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3D RoboticsPermalink Reply by Chris Anderson on March 2, 2013 at 5:22pm

How are you powering the board? If you're using the Power Module, you must have a BEC/ESC on the output side to power the servos. the JP1 jumper should be off in that case. 

Permalink Reply by Ray on March 2, 2013 at 6:14pm

If i plug a BEC into the output side of the board, where do I plug it into? Just an open port? If I use a BEC, I HAVE to remove the jumper you refer to?  I do have this power module...how is it supposed to plug into the board? Is that a better option? 

Thanks for the help!

 

Permalink Reply by Anthony Sive on March 2, 2013 at 8:15pm

Hi Ray,

For Power:

Plug the power cable into the PM port on the APM2.5 as shown in the diagram below.

 

Also have a look at this link http://code.google.com/p/arducopter/wiki/AC2_Current

If you connect your ESC on output channel 8 it should also power the output side of the APM.  Remove jumper J1 to ensure the input side and output side are not interconnected.  Otherwise connect a BEC to the +ve and -ve terminals at any point along the output side.

Getting your servos to move:

The latest firmware v2.9.1 for the APM has a safety feature to ensure that you "arm" the APM before flying.  To arm you move the throttle down and fully to the right and hold it there.  In Mission Planner on the Heads-up display you will see the word ARM come up and the red LED on the APM will stop flashing and go to solid on.  Now the servos will move.

Read through this part of the manual http://code.google.com/p/arducopter/wiki/TradHeli_Configuration

Hope that helps.

Permalink Reply by Ray on March 2, 2013 at 8:26pm

Thanks, that helped alot. I went ahead and installed the jumper and I am using a BEC feeding 5.2 volts to the servo out side of the board. Seems to be working fine. This should be sufficient to feed everything correct?

 When i go to do the swash plate setup now, everything works. When I click the "manual" button to do the swash setup, the servos are very jittery! Once back in to normal mode they stop and are fine.

 I appreciate the help.

Permalink Reply by Ray on March 3, 2013 at 1:59pm

Ok, ive followed the setup, everything seems to be coming along fine. Now the PID. WHen I power up normaly like im going to fly, and arm, the servos are very jittery, and once in awhile they will just move up and then down very rapidly, like a nervous twitch,, LOL for lack of a better explination. Im sure its one of the pids settings is high, but which one? Im using align 610 servos.

DeveloperPermalink Reply by Randy on March 3, 2013 at 11:03pm

Ray,

     It's hard to be sure without seeing the logs but if you're using a futaba tx/rx with 8 or more channels then you should upgrade to the latest ppm encoder by following the instructions here.

Permalink Reply by Ray on March 4, 2013 at 7:04am

Thanks for the reply. No im using a Spektrum DX8 with a AR9300 reciever. This is a 600 size electric heli. I got it to town down some, using the rates both roll and pitch, then brought down the stab settings as well. But it is still jittery. Acts like what you would find on other systems when you use the wrong frequency on the servos.

DeveloperPermalink Reply by Randy on March 4, 2013 at 7:46am

Ray,

     You can adjust the update rate to the servos by changing the RC_SPEED parameter.  It defaults to 125 for helictopers and 490hz for multicopters.  Maybe you could try reducing it further by finding and changing it in the Adv Param List of the mission planner.

Permalink Reply by Ray on March 4, 2013 at 8:09am

Thanks Randy, Ill give that a try tonight when I get home from work..

   Is the '125' the frequency? If so that may not be high enough for digital servos. Looking at the specs for my servos it is 200 mhz. That might just fix it. Everything else seems to be working well so far. Thanks for the great help.

DeveloperPermalink Reply by Randy on March 4, 2013 at 8:15am

Yes, that's the frequency in hz.  It can go as high as 490hz or as low as 50hz.

no troubles.

DeveloperPermalink Reply by R_Lefebvre on March 4, 2013 at 8:17am

Ray, are you indoors with the GPS connected when this jitter is happening?

Try disconnecting the GPS and see if it goes away.

Also note that the way you have your power system setup, using a single BEC to power the servos as well as the APM, you could have brown-outs on the APM.  The servos can demand too much power, drag down the voltage, and the APM will go down, which means you crash.

You can get away with this on a 450 with tiny servos, but I really don't recommend it for anything larger.  There's a good discussion about this here:

http://www.diydrones.com/forum/topics/helicopter-avionics-power-supply

Also, the power rail on the output rail of the APM is not rated to carry the amperage of 4 full-size digital servos.  You really should use an external power bus.

Please take this discussion into the main forum where it will have more attention.

DeveloperPermalink Reply by R_Lefebvre on March 4, 2013 at 8:30am

If the rate is too high for the servos, that can cause jitter.  But if the rate is too low, that will not cause jitter. I don't think this is your problem.

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