Meet the ArduBee: an open source, modular drone based on ArduoPilot that can fly indoors and outside. It has bruhsless motors, WiFi, and other smart components to get off the ground. This drone weighs only 100g grams with its battery and motors. It measures 15cm from motor to motor.
The ArduBee has a STM32H743VIT6 480 MHz ARM Cortex M7 processor, BMi088 IMU, IST8310 compass, and a Li-Ion battery. You can record logs to a MicroSD card. Like what you see? You can back this project on Kickstarter.