CruxF405HD ELRS 3-in-1 AIO Flight Controller – Built-in UART 2.4G ELRS & 20A ESC for Toothpick (20×20mm)
CruxF405HD ELRS 3-in-1 AIO Flight Controller – 20×20mm for Toothpick & Long-Range FPV
The CruxF405HD ELRS AIO flight controller is an all-in-one solution for 3-4S Toothpick or long-range FPV drones. It integrates a 20A Blheli_S ESC, UART 2.4GHz ExpressLRS receiver, BMP280 barometer, and supports plug-and-play DJI HD equipment with a reserved 6-pin socket.
Key Features:
- MCU: STM32F405RGT6 (168MHz, 1MB FLASH)
- Gyro Sensor: ICM42688 (SPI connection)
- Mount hole size: 20×20mm
- Power Supply: 3-4S LiPo (DC 11-17.4V)
- Built-in 20A Blheli_S 4-in-1 ESC (continuous 20A, peak 25A for 5s)
- Supports DSHOT150/300/600
- Built-in Serial ExpressLRS 2.4GHz receiver (CRSF protocol)
- Packet Rate Options: 25Hz/50Hz/150Hz/250Hz/500Hz
- Built-in BMP280 barometer for altitude measurement
- Built-in 8MB blackbox, voltage & current sensors (Voltage: 110, Current: 470)
- Factory firmware: Bluejay 0.19.2
- Reserved 6-pin socket for DJI HD plug-and-play
Binding Procedure:
- Power the FC via USB, wait until red LED turns off, then power off. Repeat twice. On the third power-up, red LED double-flashes indicating bind mode.
- Use ExpressLRS.lua from your radio transmitter’s “TOOLS” menu and hit [Bind].
- Red LED Status:
- Solid: Bind successful
- Double-flash: Enter bind mode
- Slow flash: No RC signal
- Continuous fast flash: ExpressLRS WiFi enabled
- Tri-flash: Model mismatch (adjust Model Match tab)
UART Description:
- ELRS receiver connected to UART2 by default
- UART1 or UART6 can be used for MSP OSD with HD VTX
- UART6 can be used for GPS or other serial devices
- IRX6 is inverted serial RX6 for SBUS input (cannot be used simultaneously with TX6/RX6)
NOTES:If you want to use Barometer and want to upgrade firmware to betaflight 4.4.x ,you need to add custom Defines “BARO_DPS310 ACC_SPI_ICM42688P GYRO_SPI_ICM42688P” from build configuration of betaflight configurator before load online firmware otherwise gyro will not working . 
Enabled Barometer steps:After re-flashed firmware successfully , please connect to betaflight configurator and go to CLI command ,then type the following command:
resource I2C_SCL 2 B10
resource I2C_SDA 2 B11
set baro_bustype = I2C
set baro_i2c_device = 2
save
Default port settings:
If you want to use DJI Radio Controller , please change to the following settings:
CruxF405HD ELRS 3-in-1 AIO Flight Controller – Built-in UART 2.4G ELRS & 20A ESC for Toothpick (20×20mm)
Description
CruxF405HD ELRS 3-in-1 AIO Flight Controller – 20×20mm for Toothpick & Long-Range FPV
The CruxF405HD ELRS AIO flight controller is an all-in-one solution for 3-4S Toothpick or long-range FPV drones. It integrates a 20A Blheli_S ESC, UART 2.4GHz ExpressLRS receiver, BMP280 barometer, and supports plug-and-play DJI HD equipment with a reserved 6-pin socket.
Key Features:
- MCU: STM32F405RGT6 (168MHz, 1MB FLASH)
- Gyro Sensor: ICM42688 (SPI connection)
- Mount hole size: 20×20mm
- Power Supply: 3-4S LiPo (DC 11-17.4V)
- Built-in 20A Blheli_S 4-in-1 ESC (continuous 20A, peak 25A for 5s)
- Supports DSHOT150/300/600
- Built-in Serial ExpressLRS 2.4GHz receiver (CRSF protocol)
- Packet Rate Options: 25Hz/50Hz/150Hz/250Hz/500Hz
- Built-in BMP280 barometer for altitude measurement
- Built-in 8MB blackbox, voltage & current sensors (Voltage: 110, Current: 470)
- Factory firmware: Bluejay 0.19.2
- Reserved 6-pin socket for DJI HD plug-and-play
Binding Procedure:
- Power the FC via USB, wait until red LED turns off, then power off. Repeat twice. On the third power-up, red LED double-flashes indicating bind mode.
- Use ExpressLRS.lua from your radio transmitter’s “TOOLS” menu and hit [Bind].
- Red LED Status:
- Solid: Bind successful
- Double-flash: Enter bind mode
- Slow flash: No RC signal
- Continuous fast flash: ExpressLRS WiFi enabled
- Tri-flash: Model mismatch (adjust Model Match tab)
UART Description:
- ELRS receiver connected to UART2 by default
- UART1 or UART6 can be used for MSP OSD with HD VTX
- UART6 can be used for GPS or other serial devices
- IRX6 is inverted serial RX6 for SBUS input (cannot be used simultaneously with TX6/RX6)
NOTES:If you want to use Barometer and want to upgrade firmware to betaflight 4.4.x ,you need to add custom Defines “BARO_DPS310 ACC_SPI_ICM42688P GYRO_SPI_ICM42688P” from build configuration of betaflight configurator before load online firmware otherwise gyro will not working . Enabled Barometer steps:After re-flashed firmware successfully , please connect to betaflight configurator and go to CLI command ,then type the following command:
resource I2C_SCL 2 B10
resource I2C_SDA 2 B11
set baro_bustype = I2C
set baro_i2c_device = 2
save
Default port settings:If you want to use DJI Radio Controller , please change to the following settings: