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!
Update (27 Sep 2019): There is now a new version Kakute F7 V1.5!
Check out our Flight Controller Buyer’s guide.
Where To Buy?
All-In-One Version (PDB integrated)
- Banggood: http://bit.ly/2LQoWqE
- Amazon: https://amzn.to/2JQb6Te
- GetFPV: http://bit.ly/2nNMYIp
You can get it with the Atlatl V2 VTX as a combo to save a few bucks :)
Non-AIO Version (Best with 4in1 ESC):
- GetFPV – http://bit.ly/2Q8VqPp
- Amazon – https://amzn.to/2oIoLUj
Spec
- 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
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 AIO 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.
Here is the pin-out (wiring) diagram.
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.
Kakute F7 Non-AIO FC
The spec and features are the same as the All-in-One version, except it doesn’t have the large solder pads for power and ESC’s, and the layout is slightly different.
The Kakute F7 board doesn’t have breakout soldering pads for ESC signals, so you would have to use the JST connectors to connect to the ESC’s.
Watch out for the non-square shape and the “extended tab” as it might not fit certain frames with tight spaces.
In my opinion this FC should be used with an 4in1 ESC, for example the Tekko32 4in1.
It can be bought together with the Atlatl HV V2 VTX as a bundle.
The pin-out is similar to the AIO version:
Hardware Bug
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!
ArduPilot Support
You can flash Ardupilot firmware on this flight controller for better GPS features.
Edit History
- July 2018 – Article created for Kakute F7 AIO
- Sept 2018 – Added info about the non-AIO FC
48 comments
What is the I wire/connection on the ESC harness?
me too —what is the “I” not addressed anywhere
Hi Oscar,
Great site and resources. Couldn’t have done half of my builds without it.
I did some mods to my quad last night, and now I notice that I am unable to power the FC from the 4S LiPo battery. I have to plug the USB in in order for the FC to receive power. Has anyone seen this before?
I can plug in the LiPo to power the motors, but I have to physically connect the USB to power the FC (and then everything is powered).
Sounds like the 5V BEC on your FC is fried.
Hi, thanks for this review, good job as always! I am trying to coat my F7 in conformal coating but making sure I don’t ruin anything, I’ve heard you shouldn’t coat over the Barometer, is this true, also if so where is it on the board? Is there anything else I shouldn’t coat besides obviously the boot button and usb port? Any help is much appreciated!
No you shouldn’t coat the baro.
It’s the silver chip next to the F7 chip, with a hole on it.
Hello. Does anyone know what the square grey piece with the number 100 written on it is? Is that an inductor? It is present on both AIO and Non AIO boards. I have seen similar pieces on other FCs, also with either 100 or 150 stamped on it.
Anyway, it somehow bent upward on my board. Don’t ask me how. I guess I am a clutz. I bent it back, but I am not confident at all that its going to stay like that or if it is not already damaged to much. The board powers on over usb. I haven’t tested with battery yet. If this is an inductor or capacitor to clean up the noise in the power, I may still be able to use this FC as I will be pairing it with a dji airunit. The airunit will have a stand alone bec in front of it. I have not had any issues with noise and the airunit previously, it seems to be less susceptible to noise.
Can i use kakute f7 with ardupilot firmware and gps in a align trex 550 helicopter with position hold ,return to home and gps missions?
I dont have many builds under my belt yet…and i am curious why there would be an exposed ‘power bar’?
Is it supposed to be for an easy way to get to Vbat power?
No, it’s just there to reduce resistance, potentially reduces noise in the power as well.
For those of you using or trying to use 32/32k, it seems now that devs are having a change of heart concerning these speeds. The problem is the increased sensitivity associated with 32k. It’s causing all kinds of unnecessary feedback that subsequently creates the need for new filters, so on and so on… Bardwell did a great vid explaining this. After plenty of research I have found that 32k is nothing more than a marketing ploy to sell more boards that is now backfiring. 8k should be more than enough for even the craziest race kwad. I guarantee you cant tell the difference between the two, unless it’s a placebic reaction.
I’m concerned that the non-aio versions gets all its power from the connecter to the Tekko32 4in1 ESC. Do you think that fine gauge wire is enough to support a 1W VTX , radio, camera and GPS? Is there another pin that can be used to provide Vbat to the FC? Or is this unnecessary? Don’t want to find out the hard way, these boards are pricey.
The wire it comes with should be fine to power both FC and VTX.
So with the softmounted gyro do you still bother to softmount the flight controller?
No need.
Does Kakute F7 support iNav ?
Oscar will the Kakute f7 and the Tekko 32 4in1 esc fit in the flip mode frame?
should be doable with the right standoffs
The F7 chip gets hotter than the F4? I have one that is getting really hot, if I leave my thinger on it after 6 seconds it starts to hurt a little… Is that normal for F7?
Well my board is detective, the OSD doesn’t word and it is getting hot =(
The following is directly from the manual of the F7 AIO, l”If your camera uses digital control, solder the camera ‘TX’ wire to pad ‘R3’ on the Kakute F7 AIO. Solder the camera ‘RX’ wire to pad ‘T3’ on the Kakute F7 AIO”…. The instructions say to place to TX to R3 and RX to T3, are these instructions backwards, or are they correct?
they are correct.
Hello,
my F7 gets very hot… Do you have the same problem?
I cannot touch the CPU directly, but I can sense the heat when coming close. I estimate 60-80°C
Regards,
Hendrik
I wouldn’t worry about it, it will get cool down in flight. Just fly it.
The manual I have says to use M5 for analogue camera control (im using a predator v3), but you seem to have used the CAM pin, which way is correct?
See section “Hardware Bug”
I thought the “I” pin was the NC-no connection pin?
I don’t see any support for this F7 board with Inav. Is that in the works?
Does anyone know what the ‘I” pin is on the F7 plug? I’m wondering if it the current pin to the 4in1. Any help would be great.
Thanks.
Yes, I is current sensor.
I am wiring the F7 to Aikon32 4 in 1 ESC and i’ve matched the current pin on the ESC to the “I” pin on the F7 but i’m not getting any current. I do have the port and the ESC setting turn on in betaflight. Any thoughts on why I’m not getting current?
The pin “I” is not part of the ESC telemetry, it’s just a current sensor reading. You need to select “Onboard ADC” in power setting tab in Betaflight for current sensor.
Suggest a WARNING be provided in your post that ‘reversing an ARDUPILOT’ flash is difficult and your Kakute F7 may not easily go into DFU mode. Thanks for the post. Very informative. BUT ….. do you have any idea how to flash from Ardupilot back to Betaflight on the Kakute F7?
This FC works with ArduPilot. I think it is one of the lowest cost flight controllers you can get for a photography drone.
It would be good to see his FC reviewed by someone who is going to load this up with sensors and gear and use all 6 UARTS. How well does GPS position and altitude hold work?
My guess is that for racing you are not going to notice the difference between this and an F4 or F3.
Hi.
Do you know if the hardware bug has been solved with BF 3.4.0 or 3.5.0 ??
Thanks in advance
You can’t solve a hardware bug by software
I know.
I intend if the new BF fw has the needed resources remap to work correctly inside it
What magical Fairy Dust does the Kakute F7 AIO require to actually get the GPS to be recognized by BetaFlight?
I have tried multiple UART connections, reversing the RX/TX on each, and separate M8N GPS/Compass units.
Same results…
I have gone off and ordered a Pixhack V3 just because tired of dicking with poorly document boards like this.
Any ideas – Been through every Betaflight manual and video I can find.
please see my GPS guide.
For me GPS was recognised straightaway, once I’d changed protocol to ublox.
A few pointers for anyone with a problem: –
Make sure you cross rx/tx over
Only works with a battery connected, not on USB power
Change protocol to ublox
I am also unable to run at 32/32 without pegging the CPU at 100%. I can get to about 30% CPU running 32/16 with ACC and barometer off. Have tried re-flashing and erasing all settings, turning off all sensors but it just pegs at 100% at 32/32 no matter what. Weird. Will email holybro.
I’ve just installed a kakute F7 and have the same on BF 3.5.1 32/16 = 34% cpu usage, 32/32 = 100% disappointing was hoping to finally try this and expected it to run it with plenty of head room.
I bought the Kakute F7 and cant seem to run 32/32k with Dshot 1200.
If I try without overclocking, my CPU load goes straight to 100% with the same settings you are running.
Did you overclock the CPU to 240MHZ to achive 54% at 32/32k?
No I didn’t overclock it. Even at 54% CPU load, it’s still a bit too high, maybe stay at 16K for now until they optimize it a bit more :)
54% CPU isn’t too high
I bought the Kakute F7 and cant seem to run 32/32k with Dshot 1200.
If I try without overclocking, my CPU load goes straight to 100% with the same settings you are running.
Did you overclock the CPU to 240MHZ to achive 54% at 32/32k?
ON my FPVmodel F7 i had to disable blackbox logging completely. Then it went down to 41% overclocked at 32/32k. AC and other sensors disabled as well. I think i also had to turn on Dshot burst as well. That helps with CPU but not sure if its supported on all flight controllers.
It’s interesting how flight controllers are picking up more and more powerful processors. I guess, H7 FCs will come soon as well.