C development services
We build and improve embedded firmware and native interfaces for teams developing hardware products. Our C development services cover reproducible builds, host-based tests and validation on the target device, with ownership of memory and timing behaviour.
01Capabilities
C programming at the hardware and interface boundary
We use C programming where the target hardware, supplier libraries or native interface make it a deliberate fit. We assess C++ against the same toolchain and memory requirements.
- Firmware
Microcontroller firmware and peripheral drivers
We develop firmware, peripheral drivers, board bring-up code and bootloaders within the part's memory limits and supplier software kit. This is the device-level software in hardware such as EV chargers and utility metering equipment.
- Protocol
Protocol parsers and long-running daemons
We build protocol libraries and background services around explicit buffer boundaries. Memory footprint and timing are design requirements that we verify, especially where code receives untrusted network input.
- Bridge
Native interfaces for existing applications
We write a small C interface so a higher-level application can call a performance-critical native component or a supplier library delivered as a header and compiled archive. Our integration work keeps that boundary testable and the application in its existing language.
- Inherited
Repeatable builds for inherited firmware
We make established codebases ready for continued development through a reproducible build, a test harness and an agreed warning policy. This modernization addresses conditional compilation and tool dependencies while preserving the firmware behaviour the product relies on.
02Fit
Which approach fits your device and codebase?
The target, tool support and existing code determine where C belongs. We compare the language choice with the smaller interventions that can support your next release.
| Your situation | What we recommend |
|---|---|
| Bare metal or a small real-time system, kilobytes of memory, and a vendor kit written in C | Use CBuild around the supplier kit, supported compiler and available memory. Check timing and memory use on the actual target. |
| A native component that benefits from C++ libraries and resource management, with suitable compiler support | Consider C++C++ can simplify resource ownership and reuse existing libraries. It also runs on small hardware; the available features and their resource costs need checking against the part. |
| A new, self-contained part on a well-supported chip, where a memory bug would be the worst outcome | Consider RustAssess Rust for a bounded component where memory safety matters. Confirm compiler, library and peripheral support for the specific chip before choosing it. |
| Business logic, a screen for someone to use, and a database behind it | A higher-level stackJava, Python or Django fit the application layer. Keep a C interface where that application needs to reach the device or a native library. |
| Firmware that already works and already ships | Test and automatePut regression tests around the logic and automate the build. Use those checks to support targeted changes while retaining working firmware. |
| You need C only to reach one supplier library from a larger application | Keep a small C interfaceTest the supplier boundary as a separate layer. Keep application features in the language your team maintains. |
Scope
We own the C build, memory and timing behaviour, and the interface to the surrounding software. Our delivery operates under ISO 27001:2022 certified information-security management and ISO 9001:2015 certified quality management. unicrew has built software since 2012 and has 100+ senior in-house engineers across six countries.
03Delivery
From a reproducible build to validation on the device
A reproducible firmware build gives us a baseline for testing and change. We separate host-testable logic from the checks that need your target hardware.
- Reproduce the build exactlyWe pin the toolchain and reproduce the build with one command on another machine. We confirm the compiler, C dialect and freestanding or hosted target settings, then compare the output with the firmware you ship.
- Get the logic testable off the deviceWe put hardware access behind a defined interface and build the logic for an ordinary computer. Automated regression tests then cover that logic, with a separate list of checks for the device.
- Turn warnings and analysis on with a budgetWe raise compiler warnings and add static analysis against an agreed warning budget that tightens as the codebase improves. Runtime memory checks run on supported test targets with sufficient resources. We use these tools during testing, with device validation as a separate step.
- Measure before optimising anythingWe measure stack usage, interrupt timing, behaviour under load and the memory map on the real part before optimising. The language alone guarantees neither memory safety nor deterministic timing; the device measurements establish how the firmware behaves.
04Stack
The software around your C component
Firmware connects to a wider application. These technologies provide options for native components, application logic and services collecting device data.
05Questions
Questions about C development and hardware access
A C engagement needs agreement on the target, access to hardware and delivery responsibility. These answers explain how we scope that work.
Yes. Our C engineers take responsibility for the code, build, memory and timing behaviour while working with your hardware and domain specialists.
An architect outside the delivery team reviews the design, and our QA practice covers the code. Choose managed teams when you want a team with unicrew delivery coordination, or custom software development for an agreed outcome.
Choose against the target, compiler support and existing libraries. C is a strong fit when the supplier kit and interfaces already assume it.
C++ offers resource-management abstractions and libraries that can suit embedded work too. An operating system is not the dividing line. We review the part's memory limits, tool support and existing code, including embedded Linux, before recommending either language.
Rust is an option for supported targets, rather than a general replacement for C firmware. We assess Rust for a new, bounded component where its memory-safety properties address a requirement.
The decision also depends on the chip's compiler support, peripheral libraries and supplier kit. Existing C interfaces and reference code remain part of that assessment, along with who will maintain the component.
Yes, for logic that we can separate from hardware access. Final device validation still needs the target hardware and suitable debugging tools.
- Protocol handling, state machines, parsing and business logic can be built and tested on an ordinary computer behind a hardware abstraction.
- Timing, peripherals, power behaviour and chip-specific defects need the real part or a suitable development board, with access to someone familiar with debugging it.
We estimate the first stage after reviewing the build process and target access. The scope depends on whether the toolchain is pinned, whether another machine can reproduce the shipping firmware, and which checks need a device or development board. We agree the build and validation deliverables before estimating the work.
Start with a scoping call with an engineer. We ask for the repository, build instructions and part number to review how the firmware is built.
You receive a written scope covering the repeatable build, hardware-dependent checks and components to retain. Most engagements start within two to four weeks.
We quote C work against the build, firmware and validation scope, using one of three engagement models.
- Time and materials is billed hourly and quoted per project.
- Fixed price is outcome based and quoted per project.
- Team extension is billed monthly per team member.
The estimate accounts for the target toolchain, hardware access and the state of the existing build.
Plan the next release of your firmware
Bring the device requirements and current build process to a scoping call. We will identify what to make repeatable, what to validate on hardware and which working components to retain.