an affordable system for automated tests

Hardware in the Loop

Hardware-in-the-loop Testing

Try the beta version of the graphical hardware configuration for miniHIL and let us know what you think!

Hardware-in-the-loop (HIL) is a technique that is used for testing complex real-time embedded systems. Real-world testing of embedded control systems can be complex, expensive, and hazardous. HIL simulation lets engineers efficiently test embedded systems in a virtual environment. A HIL system must emulate sensors and actuators to interface the system under test with the environment. The key benefits of HIL testing are:

  1. Reducing time to market
    E.g. before a mechanical engine is available, a major part of the testing of the ECU can already be finalized.
  2. Improvement of testing quality
    E.g. failure conditions can be documented and easily repeated.
  3. Improved safety and standards conformity
    E.g. according to ISO 26262, the role of simulation is crucial for the validation of system behavior, and recommends simulation at all levels.
  4. Cost reduction
    E.g. building and testing HIL systems can be drastically less expensive than testing (and maybe damaging) real systems

Since HIL testing allows to find problems at an early stage, the cost for fixing them drops significantly. However, full-blown HIL systems can be complex and expensive. Hitex in cooperation with Protos has created an affordable system for automated tests.


The system is especially suited for the following

Use cases:

  • Development accompanying HIL test for microcontroller systems
  • HAL (hardware abstraction layer) Test
  • Driver Test
  • MCAL Test

Environment simulation:

  • Device simulation (e.g. Flash, RAM, gate driver)
  • Interface simulation (e.g. SPI, I2C, UART, analog, digital)
  • sensor simulation
  • Battery simulation and battery management

Bus simulation:

  • Test of CAN Bus protocols
  • Test of LIN bus protocols
  • Test of TCP/IP bus protocols
  • Test of UART bus protocols
  • Test of XCP bus protocols
  • Test of custom protocols

Test and Simulation for Motor Control Software:

  • BLDC and DC motor control
  • Universal motor control
  • Sensorless control with single shunt and dual shunt
  • Motor control with sensors (Hall and angle sensors)

Description of the test system

A test hardware (system test/miniHIL) is available for tuning and testing the hardware under test. The device under test (DUT) is connected to the system test/miniHIL. A variety of target adapter boards for various microcontrollers is available for the system test/miniHIL. Of course proprietary hardware can also be connected via custom adapters. Hitex can assist in design and development of specialized interface boards.

Description of the miniHIL test system

The system test/miniHIL base is equipped with a powerful microcontroller performing the stimulation in real time with the above-mentioned simulations and protocols. For particularly real-time critical signals (e.g. SPI slave), an optional FPGA board is available.

A comprehensive test suite controls the system test/miniHI. The test software makes the hardware signals available in form of model-based adapters. The complete testing environment is defined in a graphical environment. For each PIN of the system test/miniHIL there is a port with protocol in the model, which can then be accessed comfortably by the test creator. In order to create the tests, models such as state machines are available. For complex systems such as engine simulations, Simulink models can be integrated.

These models are controlled using the CaGe test language. CaGe allows the definition of test suites, test sequences and test steps. Once the complete test setup is defined, the code for the test system can be automatically generated and downloaded into the sytem test/miniHIL.

The tests can then be carried out specifically from the test environment or completely automated. Test results are logged.

A comprehensive test suite controls the system test/miniHI

Available system parts:


  • miniHIL software license for tester (to carry out tests)
  • miniHIL software license for developer (for creation of test cases and scenarios)
  • miniHIL software continuous integration server license
  • miniHIL software target adapter license


  • miniHIL Base test board
  • miniHIL FPGA expansion board
  • miniHIL target adapters for a variety of controllers


  • Development of special target adapter
  • Setup of complete test setup for customer specific hardware
  • Execution of system test
  • Development of customer specific protocols
  • Development of customer specific simulation