I Spent Months Coding a Flight Controller for a $3 Chip… and It Finally Flew!

Most flight controllers are black boxes. So I built my own, fully open source, running on the cheapest capable microcontroller I could find: the $3 STM32F411 "BlackPill." No RTOS, no framework, just a bare-metal control loop written from the ground up. After a long fight with vibration, dead sensors, and a few crashes, it actually hovers. In this video I break down how PillFlight works: the Mahony attitude estimator with a vibration-aware health gate, the MultiWii style control law, gyro filtering, altitude hold, automatic IMU failover, compass calibration, iBUS telemetry back to the radio, and a flash-persisted blackbox that made every fix possible. Everything is open source. Firmware, full wiring guide, and the PC configurator: GitHub: https://github.com/Arcco-Chakraborty/... Hardware in this build: WeAct BlackPill (STM32F411CE), 100 MHz Cortex-M4F MPU6500 (SPI) primary IMU, MPU6050 (I2C) backup QMC5883L compass, BMP280 baro, VL53L0X ToF FlySky FS-i6 / FS-iA6B radio, F450 frame, 3S LiPo If you are building your own FC on cheap hardware, the failures in here are the useful part. Instrument everything, do not guess. Like and subscribe for more "hardware meets intelligence" builds. #flightcontroller #stm32 #drone #opensource #embedded #blackpill #diyelectronics #robotics