DJI Naza-H GPS

[Stumblebee]

Originally Posted by NexxuSix

Please be careful with your GPS units. So far every dealer I have worked with seems to confirm the there is no repair service available... If you suffer a boom strike, most likely you will take out your GPS as well.

As for DJI, they still have not answered my request for repair...

Perhaps you are looking in the wrong places for a repair to your GPS cable. Do you have a technical school in your area that teaches electronics? Most electronics curricula include basic soldering and some even deal with micro-soldering. If there is a tech school nearby, a quick visit and a couple of boxes of doughnuts may solve your problem. (Yup, students work for food)

[Stumblebee]

Originally Posted by zeeflyboy

Just a thought, you think it's possible you shorted something out when the wire got cut? Could easily have had a momentary short circuit that could have caused some damage to the Naza I guess?

I am also thinking along the lines of simple troubleshooting. This was a crash scene so I would start with the basics. In networking, the constant mantra is "always start with the physical layer" for troubleshooting. I would disconnect everything and check all connectors, male and female. I would check for any dirt on the contacts of every component. I would take a very good look at each and every wire and its connectors. A very light spray of contact cleaner cannot hurt at this point. Start with the simple things first. After you have confirmed that everything is clean and undamaged, try re-connecting everything except the puck and see what happens. If nothing else, you may have eliminated some areas of physical damage from the equation.

This is a bit of an aside. I just took a good look at my puck under a magnifying glass. I am having a hard time identifying the fastener DJI is using. It almost looks like the screws are torx with deliberately mangled heads. Can anyone shed some light on this?

I have used DJI technology for quite awhile and my experience is that it is engineered to stand up to the entire New York Jets offensive line. Embedded systems technology is pretty tough these days.

[Stumblebee]

Originally Posted by R_Lefebvre

If DJI were at all concerned with their customers, they should make the GPS cable detachable at the puck.

Hmm... The problem I see with that is that every physical connector introduces a potential point of failure due to the physical nature of electrical contacts. Hard wiring is the way to go whenever possible.

[flim63]

I was waiting for the wind to go away, but in Palmdale that can takes weeks. So with 14 Kts advertised at the airport 4 miles away, I wanted to show it off to visiting family.



I'll make a test flight with the Helicam Solutions mount this weekend and then post it for sale. I just bought a Bergen Observer and need to placate the spouse.

[NexxuSix]

Originally Posted by R_Lefebvre

That's crazy. All this from a boom strike? You wouldn't believe the crashes I've had.

Check this one out:

http://youtu.be/fnC0YIENfYg

Just skip to the half-way point if you want. Basically, this is an Octocopter, and the canopy wasn't secured well enough. The canopy popped off in flight, and damaged 5 propellers, and I think one propeller rotated on the boom making the terrible yaw, otherwise I think it would have survived.

It fell from that height, and smashed upside-down, then bounced. The avionics stack was squished flat. It's all fine. Just had to replace a few wires that got yanked.

Here's another, this one landed upside down on pavement. The GPS was shashed to oblivion, but the IMU is fine.

[IMG]http://api.ning.com/files/XmwcPoxLHk9eR5gKdVbfyfr7gCs5ozxbRFyj0vEMNL9pWtTpy5 pg2ZMivrnenocIS1S-UX-kIRVENI*btMInoQ__/DSC00765.JPG[/IMG]

Nice video... And a pretty bad crash. Sorry for your losses...

I had a closer look at the setup software tonight. I guess I didn't see the message earlier, but I'm getting an "Other Err[25]" in the lower right hand corner of the set up screen. I also noticed that one of the accelerometers is "stuck" at -16. All other gyros and accelerometers respond to movement. Obviously the boom strike did more damage than just tear off the GPS unit.

I sent out another email to DJI sales and support... If I get a response, I'll let you guys know how it goes...

[NexxuSix]

Originally Posted by zeeflyboy

Just a thought, you think it's possible you shorted something out when the wire got cut? Could easily have had a momentary short circuit that could have caused some damage to the Naza I guess?

After seeing the "Other Err[25]" message on the setup screen, I'm beginning to think amongst the same lines... The blade cut and shorted all the wires together, resulting to a total system failure.

[R_Lefebvre]

Originally Posted by Stumblebee

Hmm... The problem I see with that is that every physical connector introduces a potential point of failure due to the physical nature of electrical contacts. Hard wiring is the way to go whenever possible.

Generally yes, however, the GPS puck is not mission critical. Loss of the GPS should not result in a crash necessarily. The risk is worth it, in this case.

At the very least, allow users to open the puck to replace the cable at the solder points. But it sounds like they aren't interested in that, since they used security screws. I really don't understand the point of that.

This is going to happen to people *a lot*.

I had a closer look at the setup software tonight. I guess I didn't see the message earlier, but I'm getting an "Other Err[25]" in the lower right hand corner of the set up screen. I also noticed that one of the accelerometers is "stuck" at -16. All other gyros and accelerometers respond to movement. Obviously the boom strike did more damage than just tear off the GPS unit.

My understanding is that inside the flight controller, the gyro/accels are mounted on a little mass, maybe a block of aluminum? That block is vibration isolated from the case on little foam bits, and it is attached to the I/O section with a small ribbon cable.

My guess is that the shock made that puck move too far inside the case and it damaged the ribbon cable. Just a guess.

Sucks that an already expensive helicopter crash just got $400+ more expensive.

[Wesley888]

This is the first time I've ever seen the GPS unit (from any version of DJI product) getting damage from a crash though.

[zeeflyboy]

I've yet to have a boom strike in any if my flying/crashing too, so while it most certainly can happen I think it was just quite unlucky here.

Generally speaking boom strikes are not all that common unless running too low head speed, blades too loose in the grips or some seriously hard flying with dampers that are too soft.

[Wesley888]

Very true. I have crashed my heli no less than 30 times while testing things. Not once have boom strike.

[Stumblebee]

Originally Posted by flim63

I was waiting for the wind to go away, but in Palmdale that can takes weeks. So with 14 Kts advertised at the airport 4 miles away, I wanted to show it off to visiting family.

I'll give you points for bravery. My handbook on superstitions warns against displaying heli piloting skills to visiting relatives, especially the spouse's relatives. Such things could anger the heli-gods.

[NexxuSix]

Originally Posted by zeeflyboy

I've yet to have a boom strike in any if my flying/crashing too, so while it most certainly can happen I think it was just quite unlucky here.

Generally speaking boom strikes are not all that common unless running too low head speed, blades too loose in the grips or some seriously hard flying with dampers that are too soft.

In my case, I broke a servo, which left plenty of room for the blade to hit the boom. In theory, a boom strike shouldn't happen, but it does because the blade pivots back during impact putting at a very nice angle to do good damage with. So many times I thought about building a deflector wedge to deflect blades during a crash... But it wouldn't look all too great on the heli boom Just a thought though...

[NexxuSix]

Originally Posted by NexxuSix

Apology accepted

Thank you for the information. I don't know how hardy the electronics are, but hopefully the unit will power up and calibrate. If it doesn't, then I will most likely buy another GPS unit.

Just a little update folks...

Please be careful with your GPS units. So far every dealer I have worked with seems to confirm the there is no repair service available... If you suffer a boom strike, most likely you will take out your GPS as well.

As for DJI, they still have not answered my request for repair...

An update to my update:

I have received an email from DJI asking me to give them my dealers name. They are going to start working at the dealer level... Until then I will have to wait and see what happens from here. I will keep you all updated.

I have seen a GPS protector amongst the Naza-M crowd... Any thoughts on this?
http://www.rcgroups.com/forums/showthread.php?t=1746472

[nightflyr]

Originally Posted by NexxuSix

An update to my update:

I have received an email from DJI asking me to give them my dealers name. They are going to start working at the dealer level... Until then I will have to wait and see what happens from here. I will keep you all updated.

I have seen a GPS protector amongst the Naza-M crowd... Any thoughts on this?
http://www.rcgroups.com/forums/showthread.php?t=1746472

Not quite sure how you could secure it to your boom...
But it is a nice idea for multi-rotors.

[viper3two]

Originally Posted by NexxuSix

An update to my update:

I have received an email from DJI asking me to give them my dealers name. They are going to start working at the dealer level... Until then I will have to wait and see what happens from here. I will keep you all updated.

NexxuSix that's kinda crappy for the money spent on that thing, just a boom strike and it failed the IMU also? And they won't at least replace the IMU? I was thinking of getting one also but not after this story. I once had an mcpx that the main board failed on from about 50ft up, it hits the pavement hard and parts go everywhere. I send it in a box to Blade and they replaced the entire heli...no charge. DJI should at least replace the IMU for the 2 hours you got to fly the thing.

[Valkman]

Has anyone put a connector block on the GPS cable or soldered in an extension? I can't see an issue so long as they are good joints they won't affect resistance.

[txemakastello]

Unboxing the DJI Naza H. Tests, videos and impressions coming soon...


[ame]http://www.youtube.com/watch?v=g_J9r0Vpzww[/ame]

[Stumblebee]

Originally Posted by Valkman

Has anyone put a connector block on the GPS cable or soldered in an extension? I can't see an issue so long as they are good joints they won't affect resistance.

I know there has been a message or two regarding folks who have shortened the cable a bit. I would want to really inspect that cable before doing anything to it. My stock connector goes across four pins. I assume that means four wires by the look of the connector. What I do not know is if there are twisted pairs? Wires are twisted in pairs to counter-act an electrical effect known as cross-talk which is a signal in one wire interfering with a signal in another wire. This twisting is done if the signal on the wires has a frequency component. I do not know if the GPS signals have a frequency component when they travel between the puck and the Naza unit. If those wires are in twisted pairs, undoing the twists to install a connector block or extension may cause signaling or cross-talk problems. If the wires in the cable are untwisted, there may be no concern.

[Stumblebee]

Guys, is it possible that we haven't even begun to explore what is REALLY possible with the NazaH/GPS? This is no mere pipe dream. Check out the Raspberry Pi computer. Check out its price ( real cheap), its size, its power requirements and its ARM processor. This is a full powered computer that is adaptable to our multi-rotor platforms. Just think of the possibilities for what we do. My usual UN-reliable sources tell me that Naza is also heavily involved in ARM processors and Linux. As I see it, this is just the beginning. These two technologies can take us a very long way past anything Wooking Waypoint can do and do it a LOT cheaper. We now have the technology, the price and the brain power.

[NexxuSix]

Originally Posted by Stumblebee

Guys, is it possible that we haven't even begun to explore what is REALLY possible with the NazaH/GPS? This is no mere pipe dream. Check out the Raspberry Pi computer. Check out its price ( real cheap), its size, its power requirements and its ARM processor. This is a full powered computer that is adaptable to our multi-rotor platforms. Just think of the possibilities for what we do. My usual UN-reliable sources tell me that Naza is also heavily involved in ARM processors and Linux. As I see it, this is just the beginning. These two technologies can take us a very long way past anything Wooking Waypoint can do and do it a LOT cheaper. We now have the technology, the price and the brain power.

I have read that there are hacks out there for the Naza GPS to get it interfaced to a pc and GUI. Yes, the RaspberryPi is a very interesting sbc, and quite capable of many things. The only drawback might be the lack of programmers or Linux fans in the heli forums. I'm sure, given enough time someone can interface the Naza GPS to the RaspberryPi and have a multiple waypoint platform developed. It would be an interesting project, no doubt.