Proposed Plans for my first Hex build

Raldan

Member
You're right. It was version 2.3. It was a late post :)
I'll look into the escs. But, the mag sensor looks suspicious. It was an HK board from their global warehouse. The one with the MTK gps board included. Thanks, quad makes sense.
I have a KK2.1.5 on its way as well.
 

Motopreserve

Drone Enthusiast
You're right. It was version 2.3. It was a late post :)
I'll look into the escs. But, the mag sensor looks suspicious. It was an HK board from their global warehouse. The one with the MTK gps board included. Thanks, quad makes sense.
I have a KK2.1.5 on its way as well.

Hit the calibrate mag function in the GUI and see if that makes a difference. I am assuming that the mag is on the FC board, and not the GPS, but check to make sure there is no mag on both. That could cause problems.
 

SoCal Blur

Member
If you're talking about Roll indication in the GUI, that's not the MAG it's the ACC. You should try recalibrating the ACC. Make sure that your multi is level first then Calibrate.

Calibrating the MAG should be done after the ACC is calibrated and you have to rotate your multi 360 degrees on all three axis within 1 min. Let me tell you that is tough to do on a 1270mm Octocopter! The MAG is only used for GPS modes and Headsafe mode if I remember correctly.
 

Motopreserve

Drone Enthusiast
If you're talking about Roll indication in the GUI, that's not the MAG it's the ACC. You should try recalibrating the ACC. Make sure that your multi is level first then Calibrate.

Calibrating the MAG should be done after the ACC is calibrated and you have to rotate your multi 360 degrees on all three axis within 1 min. Let me tell you that is tough to do on a 1270mm Octocopter! The MAG is only used for GPS modes and Headsafe mode if I remember correctly.

The Mag mode can be used without the GPS Modes - it's really to hold the yaw (or heading) direction tight (simplified explanation). SoCal is right when describing the proper way to calibrate. But you can hit the calibrate in the GUI just to see if it sparks it to life. Also, keep in mind that the mag is really sensitive to interference, so doing the proper calibration away from power lines, your computer, etc is important to get it all straightened out.

MAG mode means: head lock mode.
That is to say, when there is no yaw input, the multi will point forever to the same direction.
without this mode, you will still have a light deviation (like a tail gyro in heli)

MAG can be activated in all flight stabilization methods
 

SoCal Blur

Member
I knew it was Head "something" mode. :shame: Seems every FC calls it something different. And yes, Head Lock mode is when you use the MAG without GPS so as I mentioned, used in GPS and Head LOCK modes

My point though, is that MAG does not control Roll indications just compass heading. Pitch, Roll and YAW are controlled by the Gyros (Accelerometers) on the Multiwii. So I would think if the Roll stays at zero in the GUI, the ACC needs to be calibrated or the sensor is bad.

Which Multiwii Mega Pro is it? If it is the Blacked version then there is not a MAG on the FC. It's on the GPS unit. And if it is on the GPS unit, you have to be careful that the GPS is pointed in the correct direction (as I found out). There is not a North indicator on the module so it's easy to mount it incorrectly. That will cause you serious problems during GPS Position hold or RTH. You have to be in the GUI to determine the correct mounting direction of the GPS module. You have to face your Multi North, and then rotate the GPS module until it also faces North. Of course if you don't have the Blacked version you can disregard.
 

Raldan

Member
Facing north, I missed that part. I got the MultiWii PRO Flight Controller w/MTK GPS Module from HK. I need to understand what modes I need on to hover with GPS lock. More reading to do. Thanks, guys, I'm learning more everyday.

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Raldan

Member
The Mag mode can be used without the GPS Modes - it's really to hold the yaw (or heading) direction tight (simplified explanation). SoCal is right when describing the proper way to calibrate. But you can hit the calibrate in the GUI just to see if it sparks it to life. Also, keep in mind that the mag is really sensitive to interference, so doing the proper calibration away from power lines, your computer, etc is important to get it all straightened out.

Can ACC and MAG calibration be done with the copter disconnected from the computer's usb? It's a pain with usb cord hanging off the board.
 

Motopreserve

Drone Enthusiast
Can ACC and MAG calibration be done with the copter disconnected from the computer's usb? It's a pain with usb cord hanging off the board.

You can probably get a Bluetooth device for changing parameters (PID) and calibration. It's done via an android app.

Make sure you get the different flight modes on different channels/switches so you can deal with them independently.

For instance: I have a 3-position switch set up to be A) ACRO mode, B) horizon mode, C) horizon with mag mode. On another I have A) nothing, B) Baro mode and C) GPS Hold. Then the RTH is on a 2-position switch on/off. That way you know you can choose anything you need and know what's working etc.
 

Raldan

Member
Thanks, I needed an excuse for a radio with more than 6 channels. Recommendations for a Spektrum compatible unit?
 

Motopreserve

Drone Enthusiast
Thanks, I needed an excuse for a radio with more than 6 channels. Recommendations for a Spektrum compatible unit?

I went with Futaba. Not too familiar with the Spectrum stuff. Tarranis is all the rage these days. Can't touch the features for the money...
 

Raldan

Member
My son and I rebuilt my Quad after another crash. We have now learned to flash my Turnigy Multistar 30A escs with SimonK's latest version of software. Thanks to rctestbench for this YouTube video. http://youtu.be/3py4t_Litak

Build an 6-pin adapter for my USBASP interface with help from Ripcurl777's tutorials videos: http://youtu.be/wzXEmvMw-kA & http://youtu.be/UWw-xdAIdKo

Flashed all 10 esc's in about 15 mins. Hope to get some usable PID settings for a starting point for our next go-around.

Progress...
 

Raldan

Member
Time to tune the gps on HK multiwii pro

The quad hovers well in angle and horizon mode. The hover is smooth. Baro is a no go. Copter will not lift off in baro mode.

GPS mode is another story. I do get gps hold, since I spent one battery (7 mins) hovering in place without touching the a/e stick and using throttle to keep it in the air. The copter orbited in a circle about 20 ft in diameter. The copter continually jitters as it flies. I have done acc gyro and mag calib. I get 6 to 8 Sats. What PID settings do I adjust to lessen this behavior?
 

SoCal Blur

Member
The quad hovers well in angle and horizon mode. The hover is smooth. Baro is a no go. Copter will not lift off in baro mode.

GPS mode is another story. I do get gps hold, since I spent one battery (7 mins) hovering in place without touching the a/e stick and using throttle to keep it in the air. The copter orbited in a circle about 20 ft in diameter. The copter continually jitters as it flies. I have done acc gyro and mag calib. I get 6 to 8 Sats. What PID settings do I adjust to lessen this behavior?

If I remember correctly, you can't lift off in Baro mode because it is trying to hold at its current altitude. You have to be in the air and then switch to Baro mode so it will hold its altitude. Get it into a hover and switch it to a mode with Baro turned on. It should hold its altitude. Be careful not to play with the throttle in that mode. If you turn up the throttle accidentally while in Baro mode and then switch out of it, the actual throttle settings will kick in and it will shoot up like a rocket!

I think the 20ft circle (also known as the toilet bowl effect) is usually due to either not having your Magnetic Declination programmed into the Multiwii or perhaps your motors aren't level.
 

Motopreserve

Drone Enthusiast
Don't take off in Baro - SoCal is right. It will fight you tooth and nail. And make sure you cover the Baro with some foam and allow it to acclimate to the temp outside. It can cause all sorts of mayhem.
 



Raldan

Member
You will get more air time if you reduce the airflow restriction under the motors.....
Will do once I get some flight experience.

Still have jittering and TBE in gps modes. The mag dec is right and the motors are level. Any thoughts on which parameters affect gps lock?
 

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