Preparing for the upcoming events “Robotchallenge” in Vienna and the “Istrobot” in Bratislava I implented an own altitude hold for my hobby quadcopter. RC input is read by an STM32F103, which is going to act as a full autopilot for the challenges. It probes the sensor and generates the needed throttle output using a PID controller. RC output is generated as sum signal and connected to a Flip32 FC running Cleanflight. Next step: Full control through image processing done by an Odroid C1, connected to the stm32. The Quadcopter is based on the “GoFly Travel v2” from “der Frickler” ( http://der-frickler.net/modellbau/planes/gofly_travel ).