Systems for harsh environments often use embedded processors for tasks that require reliability. However, harsh environments cause faulty behavior in electronics, which eventually lead to system failure. Therefore, embedded processors must use techniques to improve their reliability. In this context, this work presents the implementation and characterization of a RISC-V-based system-on-chip. We characterized our implementation by carrying out test campaigns at the ChipIr irradiation facility. This facility provides a beamline for testing electronics against neutrons, mimicking atmospheric-like environments. With this first test campaign, we identified the most critical parts of our system-on-chip and essential tips to improve the test effectiveness. In the second test campaign, we used an improved version of the system setup with higher reliability error observability features. The version embedding all the hardening techniques could correct or mitigate 98.1 % of the detected upsets under irradiation.