Happymodel CrazyF411 ELRS AIO 4in1 Flight Controller Built-in UART 2.4G ELRS Receiver 20A ESC for Crux35 Toothpick FPV Racing Drone Introduction: The CrazyF411 ELRS flight controller comes with integrated UART 2.4GHz ExpressLRS receiver and 20A Blheli_s ESC(Bluejay firmware pre-installed) which could support 2-4s. Bigger Mosfet could support high to 20A currents would be better for 2-4S toothpick drone or long range FPV drone. And because the 2.4GHz ExpressLRS receiver is equipped with the SX1280 radio frequency chip with high sensitivity, high packet rate and low latency, this flight controller is the one that all Race/Freestyle pilots needed. The built-in ELRS receiver is UART communication with MCU, it’s the same like Happymodel EP1 which you can update firmware by betaflight pass-through or WIFI, very simple. The default firmware is ELRS V3.0.1. This flight controller would be used for Crux35 to instead ELRS X1 flight controller. Specification: Brand: Happymodel Model: CrazyF411 ELRS Item Name: F4 Flight Controller AIO 20A ESC UART 2.4G ELRS Receiver Mount pattern: 25.5×25.5 M2 Size:32*28*9mm --Flight Controller: MCU:STM32F411CEU6 (100MHZ, 512K FLASH)Sensor: ICM42688P or BMI270 (SPI Control) Power supply: 2-4S Lipo battery Built-in 20A Blheli_s ESC each Built-in Betaflight OSD(SPI Control) Built-in UART ExpressLRS 2.4GHz receiver Built-in 5V 1.5A BEC Flight controller firmware target: CRAZYBEEF4DX --Onboard 4in1 ESC: MCU upgraded to EFM8BB21Power supply: 2-4S LiPo/LiPo HV (7v/17v) Currents: 20A continuous peak 25A (5 seconds) Support BLHeliSuite programmable Factory firmware: Bluejay 0.18.1Firmware target: F_H_40_48_v0.18.1 Default protocol: DSHOT150/DSHOT300/DSHOT600 --Onboard UART ExpressLRS 2.4GHz Receiver: Packet Rate option: 25Hz/50Hz/150Hz/250Hz/500HzRF Frequency: 2.4GHzAntenna plug: IPEX Telemetry output Power: