Spoiler: the Kakute F7 AIO flight controller is pretty sweet! With Betaflight performance of F7 FC’s continues to improve, it’s safe to say that F4 is no longer the only option when it comes to choosing your next FC!
Check out our Flight Controller Buyer’s guide.
Where To Buy?
You can get it with the Atlatl V2 VTX as a combo to save a few bucks :)
- Target: KTF7 (Kakute F7)
- MCU (Processor): STM32F745
- Soft-mounted IMU (Gyro): ICM20689
- Input Voltage: 2S-6S
- BEC: 5V/2A, 3.3V/0.2A
- 6 UART’s
- 6 motor outputs allows for hexacopter configuration
- Built-in Current Sensor (up to 130A)
- Onboard BMP280 Baro Sensor
- Micro SD card slot for blackbox recording
- Support Betaflight OSD
- Dimension: 35x48x7mm
- Weight: 11g
Here is the pin-out (wiring) diagram.
Advantages of F7
No Inversion Required!
When I was soldering the board, I couldn’t find any info about SBUS and Smartport pads… Then I remember this is an F7, it doesn’t care about inverted signals!
You can Just connect SBUS and Smartport to any UART and it just works! Having used F4 for so long, I forgot how easy F3 and F7 is!
Low CPU load
F7 is a more capable processor than F3 and F4. With continuous optimization in Betaflight firmware, it will only get better. As for right now (BF3.4), here is the CPU usage running different gyro sampling rate and looptime. (With Dynamic filter, Airmode, Anti-Gravity enabled, ACC disabled)
- 8K/8K – 2% CPU load
- 16K/16K – 7% CPU load
- 32K/16K – 19% CPU load
- 32K/32K – 54% CPU load
Closer Look at the Kakute F7 FC
The Gyro is soft mounted, connected to the board with a flexible ribbon cable. The height of the FC including the Gyro is about 7mm.
The metal bar on the top is connected to the LiPo positive, so make sure you don’t accidentally short it :)
No ESC signal ground on this FC, but there are dedicated ESC telemetry pads at each corner.
Just like other Kakute boards, the Kakute F7 doesn’t support PPM and PWM receivers. If you insist on using these receivers, you can get a PPM to SBUS converter, or PWM to SBUS converter for this board.
I like the Kakute FC series, but the long shape is not going to fit in certain frames. For most freestyle frames it shouldn’t be a problem.
There are 6 UART’s, more than enough for a racing drone, even long range GPS platform.
There are also an onboard BMP280 Barometer and i2c port for GPS module, which are great for GPS applications like iNav.
After using the Rotor Riot Control FC, I really like having the soft mounted gyro protected inside a plastic case. You don’t have to worry about running wires on top which might touch the gyro. I think Holybro should consider something like this.
There is a hardware design flaw in this FC. For me, motor 3 and 4 didn’t work with DShot out of the box. Though all the motors outputs worked with Multishot (don’t forget to calibrate the ESC’s). Multiple users reported the same issue.
There is a work around though. If you don’t want to run Multishot, just DShot, you can simply disable camera control in CLI.
resource CAMERA_CONTROL 1 none save
You can still use one of the spare motor outputs (5 or 6) for camera control if you want. There is a 220 ohm resistor connected to these pads already so you might not need extra resistors. To do so you can enter the following commands in CLI:
resource MOTOR 5 none resource CAMERA_CONTROL C09 set camera_control_key_delay = 125 save
Holybro announced that they will disable camera control feature on all the Kakute F7 boards from now on to support DShot. This bug is only likely to be fixed after Betaflight 3.4.0.
Flight Videos and Follow Up
Despite the hardware bug (not a problem at all if you don’t use camera control), I still like it more than the Kakute F4 – it has more UART’s, no need for signal inversion hacks, and it has 6 motor outputs.
I have been flying this board in my Flipmode frame for a few days now, it’s been solid!