Embedded Firmware Development Services from Bare-Metal to Embedded Linux
Embedded firmware development services for teams that already have a board, or a hardware partner designing one, and need the software on it done right. Architecture, drivers, BLE and Wi-Fi, OTA with rollback, low-power behavior and bring-up on the first prototypes, from senior engineers led by a founder who designs hardware and teaches embedded Linux, STM32 and ESP32.
What embedded firmware development services cover
Firmware is the software that lives on the device: it configures the microcontroller or SoC, talks to every sensor, radio and peripheral on the board, manages power, and keeps running for years without a reset. Embedded firmware development services, as we run them, cover that whole layer: the platform decision (bare-metal, an RTOS or embedded Linux), drivers, connectivity over BLE, Wi-Fi or LTE-M, over-the-air updates with rollback, secure boot, the low-power state machine, bring-up on the first boards, test and continuous integration, and documentation your next engineer can pick up.
This page is for teams that already have the hardware side covered: a board designed in-house, a hardware partner mid-way through layout, or a product in the field whose firmware needs a feature, a port or a rescue. If you want the whole electronics product from one team, that is our embedded hardware design and electronics development service; if the board itself is still open, start with PCB design.
Which firmware architecture fits the device
The first decision in a firmware project is what the code runs on top of, and it is the hardest one to reverse. We make it against the product's constraints, in roughly this order: power budget, radios, compute and memory, security, supply chain and certification path. The evaluation board you prototyped on is not a constraint.
- Bare-metal C or C++ on a small microcontroller when the job is well defined and the power budget is measured in microamps: a sensor node, a motor controller, a device that sleeps most of its life. Simplest to reason about and cheapest to test.
- An RTOS, usually Zephyr or FreeRTOS, when the device juggles a radio stack, several sensors, a display and a connectivity state machine at once. The scheduler buys structure; the price is a build system and conventions that have to be right on day one.
- Embedded Linux on an i.MX, Rockchip or Allwinner class SoC when the product runs inference, audio, video or a camera. It brings a board support package, a Yocto or Buildroot build, secure boot and a real update mechanism, and it needs engineers who have set those up before.
If the microcontroller is not chosen yet, the free MCU Selector asks five questions and shows its scoring, and ESP32 vs STM32 vs Arduino for production explains why the right chip for a prototype is rarely the right chip for a product. If it is chosen, we work with what you have; STM32, ESP32, Nordic nRF52 and nRF54, RP2040 and RP2350, NXP and Microchip PIC32 are all in regular use here.
What we build on the board
Connectivity: BLE, Wi-Fi and LTE-M
Connectivity is part of the architecture, not a feature bolted on at the end: for BLE, a command protocol with a version number from the first byte, so the phone app and the device can evolve separately; for Wi-Fi, provisioning that survives a real router and a mistyped password; for LTE-M, a modem state machine that rides out a weak signal without draining the battery. When the device reports to a server, we design both sides together; the cloud and IoT back end page covers device identity, telemetry and fleet management.
OTA updates with rollback, and secure boot
A field bug should be an update you push, not a product you recall, so over-the-air updates go into the first build rather than the last: signed images, a bootloader that verifies before it jumps, A/B slots so a failed update falls back to the version that worked, and a staged rollout so a bad image reaches ten devices before it reaches ten thousand. Secure boot belongs to the same design, because an update path that accepts any image is an attack path. The full pattern is in OTA firmware updates: architecture, security and safe rollback.
Low-power firmware
Battery life is decided by how the firmware sleeps, not by which cell you chose. A device that wakes for a few milliseconds a minute and sleeps at microamps otherwise lives for years; the same hardware with a polling loop lives for days. We design the power state machine first, measure it on the real board with a meter in the supply line, and keep that measurement in the test plan so a later commit cannot quietly double the sleep current. The free Battery Life Calculator turns duty cycle and sleep current into a runtime estimate, and reducing power consumption in battery devices lists the techniques in the order we apply them.
Bring-up on the first boards
Bring-up is its own phase, and a firmware engineer with a scope on the bench is where a prototype starts working: power rails and clocks verified, each peripheral proven in isolation, a board test firmware your production line can reuse, and a written list of every hardware issue found, ranked by what it costs to fix before the next spin. When the board is yours or your partner's, we ask for the schematic, the layout and a few units, and we join your design reviews so firmware constraints reach the layout before it goes to the fab.
Test, CI and handover
Firmware without tests becomes a liability the day its author leaves. Our standard is unit tests for the logic that can run on the host, a hardware-in-the-loop rig for the parts that cannot, continuous integration that builds every commit for every target and runs static analysis, and a release process that produces a signed, versioned image with a changelog. Handover is written for the engineer who comes after us: an architecture document, a build-from-clean guide and the decisions behind the code, so your next hire is productive in a week rather than a quarter.
What you receive from a firmware development engagement
- Firmware sources in your repository, with the build system, toolchain versions and CI configuration.
- An architecture document: the platform decision and its reasoning, the module map, the memory and power budgets, and the update design.
- Drivers for every peripheral, behind a boundary that lets you swap a part that goes on allocation without rewriting the product, and the OTA and secure boot design with a tested rollback path.
- A test plan and the rig to run it: host unit tests, hardware-in-the-loop tests and power measurements.
- A bring-up report and a production test firmware your contract manufacturer can run on the line.
- A handover guide written for the next engineer, and a handover session with your team.
How a firmware development engagement is priced
Everything is priced in engineering hours; you get a written quote with phases before any work starts. For calibration, from delivered work with client names removed: a wireless alert-light prototype, hardware and firmware together, was about 85 engineering hours; firmware and system integration for an embedded-Linux audio device with on-device inference and over-the-air updates was about 120. Most projects we quote total between 40 and 250 engineering hours; a driver or a feature on an existing codebase sits at the bottom of that band, and a new embedded Linux platform with its own board support package can sit above it. For a planning number, run the scope through the free project cost estimator or the AI estimator on the homepage.
Where we do firmware development work
We are based in Silicon Valley and work with teams across the United States, mostly remotely; how a nationwide engagement runs has the detail. Firmware suits remote work better than any other hardware discipline: the code lives in your repository, reviews and bring-up sessions run on video with the board on the bench and a camera on it, and prototypes ship by carrier when we need them here. We keep Pacific business hours, which cover the Eastern afternoon in full; in-person days in the Bay Area are by arrangement.
How a firmware development engagement starts
With a free 30-minute call with a senior engineer: bring the schematic, the chip you are leaning toward, or the bug that has eaten a month. A mutual NDA is signed before any technical detail is exchanged, you keep 100% of the IP, and inteRFace R&D never takes equity. The first paid step is bounded and quoted in writing: a firmware architecture review for a new product, or a codebase review for an existing one, delivered as a document with the risks ranked, the platform recommendation and a quote with phases for the work that follows. You can stop there and keep the document.
Choosing a firmware development company? The quickest way to find out whether we are the right one is the free call: book a time. If you would rather start with a decision, run your product through the free MCU Selector and bring the result.
Frequently Asked Questions
What do embedded firmware development services include?
The software layer on the device, end to end: the platform decision (bare-metal, RTOS or embedded Linux), drivers for every peripheral, connectivity over BLE, Wi-Fi or LTE-M, over-the-air updates with rollback and secure boot, the low-power state machine, bring-up on the first boards, a test rig with continuous integration, and documentation written for the engineer who comes after us. The engagement runs on its own, on your hardware, or alongside your hardware team.
Can you write firmware for a board someone else designed?
Yes; that is exactly the engagement this page describes. We need the schematic, the layout, the bill of materials, any existing code and a few boards on the bench; from there a short architecture or codebase review tells you what is solid, what is risky and what it would take. We do not need to redesign the electronics to write good firmware for them, and when a hardware change would genuinely help, we say so in writing.
Bare-metal, RTOS or embedded Linux: how do you decide?
By the product's constraints, in order: power budget, radios, compute and memory, security, supply chain and certification path. A device that sleeps most of its life and does one job is usually bare-metal. A device juggling a radio stack, sensors and a display is usually an RTOS such as Zephyr or FreeRTOS. A device running inference, audio, video or a camera is embedded Linux. We write the reasoning down so the choice can be defended to an investor or a new hire.
How much does embedded firmware development cost?
It is priced in engineering hours, and you get a written quote with phases before any work starts. For calibration from delivered work: a wireless alert-light prototype, hardware and firmware together, was about 85 engineering hours; firmware and system integration for an embedded-Linux audio device with on-device inference and OTA was about 120. Most projects we quote total 40 to 250 engineering hours. The free cost estimator at interfacernd.com/tools/cost-estimator gives you a planning range in minutes.
Do you work with teams outside the Bay Area?
Yes. We are based in Silicon Valley and work with teams across the United States, mostly remotely. Firmware suits that well: the code lives in your repository, design reviews and bring-up sessions run on video with the board on the bench and a camera on it, and prototypes ship by carrier when we need them here. We keep Pacific business hours, Monday to Friday, which cover the Eastern afternoon in full. In-person days in the Bay Area are by arrangement.
Who owns the firmware, and can we use our own repository and toolchain?
You own all of it: sources, build system, test rig, documents and project data, 100% of the IP, and we never take equity. We prefer to work inside your repository, your issue tracker and your review process so nothing leaves your control, and we run our own only when you do not have one yet. A mutual NDA is signed before any technical detail is exchanged.
Ready to talk specifics?
A 30-minute call with a senior engineer beats three rounds of email. Tell us what you're building.