Matek RC Helicopter Flybarless Controller G474-HELI
by Matek Systems

Specifications

• MCU: STM32G474CE, 170MHz Cortex-M4 , 512KB Flash
• IMU: ICM42688-P
• Baro: SPL06
• Blackbox: 128MB Flash (1G-bit NAND)
• 3x UARTs (1, 2, 3)
• 1x I2C
• 8x PWM (4x Servos, 2x Motors, RPM, LED)
• 2x ADC (VBAT, Current)
• USB Type-C(USB2.0)

Electrical characteristics

• Input voltage range: 5.4V~30V (2~6S LiPo)
• No current sensor integrated, support external 3.3V based current sensor.
• Battery Voltage divider 1K:10K (Scale 110)
• BEC 5V 2A for FC and peripherals
• BEC Vx 5A cont. 8A Peak for servos (5V, 7.2V option)
• 3.3V 300mA

Firmware/config

• Rotorflight  / MATEKG474HELI

Physical

• Mounting: 20 x 20mm, Φ4mm with Grommets Φ3mm
• Dimensions: 38 x 26 x 13 mm
• Weight: 15g (w/o pins)
• 3D step file

Including

• 1x G474-HELI
• 1x PicoBlade 1.25mm Servo adapter (M2/S2 servos)
• 1x 20cm JST-GH-4P to JST-GH-4P cable
• 1x 20cm JST-GH-6P to JST-GH-6P cable
• Dupont 2.54 pins  (Board is shipped unsoldered)

Tips

If GPS, Receiver or other peripherals are connected to UART2(Tx2,Rx2)  and these peripherals are powered ON while connecting USB.   STM32G474 will not go into DFU mode. It is related to DFU protocol used in the STM32G474 bootloader.  Pls unplug peripherals from UART2 before you try flashing the FC.
There is no UART4 breakout on this board.

If using Frsky SBUS+SmartPort receivers. you may remap one of PWM pins to softserial_tx for SmartPort, e.g.  LED pin,  resource serial_tx 11 A15 , feature softserial .
You can also resource LED pin to RX2 for ESC telemetry,  ” resource LED_STRIP 1 none,  resource SERIAL_RX 2 A15 “

Due to leakage voltage on MCU I/O, there is floating current readout when no external current sensor connected.  If you don’t use external current sensor.   set current_meter = NONE .
If the FC is mounted with arrow facing backward.   set gyro_1_sensor_align = CW0FLIP 
Blheli bi-direction Dshot ESC,  enabled RPM filter:  feature rpm_filter

Add Matek Hall Sensor:

CLI command

    resource SERIAL_RX 2 none
    resource ADC_CURR 1 A03
    set ibata_scale = 200

    resource SERIAL_TX 2 none
    resource ADC_BATT 1 A02
    set vbat_scale = 210

Download latest RotorFlight configurator from here.  https://github.com/rotorflight/rotorflight-configurator/releases