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Jun 23, 2012, 11:27 AM
Registered User
Quote:
Originally Posted by Erknie
There is a force trying to accelerate the FC at 9.8M/sec ^2 in the Z axis all the time. It's called gravity. An accelerometer, once calibrated, is far more accurate at figuring what is level than a magnetometer, which can swing wildly with just a change in motor current! A magnetometer is really just used as a compass when you want the copter facing one way all the time for AP or something similar. Not much use for general flying.
Ahh... Okay I get it now. Thanks for the explanation!
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Jun 23, 2012, 11:42 AM
Registered User
I hope hobbyking will make a box for this kk2 board. I don`t like that the board is exposed like this.
Jun 23, 2012, 12:02 PM
Registered User
Akcopter's Avatar
So am i suppose to put up with this 3 month wait or make it myself,i hope kk opensources the hardware quick.....
Last edited by Akcopter; Jun 26, 2012 at 08:40 AM.
Jun 23, 2012, 01:03 PM
Fly, crash, rebuild.
Free enterprise. They underpriced it. Sold out in less than 12 hours. That means it was too cheap. They don't need a buddy code to move these. $9 thrown away by hk in my opinion. I'm grateful but that's not what I would have done. As far as wait time, hk has little influence over their ability to get a commitment at such a low price. You want it cheap, you will wait until it becomes a priority for the manufacturer. Stop the nonsense. Go and fly and take the edge off.
H
Jun 23, 2012, 01:47 PM
Home of A-10 - Farmingdale NY
boiko's Avatar

Low Battery Voltage Alarm


Given KK's statement, how exactly would the low battery voltage alarm be implemented?

"The Battery voltage input is the unpopulated hole to the left of the yellow component..."

Thanks,
-mike-
Jun 23, 2012, 06:57 PM
OpenAeroVTOL developer
HappySundays's Avatar
Quote:
Originally Posted by boiko
Given KK's statement, how exactly would the low battery voltage alarm be implemented?
"The Battery voltage input is the unpopulated hole to the left of the yellow component..."
Thanks,
-mike-
Oh, you just make a connection between the LiPo supply and that hole ( and ground of course). The battery voltage will be divided down on-board so it will be safe. KK Plus did the same thing.
Personally I make up a parallel cable from the ESC's battery connector.
It would have been easier if there had been a more obvious ground connection to pair up with that hole but if you connect from underneath there is a ground point not far away.
Jun 24, 2012, 08:31 AM
Quad Whisperer
Quote:
Originally Posted by er9xuser
Thank you godfather of quads!
I think you are confusing me with this gentleman!

Quote:
Originally Posted by SVentas
Good work ! Very nice!
What about accelerometer? Is it ADXL335 or something better?

IDG650 gyros are no longer in production, but I hope HK has plenty of them .

Ordered one board. I will try to make a custom CopterControl board with these gyros .
It is ADXL335. The engineer at hobbyking told me they had bought plenty of the gyros.
Quote:
Originally Posted by HappySundays
Oh, you just make a connection between the LiPo supply and that hole ( and ground of course). The battery voltage will be divided down on-board so it will be safe. KK Plus did the same thing.
Personally I make up a parallel cable from the ESC's battery connector.
It would have been easier if there had been a more obvious ground connection to pair up with that hole but if you connect from underneath there is a ground point not far away.
Only need to connect a cable from battery+ to this hole. The ground return is through ESC#1's ground wire.
Jun 24, 2012, 09:07 AM
Registered User
Quote:
Originally Posted by kapteinkuk
Only need to connect a cable from battery+ to this hole. The ground return is through ESC#1's ground wire.
Do you smooth the voltage from the battery? I have seen many battery alarms give false reading when the copter is under full throttle, due to voltage drop on the often too skinny cables. I thought a simple RC filter to the battery sensing pin could fix that.
Jun 24, 2012, 02:10 PM
Registered User
Quote:
Originally Posted by Erknie
Do you smooth the voltage from the battery? I have seen many battery alarms give false reading when the copter is under full throttle, due to voltage drop on the often too skinny cables. I thought a simple RC filter to the battery sensing pin could fix that.
battery voltage always drops under load. there is no current (microamps at most) going through this battery-voltage-measuring wire, so there wont be any drop in this wire.
Jun 24, 2012, 02:12 PM
Emress
Quote:
Originally Posted by culexus
I hope hobbyking will make a box for this kk2 board. I don`t like that the board is exposed like this.
there was a post somewhere by someone who made a case for it. ill see if i can find it

Quote:
Do you smooth the voltage from the battery? I have seen many battery alarms give false reading when the copter is under full throttle, due to voltage drop on the often too skinny cables. I thought a simple RC filter to the battery sensing pin could fix that.
id rather my batteries not drop down to 3.3v per cell that the alarm is triggered, so if the voltage drops on load and the alarms goes off, when i land the voltage will stabilize to about 3.5-.6 or so.
Jun 24, 2012, 09:21 PM
Registered User
do we have 4.7 ver for hexa configuration or y6 config?
Jun 24, 2012, 09:25 PM
Registered User
Quote:
Originally Posted by quix-fz
battery voltage always drops under load. there is no current (microamps at most) going through this battery-voltage-measuring wire, so there wont be any drop in this wire.
Voltage drop on the battery-voltage-measuring wire is not the issue, spikes below the alarm threshold are, resulting in false alarms, forcing people to artificially lower the alarm voltage setting, when all it needs is smoothing. You can do it in software, just set it so the alarm doesn't sound unless the voltage has been below the threshold for say several seconds.

Quote:
Originally Posted by bigbro3760
do we have 4.7 ver for hexa configuration or y6 config?
This board uses version 1.0 firmware. Perhaps you are in the wrong thread?
Last edited by Erknie; Jun 24, 2012 at 11:09 PM.
Jun 25, 2012, 03:08 AM
OpenAeroVTOL developer
HappySundays's Avatar
Quote:
Originally Posted by Erknie
Voltage drop on the battery-voltage-measuring wire is not the issue, spikes below the alarm threshold are, resulting in false alarms, forcing people to artificially lower the alarm voltage setting, when all it needs is smoothing. You can do it in software, just set it so the alarm doesn't sound unless the voltage has been below the threshold for say several seconds.
This board uses version 1.0 firmware. Perhaps you are in the wrong thread?
The board has hardware smoothing on the Vbat line and if there is also a bit of hysteresis in the software then there will be no problems with false alarms.
Jun 25, 2012, 05:00 AM
Quad Whisperer
The LVC is only active when battery voltage is below the limit. When it goes above, it stops.
Also it beeps faster the lower the voltage is below the limit.
Jun 25, 2012, 05:45 AM
Went to mow a meadow
frank48's Avatar
My order has gone from backorder to reserved

Frank