The paper proposes a new didactic platform for practical study of embedded Real Time Operating Systems (RTOSs). Three fundamental parts that are included in the platform are discussed in detail: the hardware part, the firmware part and the software tools. In the description of the hardware part the following parts are addressed: main controller, input/output module, executing module and programmer module. The project of the hardware part is distributed according to GPLv2 license. The firmware of the platform is based on FreeRTOS distributed according to the modified GPL license, ported by the authors on the microcontrollers not originally supported, i.e., Atmega128 and Atmega168.