Holybro Kakute H7 V2¶
above image and some content courtesy of Holybro
Where to Buy¶
Available from many retailers including Holybro
Specifications¶
Processor
STM32H743 32-bit processor
AT7456E OSD
128 MByte flash for logging
Sensors
BMI270 IMU (accel and gyro only, no compass)
BMP280 barometer
Power
2S - 8S Lipo input voltage with voltage monitoring
9V, 1.5A BEC for powering Video Transmitter
Interfaces
9x PWM outputs (9th pwm output is for NeoPixel LED string via the LED pad)
1x RC input
6x UARTs/serial for GPS and other peripherals
1x I2C port for external compass
USB-C port
Switchable VTX power
All UARTS support hardware inversion. SBUS, SmartPort, and other inverted protocols work on any UART without “uninvert hack”
External current monitor input
Pinout¶
Pin |
Function |
---|---|
VTX+ |
9V for HD System or other VTX, by default ON/OFF is controlled by RELAY2. See Relay Switch Can be controlled by RELAY2 |
SDA, SCL |
I2C connection (for peripherals) |
5v |
5v output (1.5A max) |
3v3 |
3.3v output (0.25A max) |
Vi |
Video input from FPV camera |
Vo |
Video output to video transmitter |
CAM |
To camera OSD control |
G or GND |
Ground |
RSI |
Analog RSSI (0-3.3v) input from receiver |
R3, T3 |
UART3 RX and TX |
R4, T4 |
UART4 RX and TX |
R6, T6 |
UART6 RX and TX (UART6 RX is also located in the GH plug) |
LED |
WS2182 addressable LED signal wire |
Z- |
Piezo buzzer negative leg |
ESC Port 1¶
Pin |
Function |
---|---|
B+ |
Battery positive voltage (2S-8S) |
R7 |
UART7 RX |
GND |
Ground |
CURRENT |
CURRENT |
M1 |
Motor signal output 1 |
M2 |
Motor signal output 2 |
M3 |
Motor signal output 3 |
M4 |
Motor signal output 4 |
ESC Port 2¶
Pin |
Function |
---|---|
B+ |
Battery positive voltage (2S-8S) |
R7 |
UART7 RX |
GND |
Ground |
CURRENT |
CURRENT |
M5 |
Motor signal output 5 |
M6 |
Motor signal output 6 |
M7 |
Motor signal output 7 |
M8 |
Motor signal output 8 |
VTX Port¶
Pin |
Function |
---|---|
Vtx+ |
9V for HD System or other VTX, by default ON/OFF is controlled by RELAY2. See Relay Switch |
G |
Ground |
T1 |
UART1 TX |
R1 |
UART1 RX |
G |
Ground |
R6 |
UART6 RX |
UART Mapping¶
The UARTs are marked Rn and Tn in the above pinouts. The Rn pin is the receive pin for UARTn. The Tn pin is the transmit pin for UARTn.
SERIAL0 -> USB
SERIAL1 -> UART1 (Telem1) DMA-enabled
SERIAL2 -> not available externally, internally connected to currently unsupported BT-LE module
SERIAL3 -> UART3 (SmartAudio VTX protocol by default)
SERIAL4 -> UART4 (GPS) DMA-enabled
SERIAL5 -> not available
SERIAL6 -> UART6 (Setup for serial RX Protocol SBUS by default) DMA-enabled
SERIAL7 -> UART7 (RX7 only available, normally used for ESC telemetry protocol by default)
The SERIAL7 port (UART7) is normally for ESC telemetry, and has an R7 pin on both of the ESC connectors.
Any UART may be re-tasked by changing its protocol parameter.
Copter Default Frame Type¶
For Copter firmware the FRAME_TYPE is already defaulted to type “12” (BetaFlight X) allowing existing BetaFlight configurations with ESCs attached to have the correct motor ordering without changes to the FRAME_TYPE and FRAME_CLASS parameters or ESC wiring.
RC Input¶
RC input is configured on the R6 (UART6_RX) pin. It supports all RC protocols except PPM. See Radio Control Systems for details for a specific RC system. SERIAL6_PROTOCOL is set to “23”, by default, to enable this.
SBUS/DSM/SRXL connects to the R6 pin.
FPort requires connection to T6 and SERIAL6_OPTIONS be set to “7”.
CRSF also requires a T6 connection, in addition to R6, and automatically provides telemetry. Set SERIAL6_OPTIONS to “0”.
SRXL2 requires a connecton to T6 and automatically provides telemetry. Set SERIAL6_OPTIONS to “4”.
Any UART can be used for RC system connections in ArduPilot also, and is compatible with all protocols except PPM. See Radio Control Systems for details.
FrSky Telemetry¶
FrSky Telemetry is supported using the Tx pin of any UART. You need to set the following parameters to enable support for FrSky S.PORT (example shows SERIAL2).
OSD Support¶
The KakuteH7 supports OSD using OSD_TYPE 1 (MAX7456 driver). The defaults are also setup to allow DJI Goggle OSD support on UART1.
PWM Output¶
The KakuteH7 supports up to 8 PWM outputs. Outputs are available via two JST-SH connectors. All 8 outputs support DShot and bi-directional DShot, as well as all PWM types.
The PWM is in 3 groups:
PWM 1, 2 in group1
PWM 3, 4 in group2
PWM 5, 6 in group3
PWM 7, 8 in group4
PWM 9 (LED) in group5
Channels within the same group need to use the same output rate, whether PWM or Dshot. If any channel in a group uses DShot then all channels in the group need to use DShot.
Note
for users migrating from BetaflightX quads, the first four outputs M1-M4 have been configured for use with existing motor wiring using these default parameters:
FRAME_CLASS = 1 (Quad)
FRAME_TYPE = 12 (BetaFlightX)
LED Output¶
The LED output is configured by default to support NeoPixel LED strings.
Battery Monitoring¶
The board has a built-in voltage sensor via the B+ pin, but no internal current sensor. An external current sensor can be connected to the CUR pin. Default parameters for both internal voltage and external current monitoring are set by default to the below for use with any Holybro Tekko32 F4 4in1 ESC.
The correct battery setting parameters are:
BATT_VOLT_MULT 10.1
BATT_AMP_PERVLT varies depending on external current sensor
Compass¶
The KakuteH7 V2 does not have a built-in compass, however you can attach an external compass using I2C on the SDA and SCL pads.
Firmware¶
Firmware for this board can be found here in sub-folders labeled “KakuteH7v2”.
Loading Firmware¶
Initial firmware load can be done with DFU by plugging in USB with the bootloader button pressed. Then you should load the “with_bl.hex” firmware, using your favourite DFU loading tool.
Once the initial firmware is loaded you can update the firmware using any ArduPilot ground station software. Later updates should be done with the *.apj firmware files.