How to use kakutef4 no aio for 4 servos and rotor

I want to use a Holybro kakute F4 v 2.1 FC (non Aio) to replace the bar or kbar in my flybarless align trex450. I can load arducopter firmware into it and it works in MP with sbus FRsky rx. But how do I connect 3 cyclic servos a tail servo and main rotor motor? My 4 pwm outputs seem to be for motors. Can I remap the ledstrip to a motor or servo? I can’t make any sense of the trad Heli setup wiki. Please help.

That Flight Controller has 4 outputs in 2 timer groups. Motors and servos need to be configured in separate timer groups. I don’t think it will work for that application.
Kakute F4
Up the spec on the Flight Controller.

I am also looking for similar application (TREX250)
The Kakute F4 is moreless designed for quatrocopter. If you want to use the Holybro Kakute the only one is the Kakute H743 Wing. Other comparable good possibility seems to be the all Matek H743 boards. I am more tending to the Matek H743 slim or mini due to the weight.

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Good choices. All kinds of options with those

PWM rate or Dshot, when configured as a normal servo/motor output) are: 1/2, 3/4/5/6, 7/8/9/10, 11/12, and 13 (LED)

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Philip, I thought a little more about your question? Do you have the Holybro kakute F4 v 2.1 FC already? How you fly your Trex450 at the moment?
I am using my Trex250 at the moment with a cnventional Futaba RC system and just a gyro for the tail. In my setup the PWM controlled ESC has an internal govenour. On my transmitter I have set the throttle just to switch with either has 1000 or 1700 µsec PWM. So the rotor is running moreles at constant speed. I don’t fly any acrobatic only more scale like.
With this setup I think it might be possible to use only the 4 PWM outputs of the kakute F4 for the servos and leave the ESC directly connected to the RC receiver.
This is not ideal but maybe a start.
I don’t know how to ad also the Tradi Heli forum to this postings. It might be good to get also information from that people

Thanks for the replies. Here’s the confusion…I used mission planner to change the FC firmware to plane 4.4. now the 4 pwm outputs work for servos but output 3 is disarmed where the throttle would be. I’ve connectioed the GPS to tx and Rx 4 but don’t have a fix yet. Also I don’t know where to connect the compass. Can I use tx and Rx 6 for that? This FC does not have ic2 pads but has rsi and diet pads whatever they are. Seems weird that I can’t put copter firmware on it to use as a trad Heli with servos!

Why can’t you put Tradheli firmware on it? when you go to the mission planner setup page and go to the install firmware tab on the side. You should see the icon for heli. You should just be able to click on it and it will install the heli firmware. Are you getting an error?

This is a bad idea. There are safety features that you would be bypassing by doing this. Most importantly the prearm checks that keep you from starting the motor if the fc detects a problem.

Well progress of a sort! I can disable the compass and use this FC for a plane. When I try to put trad Heli firmware I can get the basic quad copter options but not single rotor.

The obvious problem with trad Heli would be only 3 cyclic outputs and a motor output but no tail servo. Unlessicould temps ledstripfor that.

So there aren’t any H_ Params when you look at the full parameter list? If there aren’t then you are loading the Tradheli firmware

Yeah. This fc just won’t do. Buy one with at least 5 pwm outputs.

Sure it does. They are probably labeled SDA/SCL

I agree fully with you to use a FC with minimum 5 PWM channels. So at the starting point I recommended other FCs.
The idea to bypass the FC was just based to start with existing HW and the experience of a Heli pilot using just a RC system without FC. Yes, in that case we lose the food feature of prearm checks but this is the same as flying without FC as before.
But if Philip wants to fly full featured with any auto mode it is a no go. In such a case the FC must also control the motor.

Will probably need more than 5 as with the configuration he mentions you would need 4 outputs on 1 or a combination of timers for the servo’s.

But, I’m not a Trade Heli guy so perhaps I haven’t considered all.

This Kakute F7 with 6 outputs would work:
The PWM is in 3 groups:

  • PWM 1, 2 and 3 in group1
  • PWM 4 and 5 in group2
  • PWM 6 in group3
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Has anyone used a iflight blitz mini f722 FC with Ardupilot. There does not seem to be a firmware build for it.

Nor will there ever be for any F722. Not enough memory. Just buy an H7 based FC.

If you look to the Matek FCs I recommended in my first posting above you are in a similar price range