The RTEdbg open source toolkit helps embedded developers test, debug, and optimize C/C++ firmware. It provides functions for non-intrusive data logging, data transfer to host, and decoding utilities that enable deeper insight into real-time systems. Unlike traditional debuggers, this solution doesn't stop the embedded system, preserving its natural behavior. It's suitable for large RTOS-based systems as well as small, resource-constrained systems. The solution is the equivalent of a re-entrant, time-stamped fprintf() running on the host instead of the embedded system. The fprintf functionality provides flexibility in data formatting and allows the logging data to be sorted into multiple files for later analysis with common tools such as CSV and LOG readers.