The link to video about how to use : https://www.youtube.com/watch?v=kwGj5dX-T-A PLS NOTE: The one selling is not made by Seriously Pro, but the perfect replacement.
Features: No-Compromise I/O Use all the features all the time; e.g. Connect your OSD + SmartPort + SBus + GPS + LED Strip + Battery Monitoring + Sonar + 8 motors - all at the same time!
Configurable The F3 runs Cleanflight which can be configured to suit your needs using a cross-platform GUI (Windows/OSX/Linux).
Tiny and lightweight The F3 has a standard 35x35mm form-factor with 30mm mounting holes and weighs just 6 grams.
Flight Logging On-board high-capacity black box flight log recorder - optimize your tuning and see the results of your setup without guesswork.
Next-Generation CPU The F3 has an ARM Cortex-M4 72Mhz CPU with Math co-processor (FPU) for efficient flight calculations that gets more done in less time. Loop times up to ~2x as fast as previous-generation STM32F1 based boards.
Developer Friendly Developer friendly debugging port (SWD) and boot mode selection, unbrickable bootloader.
OneShot ESC Full support for OneShot ESCs for easy PID tuning and a sharper response.
Broad RC receiver Support Supports SBus, SumH, SumD, Spektrum1024/2048, XBus, PPM, PWM receivers. No external inverters required (built-in).
Programmable LED Dedicated output for programmable LEDs - great for orientation, racing and night flying.
Battery Monitoring Battery monitoring ports for voltage and current.
Sonar Sonar support for precision low-altitude hold.
I2C Port I2C port always powered, perfect for external sensors or always-on OLED Screen.