Firmware Design and Implementation for a Quadrotor UAV

In recent years UAVs (unmanned aerial vehicles), also called drones for simplicity, are becoming more and more widespread all over the world. Born for military employment, now they are used for everyday tasks and also in the field of research. Here we want to show our implementation of a working firmware for UAV. The firmware main task is to link the software and the hardware. This is a key aspect because all sensors, motors and communication board must exchange a big quantity of data with each other. Moreover, those data are inputs or outputs of the software that is the 'brain' of the drones. The software is loaded into a ST micro-controller and is capable to get all needed information from others hardware peripherals thanks to dedicated libraries. A final state machine that controls the global state of the drone handles his behaviour. Starting from the initialization, it switches in a runtime phase only if no errors occur. Errors detection is in charge of the commander functionality, which is always active like an external supervisor. Moreover, the firmware should include the data treatment, to guarantee correctness and synchronization of data with a specific module. Finally, another module is the control algorithm, for studying the drone behaviour. For safety motivations, also a manual mode is added with which you can control the drone using a joystick. All of these modules are implemented for a quadrotor UAV, designed at Politecnico di Torino in the Department of Mechanical and Aerospace Engineering. The firmware, afterward analysed, is overall working and it can be used with the target hardware. In the future, more functionalities can be added with different purposes.