Open 4 Development Platform

Versatile microcontroller evaluation & application development platform

Open4 provides a unique, versatile solution for exploring a variety of new microcontroller technologies, and creating and sharing application ideas. Versatile, low-risk, fun and pertinent, Open4 opens a world of opportunities for your application ideas.

New for STM32F429!

The Raisonance Open4 is a complete development platform capable of supporting a variety of microcontrollers from 8 to 32-bits. Open4 provides a rich range of hardware features for evaluating device characteristics and peripherals. It integrates a complete toolset including debugger/programmer, compiler, integrated development environment and a real time operating system. Its interchangable daughter boards make it possible to try out many MCUs from the same platform and to do much more.

Fun, easy, pertinent MCU evaluation

Open4 makes it easy and fun to start using new MCU technologies. Its hardware features like  color touch screen, codec-based audio, micro SCcard, MEMS accelerometer and IrDA, are pertinent to many everyday applications, enhance tool usability and spice up the user interfaces for a variety of applications.

CircleOS for Open4 implements speeds up creation the user's first applications on a new MCU. The CircleOS API makes it possible to develop applications without getting bogged down in the specifics of peripheral implementation on a new MCU. It also provides easy functions to rapidly and easily upload and execute applications on Open4.

Complete application development platform

Open4 provides everything to code, compile, and debug application software:

  • CircleOS to facilitate implementing device peripherals
  • C compiler for full control of application build and optimization
  • Ride7 integrated development environment for debugging and fine-tuning the application while it runs on the target MCU


Open4 daughter mounted target MCUs allow users to evaluate and debug applications for a wide range of current and future MCUs. Currently supported targets include:

  • STM8L 8-bit low power consumption MCU family
  • STM32E 32-bit ARM Cortex-M3 core-based family
  • STM32C 32-bit ARM Cortex-M3 core-based "Connectivity" family with USB OTG
  • STM32L 32-bit ARM Cortex-M3 core-based "Low Power Consumption" family
  • STM32F4 32-bit ARM Cortex-M4 core-based "High Performance" family