NXP’s FreeMASTER tool has been empowering embedded developers, with real-time visibility, for over two decades. Whether you're tuning a motor control loop, monitoring sensor performance or building a custom user interface, FreeMASTER provides a fast, flexible way to interact with your embedded application—without halting execution.
Originally created to support motor control applications, FreeMASTER has grown into a go-to tool for engineers needing to get insight into what's happening on the microcontroller—right now. It connects via serial, joint test action group (JTAG), USB, controller area network (CAN) or Ethernet, visualizes data in real time and can even automate testing or tuning workflows through scripting.
Explore how FreeMASTER continues to evolve and where it's headed next. Dive deeper by listening to our EdgeVerse Techcast episode on Apple podcasts , Spotify or YouTube .
FreeMASTER is designed to give developers a better way to observe and interact with embedded systems as they run. Traditional debuggers often require breakpoints, disrupting real-time operation. FreeMASTER offers a non-intrusive alternative—providing live insights without stopping execution. Its open architecture allows connections via a variety of interfaces, including debug probes, USB, Ethernet and CAN.
Variables can be visualized graphically, modified on the fly or accessed through automation scripts. Developers can even build their own dashboards using JScript, Python, Excel, MATLAB or integrate FreeMASTER with custom user interfaces (UIs) through GUI Guider.
Though FreeMASTER was initially developed for motor control applications, it now supports a wide range of use cases. From sensor tuning and analog front-end configuration, to visualizing game telemetry on a microcontroller-based Doom demo, FreeMASTER provides the flexibility to adapt to virtually any embedded scenario.
Its strength lies in the ability to create custom scopes, adjust parameters in real time, convert data formats on the fly and visualize performance metrics—all without writing additional code.
Over the years, FreeMASTER has added robust scripting support and third-party integration with tools like Excel and Simulink. It supports a wide range of NXP microcontrollers, from legacy 8-bit devices to the latest Arm® Cortex®-M-based portfolios like MCX and i.MX RT.
Support for a wide range of communication protocols—including serial, CAN, USB, Ethernet and even Wi-Fi—means that the tool is useful throughout the development cycle, from bare-board prototyping to deployed systems.
FreeMASTER continues to evolve. Recent enhancements include integration with Zephyr RTOS, enabling developers to monitor task central processing unit (CPU) usage, stack utilization and application variables within the same interface. There are also efforts underway to bring FreeMASTER support to macOS and Linux platforms, expanding accessibility for cross-platform development teams.
Ready to try FreeMASTER? Visit the FreeMASTER tool page or NXP’s Application Code Hub for more than 25 example projects, training videos and a dedicated support community .
Michal Hanak is technical lead for the software team responsible for development of FreeMASTER and other tools at NXP Semiconductors. Michal has 28 years of experience in C/C++ development for embedded systems and Windows, FPGA design and communications with a focus of interconnecting embedded applications with host computers.