Automating Firmware Generation from Schematics for Microcontroller based Designs

Christopher Besch, Janis S. Häseker, Hassan Nassar, Norbert Toth, Jörg Henkel • 2nd October 2026

Automating Firmware Generation from Schematics for Microcontroller based Designs

PLUTO's PCDU (Power Conditioning and Distribution Unit)

A Snippet

A Group Netlist

To tackle this problem we got together with the Chair for Embedded Systems at the Karlsruhe Institute for Technology and together introduce the Group Netlist. The Group Netlist is an abstract and tool agnostic representation of the hardware.
We group multiple components fulfilling a well defined function into Groups. The schematics on the left, for example, shows one such Group. You can find this ADC in the simplified Group Netlist on the right. As you can see, the Group Netlist represents what Groups there are and how they interconnect. Therefore, the Group Netlist contains exactly the information needed to write firmware.

kicad_firmware_generation

github.com/DLR-RY/kicad_firmware_generation

To validate our approach, we implemented kicad_firmware_generation, a reference implementation for KiCad. It starts by generating an XML Group Netlist out of the hardware's KiCad netlist. To understand what Groups there are, each snippet's external pin needs a simple annotation. Afterwards our tooling generates firmware from the Group Netlist and Jinja2 templates.
The workflow is entirely deterministic and thus fit for continuous integration. Where previously a cumbersome process bridged hardware and firmware development, our approach continuously runs and ensures that hardware and software are consistent.
Once we introduced our tooling into the PCDU development it found a fault in the PCDU's electrical design! Two control pins for a power switch were swapped. No one spotted this fault before because the power switch and the microcontroller are actually on different boards, bridged through a large connector. One has to trace the circuit through five pages of schematics split across two projects to find the fault. Our tooling caught the fault as a by-product of firmware generation.

Systematic Fault Injection

Inject faults into PCDU schematics:
swap labels, delete cables
8885 unique faults
Result: detected up to 75% of otherwise not found Group Pin swaps

Synthetic Benchmark

Group Netlist

kicad_firmware_generation

github.com/DLR-RY/kicad_firmware_generation

Time Sensitive Network (TSN)

Networking inside Spacecraft

Real-time: worst-case delay, jitter
Previously: specialized point-to-point connections
→ heavy, costly, power inefficient
Can we use Ethernet & IP?

Transport Layer

UDP

Unreliable service
(e.g., packets might be dropped)
Simple (3 pages in RFC 768)

TCP

Reliable service using
Automatic Repeat Request (ARQ)
Complex (98 pages in RFC 9293)

Time Sensitive Networking (TSN)

Standardised under IEEE 802.1Q
Reliability at link layer: never drop a packet → no need for TCP
Accurate time-stamps based on PTP (Precision Time Protocol)
Hard timing guarantees

Redundant TSN Ring for Space

Single failure criterion
Goal: Demonstrator, Validation

Redundant TSN Ring for Space

Single failure criterion
Goal: Demonstrator, Validation

TSN VPN

Link remote locations with VPN for best-effort and real-time traffic
Problem: public Internet without real-time guarantees
Idea: separate real-time network into source and drain sections
synthetic delay to hide jitter, hidden by faked PTP

TSN VPN Development

Goal: Implementation, Validation
Source and drain at same physical location
Proxy in Karlsruhe for real Internet delay
Measure latency with 1PPS

Completed Steps

6-module ring demonstrator setup in Karlsruhe
Hardware procurement at DLR
PTP Test with two devices
Investigation into Zephyr and Device Trees
Research into Linux networking stack

Completed Artefacts

State of the art report
DLR Proposal for TSN VPN development setup
Article on Linux userspace networking
Article on UDP broadcast relay over Wireguard
Article on Zephyr LCD driver development
Article on Zephyr's IWDG watchdog driver
Zephyr contribution #108622

Next Steps

Setup 1PPS Measurement
Setup Redundant Ring Networking
Simulate TSN Ring Traffic
Simulate TSN Ring fault scenario
Design & Setup TSN VPN Setup
Implement TSN VPN
Test TSN VPN