NWBlue Pro H757

PX4 v1.18

WARNING

PX4 does not manufacture this (or any) autopilot. Contact the manufacturer for hardware support or compliance issues.

The NWBlue Pro H757 is a 36 x 36 mm FPV flight controller built around a CubePilot CubeNode H757 module carrying an STM32H757 microcontroller.

INFO

This flight controller is manufacturer supported.

Where to Buy

Order from NWBlue (US).

Specifications

• Processor
  • Main FMU processor: STM32H757 (32-bit Arm® Cortex®-M7 at 480 MHz, 2 MB Flash, 1 MB RAM), on a CubePilot CubeNode module
• Sensors
  • IMU: InvenSense ICM-45686 (SPI3, inside the CubeNode module)
  • Barometer: Infineon DPS368 (SPI3)
  • Magnetometer: ST IIS2MDC (I2C3, internal)
• Interfaces
  • PWM outputs: 9, DShot and Bidirectional DShot capable
  • Serial ports: 6 (TELEM1, TELEM2, TELEM3, GPS1, RC, and a spare receive-only port on the VTX connector)
  • I2C buses: 1 external (on the GPS connector, for an external compass) and 1 internal (magnetometer)
  • CAN buses: 1 (DroneCAN)
  • USB: USB-C
  • RC input: Yes, on a dedicated RC connector
  • SD card: MicroSD slot (SDMMC2)
  • Other: buzzer output (external components required), RGB status LED, SWD
• Electrical data
  • Input voltage: 4S to 12S LiPo on the ESC connector (VBAT)
  • 5 V output: 3.5 A, current limited, shared by the RC, GPS, TELEM and CAN connectors
  • 10 V / 12 V output: 3.5 A, on the VTX and Power Out connectors
  • Power monitoring: battery voltage through an onboard 21:1 divider; battery current from an external current sensor wired to the ESC connector
• Mechanical data
  • Dimensions: 36 x 36 x 18 mm (including connectors)
  • Mounting pattern: 30.5 x 30.5 mm

Manufacturer Documentation

Connector pinouts, wiring diagrams and mechanical drawings are in the NWBlue Pro H757 documentation. 3D models are available on the 3D Models page.

Building Firmware

TIP

Most users will not need to build this firmware. It is pre-built and automatically installed by QGroundControl when appropriate hardware is connected.

To build PX4 for this target from source:

make nwblue_pro-h757_default

Radio Control

A remote control (RC) radio system is required if you want to manually control your vehicle (PX4 does not require a radio system for autonomous flight modes).

You will need to select a compatible transmitter/receiver and then bind them so that they communicate (read the instructions that come with your specific transmitter/receiver).

The RC connector is wired directly to the FMU (UART4) and powered from the 5 V rail. PX4 autodetects receivers on this port that use S.BUS, S.BUS2, Spektrum DSM / DSM2 / DSM-X, Yuneec ST24, Graupner SUMD, CRSF, or GHST. PPM is not supported: the RC pins have no capture channel on the timer that PX4 uses for PPM decoding.

Both TX and RX are broken out, so CRSF and GHST telemetry back to the transmitter works over the same cable.

GPS & Compass

The GPS connector carries GPS1 (UART8) together with the external I2C bus for a compass. The module should be mounted on the frame as far away from other electronics as possible, with the direction marker pointing towards the front of the vehicle.

Pinout

The full pinout with connector locations is on the manufacturer's pinout page.

ESC

Pin	Signal
1	VBAT in (4S to 12S)
2	GND
3	Current sense
4	ESC telemetry (USART1 RX)
5	Output 1
6	Output 2
7	Output 3
8	Output 4

PWM AUX

Pin	Signal
1	Output 5
2	Output 6
3	Output 7
4	Output 8
5	Output 9
6	GND

RC (UART4)

Pin	Signal
1	5V
2	TX
3	RX
4	GND

GPS (UART8)

Pin	Signal
1	5V
2	TX
3	RX
4	SCL
5	SDA
6	GND

TELEM1 (UART7)

Pin	Signal
1	5V
2	TX
3	RX
4	NC
5	NC
6	GND

VTX (USART6)

Pin	Signal
1	10V / 12V
2	GND
3	TX (USART6)
4	RX (USART6)
5	RX (USART2)
6	GND

CAN

Pin	Signal
1	5V
2	CAN_H
3	CAN_L
4	GND

Power Out

Pin	Signal
1	VBAT out
2	GND
3	10V / 12V

SWD

Pin	Signal
1	3.3V
2	SWDIO
3	SWCLK
4	GND

Serial Port Mapping

UART	Device	PX4 Default	Connector	Pins (TX / RX)
USART1	/dev/ttyS0	TEL3	ESC	— / PB7
USART2	/dev/ttyS1	—	VTX	— / PA3
UART4	/dev/ttyS2	RC	RC	PA0 / PB8
USART6	/dev/ttyS3	TEL2	VTX	PC6 / PC7
UART7	/dev/ttyS4	TEL1	TELEM1	PE8 / PE7
UART8	/dev/ttyS5	GPS1	GPS	PE1 / PE0

No port has flow control. USART1 and USART2 are receive-only: only the RX pin is broken out.

TEL3 is the ESC telemetry input and is configured for it by default (DSHOT_TEL_CFG = 103).

PWM Outputs

The board provides 9 PWM outputs, all of which support DShot. Outputs 1 to 4 are on the ESC connector, outputs 5 to 9 on the PWM AUX connector.

The outputs are split across 4 timer groups:

Outputs	Timer
1, 2, 3, 4	Timer1
5, 6	Timer4
7, 8	Timer3
9	Timer2

All outputs within the same group must use the same protocol and update rate.

Bidirectional DShot works on every output except output 6. That output is TIM4_CH4, and the STM32H7 DMAMUX has no request line for it, so the capture DMA needed for the ESC response cannot be set up. Use output 6 for plain DShot or PWM.

OSD

There is no analog OSD chip on this board, so analog video cannot be overlaid. An HD VTX can render the OSD itself over MSP DisplayPort: connect it to the VTX connector (USART6, TEL2) and set MSP_OSD_CONFIG to 102. See OSD for details.

The port is not claimed by default, so it can be used for MAVLink or any other protocol instead.

Battery Monitoring

The board is powered from the ESC connector. The voltage divider is set by default (BAT1_V_DIV = 21.0).

Current sensing is fed from the ESC connector, so BAT1_A_PER_V depends on the current sensor in use and has to be calibrated.

Debug Port

There is no dedicated debug UART. The system console and MAVLink both run over USB. SWD is broken out for use with a debugger.

PX4 Bootloader Update

Boards that ship without the PX4 bootloader must have it flashed before PX4 firmware can be installed. Download the nwblue_pro-h757_bootloader.bin bootloader binary and follow the DFU Bootloader Update instructions.

Once the PX4 bootloader is flashed, firmware can be installed normally via QGroundControl.