /top/12871193304116279102) (tstamps /top/12871193304116279102))) (comp (ref R1) (value 10K) (footprint ) (fields (field (name F0) R) (field (name F1) R)) (libsource (lib Device) (part R)) (sheetpath (names /top/17200003438453088695) (tstamps /top/17200003438453088695))) (comp (ref R2) (value 10K) (footprint ) (fields (field (name F0) R) (field (name F1) R)) (libsource (lib Device) (part R)) (sheetpath (names /top/12314015795656540138) (tstamps /top/12314015795656540138))) (comp (ref R3) (value 10K) (footprint ) (fields (field (name F0) R) (field (name F1) R)) (libsource (lib Device) (part R)) (sheetpath (names /top/11448722674936198910) (tstamps /top/11448722674936198910))) (comp (ref R4) (value 10K) (footprint ) (fields (field (name F0) R) (field (name F1) R)) (libsource (lib Device) (part R)) (sheetpath (names /top/2224275500810828611) (tstamps /top/2224275500810828611))) (comp (ref R5) (value 10K) (footprint ) (fields (field (name F0) R) (field (name F1) R)) (libsource (lib Device) (part R)) (sheetpath (names /top/3631169005149914336) (tstamps /top/3631169005149914336)))) (nets (net (code 1) (name A) (node (ref R1) (pin 1))) (net (code 2) (name A_AND_B) (node (ref Q2) (pin 1)) (node (ref R5) (pin 1))) (net (code 3) (name B) (node (ref R2) (pin 1))) (net (code 4) (name GND) (node (ref #PWR1) (pin 1)) (node (ref R3) (pin 2)) (node (ref R5) (pin 2))) (net (code 5) (name N$1) (node (ref Q1) (pin 2)) (node (ref R1) (pin 2)) (node (ref R2) (pin 2))) (net (code 6) (name N$2) (node (ref Q1) (pin 1)) (node (ref R3) (pin 1)) (node (ref R4) (pin 1))) (net (code 7) (name N$3) (node (ref Q2) (pin 2)) (node (ref R4) (pin 2))) (net (code 8) (name VCC) (node (ref #PWR2) (pin 1)) (node (ref Q1) (pin 3)) (node (ref Q2) (pin 3)))) )