Another project with the same Arduino+Raspberry approach with video and control over WiFi that we used in hexacopter. We used non-typical configuration of legs and developed our own inverse kinematics algorithm, optimized for calculations on Arduino (using several simplifications, all 18 servo positions were calculated in less than 10 milliseconds on 8-bit 16-MHz MCU for any target state) – again, no stm32 at that time ))