Emulation of the Crazyflie 2.1 Hardware for Embedded Control System Testing

Abstract: Embedded systems are hard to debug and the field of control software testing is relatively unexplored. Progress in these areas could provide better testing heuristics and safer systems. More specifically, hardware emulation is a potentially powerful tool that can help improve the speed and quality of the development cycle. Therefore, this study developed a hardware emulator for supporting embedded testing, debugging and development. As target hardware, the Bitcraze Crazyflie 2.1 quadcopter was used. The emulation was done in the open source framework Renode. The development of the emulator is accompanied by a discussion on the uses both in the industry and research environments. In order to set up the emulation, we extended Renode by implementing different peripherals such as sensors, the EEPROM and a basic timer. These, together with the created platforms were pushed to the forked Bitcraze Renode repositories. The repositories are open source and available for future research projects to use. The emulator allows interactive use to debug and explore the virtual system without extra hardware. It can also be setup to automatically test proposed firmware changes. The usage is showcased in several test cases, where different bugs have been injected into the firmware and then found using the emulation. The main goal for the thesis was to run the same firmware as used in real Crazyflies and pass a built-in, start-up, self test. Accuracy of hardware emulators is also an open research problem. As such, the thesis provides a thorough discussion on the accuracy of the proposed tool. The discussion also includes possible future work to improve it.