THE SPRK FACTORY

FREELANCE EMBEDDED ENGINEERING

Firmware, hardware & sparks of magic

I write the firmware that gets embedded products shipped, and I embed into your team to do it.

Antwerp, Belgium · remote, hybrid or on-site

▸ click the glowing things in the studio

▼

01 About the human

Hi, I'm Ivan Herrera Olivares, the one engineer behind The Sprk Factory.

I'm a freelance embedded engineer based in Antwerp, Belgium, working out of the studio above (yes, cat included). Companies bring me in to get embedded products shipped: I write the firmware and tame the radios, then help build the hardware around them.

I work remotely by default, but I'm on Central European time and a short flight from most of the continent. Hybrid works fine, and I'll come put hands on the hardware in your lab when a job calls for it.

I care about the unglamorous things that decide whether an embedded product actually ships: clean architecture, firmware you can debug at 2am, and documentation the next engineer won't curse.

  • I write things down as I go. Whoever picks up the code next isn't reverse-engineering my week.
  • Boring firmware is good firmware. I'd rather ship something predictable than something clever.
  • Point me at a goal and I'll run with it. You won't have to chase me for an update.
  • C / C++ / Rust on bare-metal & RTOS
  • BLE · Wi-Fi · LoRa · OTA pipelines
  • A bench full of scopes, probes & protoboards
  • Quality assurance department: one cat

// peer-reviewed Published research

Oh, and some of it ended up in journals. The trackers from IoSA, my Internet of Small Animals venture, show up in a handful of papers:

  1. Intra- and Interspecific Effects on Spatio-Temporal Behavior of Common Commensal Rodent Species

    Integrative Zoology · 2026 · Journal article

  2. Miniaturised Bluetooth Low Energy proximity loggers to study contacts among small rodents in agricultural settings

    PLOS ONE · 2025 · Journal article

  3. ProxLogs: Miniaturised proximity loggers for monitoring association behaviour in small animals

    Hystrix, the Italian Journal of Mammalogy · 2021 · Journal article

Full list on Google Scholar →

02 What I build

Firmware & RTOS development

Production firmware in C, C++ and Rust, on Cortex-M and RISC-V cores: STM32, Nordic's nRF52/53/54, ESP32, and custom private silicon. Bare-metal drivers, BSPs, and full RTOS applications on FreeRTOS or Zephyr, plus the bootloaders, power management and test harnesses that keep it honest.

  • STM32
  • nRF52/53/54
  • ESP32
  • RISC-V
  • Zephyr
  • FreeRTOS

IoT & connectivity

Devices that stay connected in the field: BLE, Wi-Fi, LoRaWAN and cellular, plus the cloud integration, fleet provisioning and OTA updates that won't brick a unit a thousand miles away.

  • BLE
  • LoRaWAN
  • MQTT
  • OTA / DFU
  • Security

Prototyping & consulting

Fast proof-of-concepts on dev boards, with the 3D printer in the corner doing the enclosures. Plus feasibility studies, architecture reviews and firmware audits when you need a second pair of eyes.

  • PoC sprints
  • 3D printing
  • Code audits
  • Architecture

03 Trusted by

// the teams and clients I've built firmware for

    04 Selected work

    // problem → process → result · client specifics kept vague where under NDA

    Smart bollard connectivity

    Problem
    Smart bollards deployed at one of the world's major ports needed a reliable way to receive firmware updates in the field, over the air.
    Process
    Added NB-IoT as an extra FOTA transport alongside the existing path, and stood up a proof-of-concept backend to drive the rollouts.
    Result
    A 200-device fleet updatable over NB-IoT, so nobody has to drive out to the quayside to do it.
    • NB-IoT
    • FOTA
    • PoC backend

    Silicon firmware

    Problem
    Production silicon needs firmware that proves the hardware and de-risks the path to volume.
    Process
    Firmware close to the metal, working shoulder-to-shoulder with the hardware team. (Details under NDA.)
    Result
    Shipping silicon with firmware I helped get there.
    • Bare-metal
    • Drivers
    • NDA

    Founding an embedded venture

    Problem
    Turning an idea into working embedded hardware and firmware, from a blank page.
    Process
    Owned the technical direction end to end: architecture, firmware and prototyping on the bench upstairs.
    Result
    500+ units shipped to customers across 12+ countries.
    • Architecture
    • Firmware
    • Hardware

    05 Kind words

    // 1-2 attributed quotes from people I've built things with

    Ivan dropped into our firmware team and was shipping useful work inside the first week. Clean code, clear comms, and we never had to hand-hold him.
    — Name Surname Engineering Lead · Company

    06 Start a project

    Got an idea that needs firmware, or firmware that needs rescuing?
    The kettle in the studio is always on.

    ivan.herreraolivares@gmail.com message me on LinkedIn
    LinkedIn ↗ GitHub ↗