Carl Henriksson

Embedded Firmware & Validation Engineer

cv@carlhenriksson.comgithub.com/martial-cclinkedin.com/in/carl-h-henrikssonOslo, Norway

Profile

Embedded test and firmware engineer focused on building secure, reliable systems through measurement and repeatable validation. Upstream contributor to the OpenBSD if_rge network driver (merged October 2025). Production work spans embedded firmware (Zephyr/ZMK on nRF52840), Python measurement pipelines, and CI/release automation, owned end to end. Open to embedded and systems roles.

Technical Skills

C · Python · Embedded firmware · Test automation · Zephyr/ZMK · nRF52840 · SPI · BLE · USB HID · GitHub Actions · Linux · OpenBSD · UART debugging · Firmware flashing · Signal analysis · Measurement pipelines · CI/release automation

Key Evidence

  • Upstream contribution to the OpenBSD if_rge network driver, merged October 2025 — validated under 48 hours of continuous load before submission.
  • Production embedded firmware on nRF52840: board support, SPI sensor integration, BLE/USB HID, battery reporting, and CI-generated releases.
  • Sensor and transport validation across USB and Bluetooth, from polling behaviour to encoder correctness.
  • Python measurement and signal-analysis pipelines for audio characterization, in active daily use.
  • Signal-level hardware debugging: UART inspection, chip flashing via programmers, firmware diagnosis from binary and assembly images.

Experience

Independent Embedded Firmware, Test Software & Infrastructure Engineering

Embedded firmware, Python measurement tooling, validation, operations, and release ownership for production systems

  • Sole owner of architecture, implementation, validation, release, and long-term maintenance for every project listed below.
  • Ship production embedded firmware (Zephyr/ZMK on nRF52840) through a repeatable, CI-generated UF2 release pipeline.
  • Build validation workflows and Python measurement tooling for hardware and audio characterization.
  • Debug embedded hardware at the signal level and operate deployed infrastructure with documented invariants.

Senior Cocktail Bartender & License Co-holder — Himkok

Regulated high-precision service environment · compliance, training, and process ownership

Regulatory compliance · Staff training · Process control · Distillation · Communication

  • Himkok reached its peak of #11 on the World's 50 Best Bars list during this period.
  • Co-holder of the alcohol license (stedfortreder for skjenkebevilling) — legal accountability in a regulated domain with regular compliance controls.
  • Trained staff and operated in high-volume, high-precision service environments where coordination, communication, and error handling were critical.
  • Contributed to method development and controlled production processes, including in-house distillation.

Independent Consultant — Hospitality & Bar Operations

Prominent Norwegian fine dining and bar institutions · ENK

Operations · Product · Staff training · Communication

  • Worked across service, team leadership, menu development, and concept definition for established Norwegian hospitality venues.

Selected Highlights

WeekFirst

Production collaborative habit-tracking platform with active users. Built a real-time Cloudflare Pages/Durable Objects application with WebSocket sync, REST fallback, offline operation, local persistence, and multi-device replication.

weekfirst.com

MOTR

Production nRF52840 firmware and sensor characterization. Developed aftermarket firmware for the Polarity Works ROTR platform: board support, MA730 SPI magnetic encoder driver, BLE and USB HID, battery reporting, RGB, build automation, and CI-generated UF2 releases. Validation work included polling interval tuning, absolute encoder delta handling, wrap-around correctness verification, and transport validation over USB and Bluetooth.

carlhenriksson.com/motr-firmware

Infrastructure

Router-centric infrastructure and security architecture, in production. OpenBSD as Layer-3 authority, isolated control planes, default-deny routing, management separation, and documented operational invariants.

carlhenriksson.com/openbsd-contribution

OpenBSD

Upstream network driver contribution (if_rge, merged October 2025). Hit an unrecognised Realtek hardware revision while deploying a segmented OpenBSD architecture; implemented driver support, validated stability under 48 hours of continuous load testing, and contributed the fix upstream.

carlhenriksson.com/openbsd-contribution

AutoDJ

Audio signal characterization and measurement pipeline, in active daily use. Python backend for per-track measurement of BPM, LUFS, and loudness range; live filtering against user-defined targets with dynamic constraint propagation; and playlist export. Includes ingestion, validation, search, API contracts, and operational configuration.

Further Projects

Keep

Distributed state synchronization runtime. Abstracts persistence, reconnection, offline recovery, operation replay, multi-client sync, QR sharing, and storage backends behind a minimal app interface.

SBFW

Deterministic static publishing framework. Implements metadata, manifests, service workers, sitemaps, security artifacts, validation, monolithic output, and deployable static builds.

carlhenriksson.com/the-static-builder

Folio

Content publishing engine. Provides discovery, frontmatter parsing, wikilinks, transclusion, component injection, design tokens, and deterministic publishing integration.

carlhenriksson.com/the-static-builder

Education

Self-directed technical development

Embedded systems and software engineering, with production work across embedded C, Python measurement tooling, network systems, firmware debugging, release automation, and repeatable validation of hardware/software systems.