Implementing Position Hold using Optical flow sensor and ToF on Litewing ESP32 Drone

Implementing autonomous position hold on the Litewing ESP32 Drone relies on a combination of visual surface tracking and precise distance measurement to maintain a stable hover without relying on external GPS signals. At the heart of this system is the Litewing Flight Positioning Module, which houses a PMW3901MB optical flow sensor and a VL53L1X Time-of-Flight (ToF) sensor. The optical flow sensor acts essentially like an inverted computer mouse, taking high-speed sequential images of the ground beneath the drone to detect relative surface movement in the X and Y axes using dead reckoning algorithms. Simultaneously, the VL53L1X ToF sensor emits infrared laser light and measures the time it takes for the photons to bounce back from the ground, providing accurate, real-time altitude (Z-axis) data. The ESP32 DevKit v1 microcontroller reads data from both sensors via communication buses, processing the optical shifts and height measurements to calculate how much the drone is drifting. By running Python scripts utilizing the cflib library and CRTP communication over UDP, the ESP32 dynamically adjusts the motor outputs of the Litewing ESP32 Drone to counteract drift, locking the aircraft into a steady, stationary position in mid-air.