10/24/2026 updated
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Embedded HW & Firmware Engineer | STM32, CANopen, LoRaWAN, Altium, KiCad | EN 50155
Dubrovnik, Croatia
Only remote
Master of Electrical Engineering (mag. ing. el.), Zagreb University of Applied SciencesAbout me
Embedded engineer who takes a product from schematic to series production: hardware, PCB layout and STM32 firmware. Rail (EN 50155), mining, defence and agri-IoT experience. Remote from Dubrovnik, Croatia, CET; clear documentation and weekly updates.
Altium DesignerBattery ManagementBluetooth Low Energy (Bluetooth)C++ (Programming Language)CAN BusPrinted Circuit BoardElectrical System DesignEmbedded CEmbedded SystemsEmbedded SoftwareFirmwareFreeRTOSHardware DesignModbusRailway Engineering
I design electronics end to end: schematic, PCB layout and the embedded firmware that runs on it. My boards run in railway vehicles, mining machines, military vehicles and agricultural sensor networks, so I design for the field, not just the lab.
What I can take on:
- Complete boards from requirements to production files: schematic, 2-6 layer PCB layout, BOM, Gerbers, pick-and-place, 3D STEP (Altium Designer, KiCad)
- STM32 firmware in C/C++ with FreeRTOS or Zephyr: drivers, CAN / SAE J1939, RS485 / Modbus, UART, SPI, I2C, bootloaders, low-power design
- Power electronics: 200-400 V DC/DC converters, BLDC motor control, proportional valve drives, battery management (BMS)
- Wireless IoT devices: LoRaWAN, LTE-M / NB-IoT, Bluetooth LE, UWB, ESP32, nRF52
- EN 50155 railway electronics, EMC-aware layout, hardware bring-up, debugging and design reviews
- CANopen (master and slave on one unit) and Modbus RTU/TCP
- Design review and compliance check before CE/EMC lab tests (EN 60730, EN 50155), written report with prioritized fixes
- Selected work:
- 5-channel closed-loop proportional valve controller for rail vehicles (EN 50155, STM32G4), in series production
- 200-400 V to 2 x 24 V / 42 A DC/DC supply for an electric mining rig, built in a production batch
- High-voltage power distribution board with J1939 diagnostics and CAN bootloader
- LoRaWAN soil sensor node, six hardware revisions, 2 uA sleep current (hardware + firmware)
- RS485-to-LTE-M gateway firmware with AES-encrypted upload (STM32L4, FreeRTOS)
- Thermal AI camera node: Raspberry Pi 5 + STM32 supervisor
- Battery and supercapacitor characterisation (impedance spectroscopy) for production test equipment
- How I work: you receive the source files, not just outputs: schematic PDF, layout project, BOM, firmware repository with README and a bring-up report. Weekly progress notes, open questions raised early.
- Master of Electrical Engineering. Languages: English (fluent), German (conversational), Croatian (native). Based in Dubrovnik, Croatia, working remotely in CET; on-site visits in DACH possible.
- Deutsch: Embedded-Hardware- und Firmware-Entwicklung, Leiterplattenentwicklung (Altium, KiCad), STM32-Firmware in C/C++, Leistungselektronik und Bahnelektronik nach EN 50155. Remote aus Kroatien, MEZ.
Experience
Professional experience5 - 10 years
Freelancer since2025
Languages
GermanGoodEnglishFluentCroatianNative speaker
Project history
Full product lifecycle for industrial and rail electronics, from requirements and PCB architecture to schematic, layout and firmware, on STM32 and NXP with Zephyr and FreeRTOS.
- Railway HVAC BLDC motor controller to EN 50155
- 5-channel closed-loop proportional valve driver to EN 50155 (STM32G491), in series production
- Industrial gateway with galvanically isolated Ethernet, CAN, RS485, RS232 and 1-Wire
Product development for industrial and IoT clients, alongside employment.
- LoRaWAN soil sensor node for agriculture: RS485/Modbus probes, 2 uA sleep, six hardware revisions and firmware releases 51 to 91 (hardware + firmware)
- RS485-to-LTE-M gateway firmware: SMS relay, AES-encrypted telegram upload, bootloader and PC configurator (STM32L4, FreeRTOS)
- Thermal AI camera node: Raspberry Pi 5 inference with an STM32L452 power and watchdog supervisor
- Solar IoT driver for remote actuators: one PCB, STM32WLE5 LoRaWAN and nRF52840 BLE variants
- AI + UWB smart flashlight carrier board with ESP32 sensor fusion and LED driver
Research and test-equipment development for EV batteries and supercapacitors, in cooperation with JKU Linz.
- Factory calibration methods for electrochemical impedance spectroscopy (EIS) equipment on the production line
- Battery digital twin built from EIS data in QSPICE, with test-automation plugins for hardware-in-the-loop validation
- Measurement standards for second-life battery use; results presented at EU project meetings and published in a peer-reviewed paper