kicad_firmware_generation
Christopher Besch • 20th February 2026

kicad_firmware_generation

Automatic Firmware Generation for Spaceflight Hardware based on Schematics

PLUTO: a Satellite

Credit: DLR

PCDU (Power Conditioning and Distribution Unit)

  • Between solar arrays, battery and subsystems
  • STM32 with firmware
    • Important job: TMTC
      Telemetry (i.e., current draw)
      Telecommand (i.e., power up/down specific subsystem)

PCDU Development

  • PCDUs for same satellite class do fundamentally same job
    but, e.g., different voltage outputs (e.g., 12V vs 3.3V)
  • Snippet based (electrical) design
    • Snippet: group of components with well-defined function (e.g., ADC)
    • Design new PCDU using existing snippets
  • Bottleneck: firmware development
    • Design goal: speed up firmware similar to electrical design
      → "Automatic Firmware Generation for Spaceflight Hardware
      based on Schematics"

KiCad Schematics

→ C++ Firmware
  • Currently: firmware engineer manually reads schematics

Challenges

  • How to get and understand hardware specification?
  • How to generate C++ firmware?
    • How to enrich data from schematics with other information?
      (e.g., OS abstractions)
  • How to make usable outside PCDU development?
    • What information do other use-cases require?

Contribution

Tooling Overview (1)

Tooling Overview (2)

Group

  • Collection of components
  • With set of Pins
  • Can be snippet (doesn't have to)

Group Netlist XML

  • Abstract view on hardware (challenge: right degree of abstraction)
  • Store Group connections
  • With Python library (parse and provide different perspectives)

Tool 1: kicad_group_netlister

  • Jobs:
    1. Group components
    2. Find connections
  • KiCad netlist → Group Netlist
    • Don't use schematics directly
    • KiCad-CLI creates Netlist
    • Circumvent tracing problem: Same behavior as KiCad

Group ID

ICA_EPS_Distribution/ADCS/ADC1/Snippet_ADC128S102 Schematic           Sheet Path Group Type        

Annotations (Group Type and Pin Name)

KiCad Sheet Hierarchy

Tooling Overview (2)

Tooling Overview (3)

Tool 2: code_gen

  • Read Group Netlist
    (with Python library)
  • Pass info to Jinja2 template
    → Project specificities in template
    → Support arbitrary language
    → Open-Source tooling

Jinja2 Template

→ Output

Tooling Overview (3)

Tooling Overview (4)

Tooling Overview (5)

Tool 3: netlist_to_csv

  • Example use-case: harness specification
    • Wiring between subsystems
  • Create spreadsheet showing
    • list of connectors
    • connector types
    • connector pinouts

Tooling Overview (5)

Tooling Overview (6)

Tooling Overview (7)

Tool 4: group_netlist_merger

  • Multiple PCBs with connectors
  • Use:
    1. Generate Group Netlist for each PCB
    2. Specify connectors to connect → group_netlist_merger
    3. Use combined Group Netlist
      e.g., firmware for combined hardware

Tool 4: group_netlist_merger

  • Multiple PCBs with connectors
  • Use:
    1. Generate Group Netlist for each PCB
    2. Specify connectors to connect → group_netlist_merger
    3. Use combined Group Netlist
      e.g., firmware for combined hardware

Integration in PCDU Design Process

  • Generate hardware definition C++ header and LCL driver firmware
    → Found error in hardware
  • Generate spreadsheet harness specification

Quantitative Evaluation

  • Lines of code:
    Group Netlist library 414
    kicad_group_netlister 426
    code_gen 118
    netlist_to_csv 169
    group_netlist merger 185
    Snippet based design analysis 65
  • Asserts: 160
  • PLUTO's PCDU: 1.7s (sum of all tools; component count: 2494)
  • Synthetic benchmark: 120 tests
 
  1. KiCad Netlist
    → solve tracing problem
  2. Intermediate format
    → unlocks use-cases
  3. Jinja2 → Open-Source
github.com/DLR-RY/kicad_firmware_generation

Appendix

Development Process

State 1

State 2

State 3

  • Rapid iteration: great
    ← requirements unknown
  • Striving for simplicity: great