H743 Flight Controller

CBUnmanned H743 Stamp

The CBUnmanned H743 Stamp is a flight controller loosely based on the FMUv6 standards & is designed for low volume OEMs as a drop in way to add ArduPilot to their custom hardware builds. It is a part of CBUnmanned's wider "Stamp" Eco-System, which brings together all the typical avionics hardware into a neat custom carrier PCB. Mounting footprints and symbols are available along with examples of basic usage on the Wiki.

Features

• Class leading H7 SOC.

• Triple IMU sensors for extra redundancy.

• Based on FMU-V6

• Direct solder mounting or optional 1.27mm header.

• x1 Ethernet and x2 CAN for easy integration with the next generation of UAV accessories.

• All complicated/supporting circuitry is on-board, just power with 5v.

• Just 22mm x 24.25mm & 1.9g

Specifications

• Processor

  • STM32H743IIK6 microcontroller

  • 480MHz

  • 2Mb Flash

  • 1Mb RAM

• Sensors

  • x2 Ivensense ICM-42688 IMU

  • x1 Ivensense ICM-42670 IMU

  • x1 Infineon DPS310 Barometer

  • x1 Bosch BMM150 Magnetometer

• Power

  • 5v Main Power in

  • x6 Independent Power Regulators

  • x2 ADC Inputs for Voltage and Current Sense

• Interfaces

  • x1 MicroSD card slot

  • x8 UARTs inc RC, x3 with flow control

  • x10 PWM outputs

  • x2 I2C

  • x2 CAN

  • x1 External SPI

  • x1 Ethernet

  • External Buzzer

  • External Safety Switch

  • External USB connectors

Pinout

UART Mapping (Yellow Fade)

Ardupilot -> STM32

• SERIAL0 -> USB

• SERIAL1 -> USART1

• SERIAL2 -> USART2 (With RTS/CTS)

• SERIAL3 -> USART3

• SERIAL4 -> UART4

• SERIAL5 -> UART5 (With RTS/CTS)

• SERIAL6 -> USART6 (Sbus In / IO coprocessor if fitted)

• SERIAL7 -> UART7 (With RTS/CTS)

• SERIAL8 -> UART8

Serial 2, 5 & 7 have RTS/CTS pins, the other UARTs do not have RTS/CTS.

GPS 1 & 2 are on Serial 3 & 4 respectively.

RC Input

RC input is configured on the USART 6 Rx Pin. This pin allows all RC protocols compatible with direct connection to a H7 IC (SBus, CRSF etc), PPM is NOT supported.

USART 6 Tx is available for use with bi directional protocols.

An optional IOMCU can be connected to this serial port, a compatible custom build of the firmware required.

CAN Ports (Light Green Fade)

2 CAN buses are available, each with a built in 120 ohm termination resistor.

I2C (Maroon Fade)

I2C 1 - Internal for BMM150 Compass

I2C 2 - Internal for DPS310 Barometer

I2C 3 - External With internal 2.2k Pull Up

I2C 4 - External With internal 2.2k Pull Up

SPI (Cyan Fade)

SPI 4 is available for use with external sensors alongside a Chip Select and Data Ready pin, compatible custom build of the firmware required.

PWM Output (Blue Fade)

The Stamp supports up to 10 PWM outputs with D-Shot.

The PWM outputs are in 3 groups:

• PWM 1 - 4 in group 1 (Timer 5)

• PWM 5 - 8 in group 2 (Timer 4)

• PWM 9 & 10 in group 3 (Timer 2)

Channels within the same group need to use the same output rate. If any channel in a group uses D-Shot then all channels in the group need to use D-Shot.

BiDirectional DShot available on the first 8 outputs.

A buzzer alarm signal is available on Timer 14.

Analog Inputs (Purple Fade)

The board has two ADC input channels for Voltage (0-3.3v) and Current (0-3.3v) measurement. Settings are dependent on the external hardware used.

Ethernet (Green Fade)

Ethernet is available on 4 output pads and has internal magnetics supporting direct connection to external equipment, no need for a large RJ45 connector

Compass

The H743 Stamp has a built in compass, the BMM150. Due to potential interference the board is usually used with an external I2C or CAN compass as part of a GPS/Compass combination.

USB

USB Signals D+ & D- are available to route to a suitable connector for your project.

Safety Button

Optional, if it is not fitted remove the check from arming mask. To activate short this pad to 3.3v with a momentary push button (Press & Hold)

Power

A regulated 3.3v output is available from the stamp for use with the safety button. WARNING! This is shared with the main IC - Do NOT use for accessories. Keep current draw under 0.1A!

The Stamp requires a stable 5v supply input of at least 1.5A. This directly powers the 5v components and supplies the 3.3v LDOs with power. Typical idle usage is 0.35A @ 5v.

Loading Firmware

The board comes pre-installed with an ArduPilot compatible bootloader, allowing the loading of *.apj firmware files with any ArduPilot compatible ground station.

A built in button can be used to activate DFU Mode by being pressed during power up. The DFU Activate pin is broken out to allow remote mounting of this button if required.