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Can you flash the kk mini with kk2 firmware?

I have a kk mini and would like to change the firmware to one with a failsafe. I couldn't find any firmware specifically for the kk mini. I am using the hk-t6A transmitter so I have no way of adding a failsafe with the radio

Do you know if I can flash the kk2 firmware onto the kk mini, and if not, can you direct me to any firmware with a failsafe for the kk mini?



Hostage Taker of Quads
Staff member
Specifically, the "mini" is a kk2.1.5 board, shrunk. Any kk2.1.x ROM will work -- a Google of "kkmulticopter flash tool" should link you to the software tool that can drive a USBASP for reprogramming.

This won't fix your failsafe issue, however. ALL failsafe functions reside in the RX. The "failsafe" loaded in many flight controllers is code to respond when the receiver goes into it's disconnected state (which is the failsafe, if the RX supports it). If the RX's disconnected state is to continue to send the last signal it's received, the flight control board has now way of knowing the RX has lost contact . . . and off it drifts on a voyage of self discovery :(

In either case, the "Failsafe" in any of the kk2.x boards is "fall out of the sky". As bad as this sounds, it's probably the safest way to go. the longer the props spin without a pilot in command, the farther it will drift, increasing the chance of a damaging crash or outright fly-away. I'd rather have to pick up broken pieces than have no pieces left at all . . . or worse, rush someone to the hospital.

If you'll hook up your RX, removed the props, arm and throttled up, then turned off your radio, whatever the airframe does next is what it will do in the air if the radio link is lost. If you can't live with that, I'm afraid in this case you're better off replacing radio gear than the flight control board.
Thanks for the help. I did the receiver test on the KK mini, and it was capable of recognising if the Tx was not switched on. Does this mean that it will probably completely throttle down if it loses a signal from the Tx?

I am OK with having the failsafe as just dropping out of the sky as I don't intend to fly it with much height or speed, but I don't want it to just fly off, as it is a really important school project, and at least if I crash it I can present the pieces of it and put it down to my own ability as a pilot, rather than problems with the quadcopter itself


Hostage Taker of Quads
Staff member
Probably yes, but why guess or go by my memory? Try it yourself!

- Remove the props
- Power the multirotor and radio
- Arm the multirotor and spin the motors up to idle
- turn off your radio.

What it does next is what it will do when it gets out of range -- if the motors stop, it will fall out of the sky.

. . . and if the project report needs a section on "safety", add this as the test run. (and if it doesn't, this is something easy to bulk it up ;) )
No, it doesn't seem to have one. Now I have got my quadcopter flying I will invest in a better radio, I wanted to get something with expo capability anyway

Thanks for your help, it saved me a lot of time