This paper presents the architecture of a microcontroller abstraction layer that allows hardware independence. Existing abstraction systems do not have as much flexibility when it comes to the hardware used. The most common case is that the "microcontroller abstraction layer" is considered to generate a piece of software that helps in faster configuration, but still serves to develop software for a particular microcontroller. The BM_HAL layer, developed for microcontroller abstraction, also allows application execution in a virtual environment. When developing in the application layer, the programmer has the ability to choose on which system the executable file will be executed. One preprocessor command selects which system it is. It is currently possible to work with the STM32F103C8 microcontroller and work in the virtual environment of the Windows operating system. A development engineer using a common API, called BM_HAL, has the ability to write program code without thinking about the physical layer, and when he wants to test an application, all he has to do is define the target platform. After compiling, the application can be run on a predefined desired system without any additional changes. In addition to software and drivers, two boards with STM32F103C8 microcontroller, required to demonstrate the operation of the abstraction layer, were made. The boards are connected via a twisted pair through which communication via CAN protocol takes place. For the purpose of demonstrating the operation of the BM_HAL abstraction layer, an application with graphical user interface has been developed, which enables the setting of virtual inputs and outputs.