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HK KK 2.1.5 questions

mwm

Junior Member
#1
I'm doing my first DYI build, based on the AnyCopter, and chose (based on everyone saying it's the board to use for your first build) the HK KK 2.1.5 flight controller. I've run into two minor issues (so far):

1) The fpvcentral review of the 2.1 board says " KK now supports plugging in a high-power LED right onto the board for easily-visible flight mode display". To me, that means showing me whether or not auto-leveling is on, however, I can't find any other mention or instructions for this. Do they just mean the LED will go on when you arm it? Or are they completely lost?

2) I've connected the voltage sensor, but it reads well over a volt higher than anything else I use to read the battery power. I was wondering if there was any way to adjust this, or do I just have to compensate when I set up the alarm value?

Thanks,
Mike
 

xuzme720

Dedicated foam bender
Mentor
#2
The LED is activated when the buzzer goes off, as in beeps or voltage alarm. It's meant to provide a visual cue along with the audible one from the buzzer. You need a "y" harness to plug both the LED and the buzzer in though.

I thought there was a way to adjust the reading, but I might be thinking of a different board. I'll see if I can find anything..
 
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trigger

Senior Member
#3
I'm pretty sure there is a way to adjust the voltage reading with Steveis firmware.
I don't know about the stock one, never used it.
Upgrading to Steveis is highly recommended anyway.
 

gizmatron

Junior Member
#4
with both stevis and RC911 firmware you measure your battery with a voltmeter then change the offset for the voltage so it matches the multimeter reading.. easy.. and yes the led just flashes when the buzzer sounds.. on mode changes in mid air via the aux channel or it flashes faster and faster once you reach your preset voltage warning level.
 

Balu

Moderator
Staff member
Admin
Moderator
#5
I just noticed that I did not use the KK2 voltage alarm yet, since i have telemetry on my Taranis. You just need to split the power from the battery into a smaller connector and connect it to the port?
 

DDSFlyer

Senior Member
#6
Yes a JST connector works well. If you have the KK2.1 be careful not to reverse polarity on the JST connector. They have been proven to make the KK boards go Poof! I ended up snipping the (-) negative terminal off so that I don't do that.
 

pweed

Junior Member
#7
connecting voltage monitor on KK 2.1.5

Trying to figure out how / where to connect the voltage monitor jumper documented on page 2 here:

http://www.hobbyking.com/hobbyking/store/uploads/672089481X667872X37.pdf

I spent about 30 minutes chatting with the online support at Hobbyking and I don't think they really knew what I was asking about for awhile. Finally, he told me to connect to the balance connector on my battery (3S 40C 2200mah)...

Is this the correct recommendation and just to be sure, would I basically need a female end of one of these:

http://www.hobbyking.com/hobbyking/..._Male_Female_40P_200mm_Wire_Jumper_Cable.html

to a female JST-XH?

Thanks for any advice you can offer, I'm having a very hard time finding details about this part of the configuration!
 

xuzme720

Dedicated foam bender
Mentor
#8
Actually, you can go with that male to female and plug into the positive side of the balance connector to the positive pin on the board. Only the single lead is needed. Snip off the negative voltage monitoring pin on the board as you won't need that pin and it's a potential board frying point if voltage is ever applied to it. You already have a ground from the ESC's or BEC so you only need to connect positive from the battery for the board to read voltage.
A more secure method is to add in a pin connector to the positive lead you plug the battery into (or an extra pad if you are using a distribution board) and attach that to the pin on the KK2 board
 

Craftydan

Hostage Taker of Quads
Staff member
Moderator
Mentor
#9
You could just use one of those wires -- no need for the JST-XH plug. Plug the male end into the highest pin on the balance connector (farthest from the black wire), and the female end onto the + side of the KK2 vref pin . . .

. . . but I'd go ahead and clip the "-" pin off that Vref header on the board -- you don't need it (the board gets the same ground through the ESCs), and it's been notorious on the kk2.0 and 2.1 boards for frying the board. They *say* they've put in reverse polarity protection . . . but I don't trust 'em. it's just so easy to clip it off and then only route one wire.
 

mwm

Junior Member
#10
Connecting to the balance lead is easiest, and hence a common practice for getting power to things like FPV systems and gimbals as well as battery monitors. Other alternatives are to splice into either lead. I've done that using a T connector, and once when I knew I was going to need it added a monitor lead when I swapped the discharge lead connector on the battery to match the one on my quad.
 

pweed

Junior Member
#11
Nice. Thanks gang, much appreciated!

I too am nervous about the reverse polarity "protection" so it is probably a good idea to clip that pin!

Thanks again!
 

Balu

Moderator
Staff member
Admin
Moderator
#12
Hm. So the KK board just reads the voltage from one cell of the LiPo and not the whole pack?

I thought I had to have the common plus connected there and not just one cell as from the balance plug?
 

Cyberdactyl

Misfit Multirotor Monkey
#13
No, the KK2 reads the whole pack. The drawback to the KK2 voltage setpoint buzzer is just that. It fails to 'see' a low cell. The other negative using it is if you set it for a 3S battery, i.e., somewhere around 10.6V and forget to reset it for a 4S battery. You could easily have your MR drop out of the sky.

On the plus side, you don't have to remember to attach a low voltage buzzer, which DOES read individual cells and buzzes when one reaches the setpoint.
 

xuzme720

Dedicated foam bender
Mentor
#14
Balu, by pulling the voltage off the last wire on the balance plug, you are looking at the whole pack. It's because of how the balance leads are wired and why you can check either individual cells or adjacent cells. I don't want to hijack so if you or anyone else needs more info, let me know.
 

xuzme720

Dedicated foam bender
Mentor
#16
That's exactly right, and good info for anyone wondering how those balance plugs work. For larger cells, the middle connections continue as shown here and the only the outside connections are sent to the discharge leads. So, for a 6S pack, balance leads come off the bridges between adjacent cells; 1-2, 2-3, 3-4, 4-5, 5-6. Also off of ground on cell 1 and positive on cell 6.
Hopefully that makes sense and hasn't made it more confusing... :D
 
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