Embedded Firmware Engineer - Hybrid, STM32 & CAN

ERNI; Valencia; Hybrid; EUR 42,000 - 65,000; Full time

Benefits offered by this job

Private health and travel insurance

Gym discounts

23 vacation days

Job summary

ERNI is seeking an Embedded Firmware Engineer in Valencia to design, develop, and maintain bare-metal firmware for ARM Cortex-M devices. You will work mainly with C/C++ on STM32 or equivalent MCUs, implementing CAN, Modbus, UART, I2C, and SPI interfaces while collaborating with electronics designers.

You’ll read schematics, use test equipment, and contribute to hardware/software decisions. The role requires at least 3 years of embedded firmware experience and English fluency; German is a plus.

Qualifications

• Bachelor’s degree in Software/Electrical Engineering or related field.
• At least 3 years of professional embedded firmware development experience.
• Strong C skills and modern C++ experience (C++14/17) for resource-constrained targets.
• Hands-on bare-metal experience with ARM Cortex-M, including startup code, linker scripts, interrupt and DMA handling, low-power modes and register-level peripheral setup.

Responsibilities

• Develop, test and maintain bare-metal firmware in C and C++ for ARM Cortex-M microcontrollers, primarily STM32 and comparable families.
• Implement and debug communication stacks and drivers for CAN/CANopen, Modbus RTU and TCP, UART, RS-232/RS-485, I²C and SPI.
• Write low-level drivers for ADCs, DACs, timers, DMA, PWM and interrupt-driven peripherals used to interface with sensors and actuators.
• Bring up new boards with hardware engineers: review schematics, take measurements and investigate issues where hardware and software do not behave as expected.
• Contribute to electronics design through component selection, schematic reviews and design-for-test input.
• Create unit and hardware-in-the-loop tests, document your work and support verification against EMC and safety standards.
• Investigate field issues with service and production teams, and maintain firmware for products already in the market.
• Collaborate with physicists, mechanical, electronics and software engineers, including colleagues at international sites.

Skills

Embedded C/C++

ARM Cortex-M

CAN/Modbus/UART/I2C/SPI

Git

Schematic reading

Hardware/software interfacing

English fluent

Lab equipment

Education

Bachelor’s degree in Software/Electrical Engineering or related field

Tools

STM32CubeIDE/CubeMX

HAL/LL drivers

Oscilloscopes/Logic analyzers

Job description

ERNI is seeking an Embedded Firmware Engineer in Valencia to design, develop, and maintain bare-metal firmware for ARM Cortex-M devices. You will work mainly with C/C++ on STM32 or equivalent MCUs, implementing CAN, Modbus, UART, I2C, and SPI interfaces while collaborating with electronics designers.

You’ll read schematics, use test equipment, and contribute to hardware/software decisions. The role requires at least 3 years of embedded firmware experience and English fluency; German is a plus.