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Old Jun 05, 2010, 04:42 PM
Quad Whisperer
Joined Jul 2008
942 Posts
Quote:
Originally Posted by uzykc View Post
can anyone please explain to me how you are reading in the signal from the your Futaba 6EX receiver into your uC? I am having difficulties trying to read the PWM signals from the receiver into my PIC uC. I thought about averaging the PWM signal and then calibrating. Please help!
The output from the RX is called a PPM signal, not PWM. (EDIT: I was wrong here, it is called PWM, the text below is corrected)

In my design there is a 16bit counter running at 1MHz.
Each channel is connected to a own pin and generates its own pin change interrupt, which in turn has its own interrupt code.

The code does as follows:

If it is a rising edge (start of the PWM signal): Store the counter value in RAM and exit.

If it is a falling edge (end of PWM signal): Subtract the stored counter value from the present counter value and negate (make it positive) the result if negative. Now you have the PWM value in microseconds.

This works with non overlapping and overlapping (like in the never futabas) channels.
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Old Jun 05, 2010, 06:25 PM
Registered User
Ourense, Spain
Joined Nov 2005
48 Posts
Quote:
Originally Posted by kapteinkuk View Post
Congrats on a flying quad!
Thanks Kapteinkuk, more than 70% of this success is yours!!
Another video, this time outdoors in my club field.
Zotfidjy: Vuelo exterior Quadcopter ( Araxiñas) (3 min 53 sec)


It fly very stable and easy. Im going to make some test with onboard video.
Also im thinking of installing a Fma copilot, and a Ardupilot, for fpv and aerial photography.
Thanks a lot.
Telmo
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Old Jun 05, 2010, 11:46 PM
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pabmadi's Avatar
Joined Feb 2009
184 Posts
Quote:
Originally Posted by Jakub J View Post
Yes, I prefer slanted props
GWS 10x4.7 are almost indestructible...

Jakub
How is configurer the angles to use standar prop ??
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Old Jun 05, 2010, 11:54 PM
Jakub J's Avatar
Krakow/POLAND
Joined Dec 2009
1,737 Posts
Quote:
Originally Posted by pabmadi View Post
How is configurer the angles to use standar prop ??

CW motors are slanted by about 9 degrees to the right.

Jakub
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Old Jun 06, 2010, 12:39 AM
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bob4432's Avatar
United States, AZ
Joined May 2010
1,820 Posts
Quote:
Originally Posted by Jakub J View Post
CW motors are slanted by about 9 degrees to the right.

Jakub
i have seen amounts from 6-10 degrees - is there a known amount? or i guess constant? do you figure it out by trial and error? in theory i would like to be able to use the expanded options of using all "normal" props and would rather mount the motors at a slant (i believe the 2 side motors in a "+" configuration, correct?), but does anybody know the exact amount of slant?
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Old Jun 06, 2010, 01:19 AM
Jakub J's Avatar
Krakow/POLAND
Joined Dec 2009
1,737 Posts
Quote:
Originally Posted by bob4432 View Post
i have seen amounts from 6-10 degrees - is there a known amount? or i guess constant? do you figure it out by trial and error? in theory i would like to be able to use the expanded options of using all "normal" props and would rather mount the motors at a slant (i believe the 2 side motors in a "+" configuration, correct?), but does anybody know the exact amount of slant?
Yes, trial and error metod

It is <> 9 degrees to right. If you quad start rotate CCW then
you should rotate slanted motors to left (less slant). If quad going
CW you should rotate motors to right to the moment when quad
will not rotate. You can trim a little using Tx, but quad should be
as stable as possible before this.

Jakub
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Old Jun 06, 2010, 02:12 PM
Why walking when you can fly ?
fmelle's Avatar
France, IdF, Clamart
Joined Mar 2007
109 Posts
Little question before powering on

Hello all and thank-you KK for your very nice and affordable quad project.

I finished all the wiring this evening and before powering on, I have a question regarding the ESC. I assume that all the ESC but one have the red wire not connected ? This way I uses only one BEC avoiding any problem ...

I use 420RcPilot Through hole PCB and I am building a quad.

Does anyone fly with all BEC providing 5V to the board ?

Thank-you for reading and I hope for answering
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Old Jun 06, 2010, 02:28 PM
Jakub J's Avatar
Krakow/POLAND
Joined Dec 2009
1,737 Posts
Quote:
Originally Posted by fmelle View Post
Hello all and thank-you KK for your very nice and affordable quad project.

I finished all the wiring this evening and before powering on, I have a question regarding the ESC. I assume that all the ESC but one have the red wire not connected ? This way I uses only one BEC avoiding any problem ...

I use 420RcPilot Through hole PCB and I am building a quad.

Does anyone fly with all BEC providing 5V to the board ?

Thank-you for reading and I hope for answering
Yes, me

In one my quad and in sexy I have all BEC connected
(TowerPro 12A). In bigger quad only one BEC (Turnigy 10A).
No visible different for me...

Probably the best solution is use separate LiPoli with
voltage regulator to power board from clean power source...

Jakub
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Old Jun 06, 2010, 02:36 PM
Registered User
POLAND
Joined May 2010
23 Posts
Hi
(Sorry for my English, I translated in google)

I built quadrokopter by the Kapteinkuk project.
I used ATMEGA48, PCB V5, Emax 2822, HK SS 15-18A ESC , soft V4.3.
transmitter is HK6X.
in the new gyro is HK401B pots not 10k only 20k,and such I used.

I have a big problem.
Four engines are not moving at the same time.
The difference comes to seven seconds.
All four ESC set throttle range.
If connect all four ESC to one channel - THR in the RX ,engine starts at the same time.
What could be wrong.

Quadcopter - engines test (0 min 18 sec)
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Old Jun 06, 2010, 03:33 PM
Quad Whisperer
Joined Jul 2008
942 Posts
Strange...
Describe the LED behavior when powering up.

Does it react to the aileron and elevator stick?
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Old Jun 06, 2010, 03:41 PM
Quad Whisperer
Joined Jul 2008
942 Posts
Quote:
Originally Posted by fmelle View Post
Hello all and thank-you KK for your very nice and affordable quad project.

I finished all the wiring this evening and before powering on, I have a question regarding the ESC. I assume that all the ESC but one have the red wire not connected ? This way I uses only one BEC avoiding any problem ...

I use 420RcPilot Through hole PCB and I am building a quad.

Does anyone fly with all BEC providing 5V to the board ?

Thank-you for reading and I hope for answering
Thanks

I leave all the BEC's connected. Parallelling linear voltage regulators is no problem as they does only source current. They can not sink current from another regulator. In case of uneven voltage output, all but the highest regulator turns off.

The "BEC fighting each others" is an urban myth that does not want to die.

Many ESC's uses 2 parallelled regulators.
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Old Jun 06, 2010, 04:05 PM
Why walking when you can fly ?
fmelle's Avatar
France, IdF, Clamart
Joined Mar 2007
109 Posts
Thank-you for your quick answer !

So I will plug all 4 ESC as normal and check how the quad behave

Good week for all you fans of KK work !

Quote:
Originally Posted by kapteinkuk View Post
Thanks

I leave all the BEC's connected. Parallelling linear voltage regulators is no problem as they does only source current. They can not sink current from another regulator. In case of uneven voltage output, all but the highest regulator turns off.

The "BEC fighting each others" is an urban myth that does not want to die.

Many ESC's uses 2 parallelled regulators.
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Old Jun 06, 2010, 04:29 PM
Registered User
POLAND
Joined May 2010
23 Posts
Quote:
Originally Posted by kapteinkuk View Post
Strange...
Describe the LED behavior when powering up.

Does it react to the aileron and elevator stick?
When powering up LED will blink for a moment, then lights up constantly.
Aileron and elevator stick working properly:
Stick UP -> M4-up and M1-down
Stick Down -> M1-up and M4 down
Stick Left -> M3-up and M2-down
Stick Right -> M2-up and M3-down

The response to the gyro sensor to good.
After write ClockTest LED on-off every 55sec
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Last edited by darek53; Jun 06, 2010 at 04:37 PM.
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Old Jun 06, 2010, 04:56 PM
Quad Whisperer
Joined Jul 2008
942 Posts
Have you the possibility to measure the pulse width from the M1-4 outputs?

If you swap the ESC's around, does the delay follow the ESC?
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Old Jun 06, 2010, 05:55 PM
That tree again!!!!
thanhTran's Avatar
Germantown, MD, US
Joined Sep 2004
6,642 Posts
Quote:
Originally Posted by darek53 View Post
...
I have a big problem.
Four engines are not moving at the same time.
The difference comes to seven seconds.
All four ESC set throttle range.
If connect all four ESC to one channel - THR in the RX ,engine starts at the same time.
What could be wrong.

http://www.youtube.com/watch?v=Am8qLqRY11Q
Have you tried calibrating throttle from the quad controller (using yaw gain)?
I've had seen something similar: if I calibrate the ESC's by connecting them all the throttle directly, they are match. Then when I plug the ESC's to the quad controller, I found that I had to calibrate again because all 4 motors don't start at the same time. After calibration, everything works. I didn't investigate further, but it seems to work.
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