LoopCheck replaces building your own test infrastructure with a complete testing platform that we tailor to your application – based on a proven, adaptive hardware platform instead of a from-scratch development. From connected devices to safety-critical applications, your engineers start testing from day one.
Basics
What is Hardware-in-the-Loop?
Hardware-in-the-Loop (HIL) is a test method in which your real embedded controller runs against a simulated environment. The test system feeds in sensor and fieldbus signals, reads the firmware’s responses back and checks them automatically against expected limits – reproducibly and without the real plant. That lets you exercise control algorithms, fault cases and edge conditions safely at your desk instead of on an expensive test rig.
LoopCheck covers the full range – from module tests of individual components to black-box system tests of the finished firmware. As a compact HIL for the developer workstation (desk HIL), it is small enough for any desk, integrated into CI/CD and driven with tests in C, C++ or Python.
Where it fits
Not all HIL is the same
Desk HIL vs. rack HIL
Desk HIL sits on the developer’s desk and tests individual controllers early and often. Rack HIL are large cabinet systems for the full vehicle or plant – expensive, shared and rarely free. LoopCheck is desk HIL: there when you need it.
Signal HIL vs. power HIL
Signal HIL works at signal level – sensor values, bus signals, small currents and voltages – ideal for firmware and control testing. Power HIL switches real load currents and power. LoopCheck is a signal HIL: precise, safe and exactly right for embedded software.
Embedded testing shouldn’t be a project of its own
Most HIL systems are expensive and complex. Teams that build their own test infrastructure spend more time maintaining it than building their actual product: custom hardware development, hardware/software integration, sensor and peripheral simulation, logging, signal generation and the upkeep of a real-time HIL.
Before the first useful test even runs, an in-house build moves through research, hardware, software and testing – each phase adding engineering hours. The result is long development cycles, expensive validation and bugs found too late.
Your engineers should build products, not test infrastructure.
The solution
What we handle for you
Hardware adoption
We adapt the test hardware to your device under test – no board bring-up on your side.
HW/SW integration
Firmware and adapter board are matched to your interfaces out of the box.
Communication interfaces
CAN, Ethernet, UART, RS485 and more – wired to your connectors.
Real-time execution
Deterministic, microsecond-level timing on a dedicated core.
Signal generation
Analog and digital stimuli, including sensor and peripheral simulation.
Automation & logging
A test API and CI/CD-ready workflow instead of manual bench work.
Tests in C, C++ or Python
Your engineers shouldn’t have to learn another proprietary ecosystem. With LoopCheck they simply write tests in the languages your team already uses – no proprietary scripting language, no forced IDE, no long training period.
Time-critical test logic and simulation models run in C on a dedicated processor core on the board, in real time – reached through a clean API instead of registers and pin numbers. From the host you drive that logic with an ordinary Python library: start sequences, set variables, read back timestamped results. And because the tests are plain C, C++ and Python, AI coding assistants understand them out of the box.
The platform
Adaptive hardware – configured by us per application
Adaptable docking shields
Screw terminals, coaxial analog frontends, power stages or a fully custom connector layout – on a proven base board.
Fieldbus & networking
CAN / CAN FD, Ethernet and serial interfaces (UART, RS485 / RS422) to wire up your device under test for real.
Analog & digital I/O
Precise analog inputs and outputs as well as digital signals – instead of simulation only.
Dedicated real-time core
A core of your own for your C code delivers deterministic, hard real-time behaviour.
Safety
Qualifiable for safety-critical systems
Traceability
Requirements, test cases and results linked end to end.
Verification evidence
Reproducible test execution and dependable evidence for verification.
Qualification support
Assistance with qualifying the tool and the test environment.
Safety-lifecycle integration
Fitting testing into your V-model process – including recurring re-validation.
Automated, reproducible HIL tests map directly onto the verification side of the safety lifecycle. The evidence fits into processes under ISO 26262, EN 50128 / EN 50657, IEC 61508, IEC 62304 and DO-178C – the relevant standard and safety integrity level are agreed per project.
For medical devices in detail: HIL testing for IEC 62304.
References
Proven in real projects
Multi-channel motor control
Drives and sensors simulated as the counterpart, the tests fully automated in CI/CD.
Medical laser controller
Bit-level SPI verification and deliberate fault injection – without any real laser system.
SIL 3 safety sensor
Module and system testing with code-coverage evidence over the trace port.
Frequently asked questions about HIL testing
What is Hardware-in-the-Loop (HIL)?
A test method in which the real embedded controller runs against a simulated environment: the HIL test system generates the sensor and bus signals, reads the firmware responses back and checks them automatically – reproducibly and without the real plant.
What is the difference between desk HIL and rack HIL?
Desk HIL sits on the developer workstation and tests individual controllers early and often. Rack HIL are large, expensive cabinet systems for the full assembly that are usually shared. LoopCheck is a desk HIL.
Signal HIL or power HIL – which is LoopCheck?
LoopCheck is a signal HIL: it simulates at signal level (sensor values, bus signals, small currents and voltages) and is ideal for firmware and control testing. Power HIL with real load currents is a different field.
Does LoopCheck support module tests and black-box tests?
Yes. LoopCheck covers module tests of individual components through to black-box system tests of the finished firmware – including deliberate fault injection. That is particularly relevant for medical technology under IEC 62304.
Is LoopCheck suitable for safety-critical and medical applications?
Yes. Reproducible, automated HIL tests provide verification evidence for standards such as IEC 62304 (medical), IEC 61508, ISO 26262, EN 50128/50657 and DO-178C. The relevant standard is agreed per project.
Which languages do I write tests in?
In C, C++ or Python – no proprietary ecosystem and no forced scripting language. Time-critical logic runs in C in real time on the board, driven from the host through a Python library.
Start testing instead of building test infrastructure
All the technical detail – hardware configurations, the Python API, architecture and a complete worked example – is on the LoopCheck platform.
- Tests in C, C++ or Python – no proprietary ecosystem
- Integrated into CI/CD: automated regression and nightly tests
- Real, adaptive test hardware instead of simulation only
- Qualifiable for regulated, safety-critical devices
