Introduction A flight controller with a builtin Serial ELRS receiver and 4IN1 BL S 12A ESC specially developed for Digital HD FPV which removes the analog OSD chip 7456 optimizes the PCB layout and supports 1 2S Lipo LiHV lithium batteries very Suitable for Digital HD Tinywhoop Cinewhoop Toothpick and other small FPV drones The flight controller uses the F405 chip supports Betaflight INAV firmware has 3 sets of complete UARTs available and integrates a BMP280 barometer and 8Mbp blackbox which greatly enhances the playability of the flight controller Specification Brand HappymodelModel CrazyF405HDItem Name F4 Flight Controller AIO 12A 4in1 ESC ELRS ReceiverMount size 25 5x25 5mmWeight 4 8g without power lead wire Flight ControllerMCU STM32F405RGT6 168MHZ 1Mbyte FLASH GYRO Sensor BMI270 SPI connection Mount hole size 25 5mm 25 5mmPower supply 1 2S battery input DC 2 9V 8 7V Built in 12A each Blheli S 4in1 ESCBuilt in Serial ExpressLRS 2 4GBuilt in BMP280 BarometerBuilt in 8MBp blackboxBuilt in voltage meter sensor voltage meter scale 110Built in current meter sensor current meter scale 470Onboard 4in1 ESCPower supply 1 2S LiPo LiPo HVCurrent 12A continuous peak 15A 3 seconds Support BLHeli S Bluejay firmwareFactory firmware Bluejay ESC V0 19Firmware target Z H 30Default protocol DSHOT300When use 1s battery and high KV 0702 0802 motors should set startup power to 1100 1200Onboard UART ExpressLRS 2 4GHz ReceiverPacket Rate option 25Hz 50