Guide:

Manual:

Discussion:

Features

Optimization for Cleanflight/Betaflight firmware – (flash as spracing target)
ARM Cortex-M4 core STM32F303CC with 32bit/72MHz/256K Flash/40K SRAM and hardware floating point unit
MPU6050 and BMP180 / BMP280 Sensors
Build-in 8MB flash for black box log recorder
On board OSD with absolutely original MAX7456EUI+ and standard FTDI debug port
Receiver connector with PPM/SBUS/SumD/DSM2/DSMX and RSSI input
Up to 3 serial ports and 8 PWM outputs
Multifunction connectors with SWD/UART2~3/Soft-serial/Buzzer/LED trip/Voltage detection
Multifunction OSD connectors with video_IN/ video_OUT/ICSP/debug port (UART1)
PDB connector with 5V input/Current and Voltage detection
Power input reverse polarity protection

Specification

Power input:5.0~5.5V
Dimension:35x35x9mm
Fixing hole spacing:30mm
Weight:7.3g
PPM/RSSI/SBUS/SumD Receiver Cable
Camera/video-TX cable
Buzzer/LED strip/voltage detect cable
OSD debug port to FTDI adapter cable

If your Drones doesn’t PDB, you can use BR-PDB, it is the best solution for BRF3:
http://www.rctimer.com/product-1593.html

If BR-PDB work with BRF3, you need reset the Voltage scale to “210“: