The code comes from early versions, so no arming/disarming or other bits he has since added.
…
I would recommend the following set-up procedure if you wish to try the software:
Remove props.
Set 50% (note CCW is always 0) gyro gains to check/Set gyro Reversing (nb different setup).
Check for any wrong behaviour or motor-spasms
Set low (say 10% max 20%) gyro gain settings and fit props.
If all is OK, increase gyro gains as required.
And lastly, it goes without saying - YOU TRY THIS SOFTWARE AT YOUR OWN RISK !!
Now onto the actual software:
There are differences - well there would be wouldn't there !
Read the info at the top of the XXcontrol.c file.
Gyro reversing is different.
Gain pots are always full CCW = 0 (apart from those pots which are back-to-front)
Adjustable ESC-rate: Specify an ESC rate up to 400Hz.
The ESC output rate timing code can be removed (just remark the #define ESC_RATE line) so it simply outputs at max rate. For me this was 400Hz into Hobbywing 18A ESC and it seemed OK.
For Tri-copters, a rate must be set so the controller can work out a suitable rate for the Yaw servo.
(с) https://www.rcgroups.com/forums/showpost.php?p=16318680&postcount=6836
I won't be pursuing this line of development myself, but as a starter for those who do, here are the rules - as I understand - which they need to consider for the schematic:
The gain pots and gyro outputs must go to pins ADC0→7
The RxSignals need to use PinD2 (INT0), PinD3 (INT1) and then 2 more pins which need to be from different Ports (but one can be on PortD)
For the software:
Check/change timers/timings
Ensure variables do not overflow due to them holding larger numbers (nb no floating point vars used)
(с) https://www.rcgroups.com/forums/showthread.php?1324621-XXcontroller-software-for-KKmulticopter