That's opposite of what you wrote before.N017RW said:
This says If it's warmer you read higher which means you'll actually be lower than the altimeter says.
Before you said if the temp lowers you'll actually be lower than the altimeter says.
Incorrect altitude
- Thread starter edonovanl
- Start date
This says If it's warmer you read higher which means you'll actually be lower than the altimeter says.
Before you said if the temp lowers you'll actually be lower than the altimeter says.
N017RW
Premium Pilot
cahutch said:
C'mon man, back up.
It's not opposite anything I said...
Warmer to colder- read lower than actual,
Colder to warmer- read higher than actual.
Sorry, I guess I'm just confused.
Does that mean the reading is lower than actual or you should read it lower than what it shows?
This confused me and seems backwards.
Does that mean the reading is lower than actual or you should read it lower than what it shows?
This confused me and seems backwards.
That means if you go from warmer to colder the altimeter reads higher than it should.N017RW said:
I received a new Vision+ V3.0 on Monday but it looks like I have a faulty barometer.BlackTracer said:
When turning it on at home the DJI Vision app altitude immediately starts counting down and eventually stabilizes around -2000 feet after several minutes.
I flew for the first time yesterday not realizing what problems this could cause. The outside temperature was about 48 degF and I took off when the altitude showed about -433 feet. I started testing Return to Home when the altitude showed about -375 feet and it looks like it started first to climb to altitude zero feet and then higher to the RTH height. I stopped the Return to Home pretty quickly since this was my first flight and was able to land normally.
Following is a screen capture shortly after starting Return to Home.
Anything I should do before returning it? FYI the Vision+ I received on Monday has a serial number PH645497XXX from Amazon.
- Scott
Attachments
I calibrated transmitter using RC System Assistant and then channels in Phantom 2 Vision Assistant. Then just before first flight I did compass calibration.Kev the Frog said:
After first flight I did Advanced Calibration but that didn't change bad altitude symptoms - it appears this only calibrates the gyroscope and accelerometer, not the barometer.
- Scott
Scott848 said:
This RTH behavior makes sense to me. The part of the firmware that handles the RTH altitude is assuming the home point is at 0 altitude. So in your case and assuming an RTH height of 66 ft, it would have flown up 375 ft to 0 then 66 more feet and returned at that height. So a malfunctioning barometer is really going to eff you up.
I've flown more than 50 flights and my altimeter has never been correct. It even changes when I swap out batteries so I just use whatever it says as a reference. RTH won't be a problem because the Phantom doesn't care what altitude it's at and doesn't calculate how far to earth. It descends very slowly and when it reaches the ground and realizes it's stopped, the motors shut off.
I'm going to try a Ground Station run today for the first time and I'm curious what happens when I set the waypoint altitude at 100 feet, will it actually go to 100 feet? If so, then I'll know that it's just calculating using whatever it records as Home altitude as a reference...
I'm going to try a Ground Station run today for the first time and I'm curious what happens when I set the waypoint altitude at 100 feet, will it actually go to 100 feet? If so, then I'll know that it's just calculating using whatever it records as Home altitude as a reference...
cahutch said:
Do an adv IMU calibration. The NAZA has an IMU which has the altimeter/barometer sensor that estimates the altitude based on pressure. Now many here argue the MC Temp Warning is bug and should be ignored. That MC temp warning it there to warn us about inaccuracies when calibrating. Without the props spinning the Phantom's internals heat up and create pressure and throws the sensors off. This is why you should not ignore the MC temp warnings. Depending on your climate, the warning can appear quicker than others. Mine appears about a minute after idling. Mind you, im in Australia. The longer it heats up, the longer it will take to complete the Adv IMU (it can even fail if too hot).
To prevent the MC Temp warning, and to do an accurate quick adv IMU calibration:
Find a surface that is levelled with the horizon in all axis. In other words, if you place a marble on that surface, it wont roll. This is important to prevent the yaw drifts.
Make sure the phantom is cold and has not been turned on in the last hour or so.
Have the phantom assist started and on the screen ready for calibration.
Plug the usb in and turn on phantom and immediately do the advance calibration.
Keep the phantom dead still. Wait for the green ticks. It should take 2 minutes.
Done.
N017RW
Premium Pilot
The MC temp warning is meaningless to me.
I live in S. Fla where my house temp is never above 75 degrees F.
If I move to complete the PC to P2 connection steps as fast as I can it takes maybe 30 seconds TOPS and I still get the temp warning? Without even arming the motors?
No way.
Hooey I say.
What is generating all this heat that folks speak of?
You think the props provide adequate cooling to the internals?
How?
The arm vents are not configured to maximize the vertical airflow produced by the props to pressure differential flow horizontal across the ESCs, let alone the Naza.
More Hooey.
Look elsewhere.
I live in S. Fla where my house temp is never above 75 degrees F.
If I move to complete the PC to P2 connection steps as fast as I can it takes maybe 30 seconds TOPS and I still get the temp warning? Without even arming the motors?
No way.
Hooey I say.
What is generating all this heat that folks speak of?
You think the props provide adequate cooling to the internals?
How?
The arm vents are not configured to maximize the vertical airflow produced by the props to pressure differential flow horizontal across the ESCs, let alone the Naza.
More Hooey.
Look elsewhere.
Place your hand on top of the phantom and let her idle.
You have a GPS module and Wifi Module that is generating heat. The Wifi module runs bloody hot!!
And no, I don't the props are adequately cooling the phantom through those small vents. I'm sure its much cooler in the higher altitudes.
You have a GPS module and Wifi Module that is generating heat. The Wifi module runs bloody hot!!
And no, I don't the props are adequately cooling the phantom through those small vents. I'm sure its much cooler in the higher altitudes.
N017RW
Premium Pilot
No way iall this thermal generation and transfer happens within the 30 sec. I achieve.
No way.
It's hooey.
No way.
It's hooey.
I also live in Florida so not sure what the summer will bring since I'm just getting started. I also get an MC temp warning way too soon for anything to get too warm before the IMU advanced calibration completes.
My altimeter typically reads between -250 and -70 so when I try Ground Station, or RTH, that negative gets added to the height settings. Yesterday I set GS altitude to 0ft and sure enough it flew up and up anyway because my starting altitude was -173ft. Think I'm going to send it back in for warranty since that could make my RTH height very high, increasing the chance that in that situation the drone might run out of battery and plummet.
My altimeter typically reads between -250 and -70 so when I try Ground Station, or RTH, that negative gets added to the height settings. Yesterday I set GS altitude to 0ft and sure enough it flew up and up anyway because my starting altitude was -173ft. Think I'm going to send it back in for warranty since that could make my RTH height very high, increasing the chance that in that situation the drone might run out of battery and plummet.
I received the replacement Phantom from Amazon today and the barometer is working great.Scott848 said:
This one shows an altitude in the DJI Vision app of about +4 feet about a minute after I power on the Phantom. The defective Phantom showed -300 feet as soon as I could get into the app and kept on counting down until it stabilized around -1700 feet.
FYI the serial number on this one is PH645488XXX.
- Scott
Scott848, how did your replacement with Amazon work? Did you request a refund? Seems I can only get a refund and re-order?
I am two days from reaching my 30 days since purchase and my altitude is always -80 to -250 feet, which sucks.
I am two days from reaching my 30 days since purchase and my altitude is always -80 to -250 feet, which sucks.
There is a Return or Replace Items option on the website. When doing that I took the option to replace it and they shipped out the new item before I returned the defective Phantom.edonovanl said:
I filled out the form Thursday night and received the new Phantom on Saturday. There is a hold on my credit card for the amount of the 2nd Phantom until they receive the 1st Phantom.
- Scott
When I clicked on the return or replace button, my only option was refund so I sent it back today. I have a P2V+v2 without a gimbal/camera so I'm just going to practice with it for a while, then see what happens in the market: new Phantom or Inspire version...
My P2V+V2 behaves exactly like it should, goes to my preset RTH height and descends. Because of the negative altitude on the v3, it zoomed up to 263 feet plus the 66 feet that I set for RTH height - not good, and did the same thing with ground station.
My P2V+V2 behaves exactly like it should, goes to my preset RTH height and descends. Because of the negative altitude on the v3, it zoomed up to 263 feet plus the 66 feet that I set for RTH height - not good, and did the same thing with ground station.
So say your RTH height is set to 100 meters (like mine)
You power up, connect the app and the altitude drops to -100 meters. You take off and fly around relatively low at ~10 meters, then initiate RTH.
The RHT height is 100 meters but the Phantom reads it's current height as -90 meters.
It will ascend to +100 or ~200 meters high, RTH and descend until it touches the ground at ~-100 meters.
It climbs higher than you planned but better higher than lower unless your battery is very low.
The danger here is that it could climb too high into dangerous airspace (unlikely) or it may not have the battery power remaining to climb that high and then descend again that slowly. So it could fall out of the sky before it can auto land.
Scenario 2, your RTH height is again set to 100 meters
You power up, connect the app and the altitude climbs to +100 meters. You take off and fly around relatively low at ~10 meters, then initiate RTH.
The RTH height is 100 meters but the Phantom thinks it's already at 110 meters.
It will RTH at the current altitude of 10 meters and descend until it touches the ground at ~+100 meters.
The danger here is of course that it's returning too low and could crash into a tree or building.
There are two ways around the problem.
Cycle power on the Phantom so it resets the altitude to zero after it's warmed up. But watch it after you takeoff. It could change again after it cools down.
Or, better yet, after takeoff, while performing a hover test at around two or three meters high and 10 meters away from the previous home point, reset the home point by flipping S2 and your altitude should reset to Zero in the air.
Does the app give you a way to reset home now or is the S2 switch still the only way? Does the S2 switch still work to reset home?
You power up, connect the app and the altitude drops to -100 meters. You take off and fly around relatively low at ~10 meters, then initiate RTH.
The RHT height is 100 meters but the Phantom reads it's current height as -90 meters.
It will ascend to +100 or ~200 meters high, RTH and descend until it touches the ground at ~-100 meters.
It climbs higher than you planned but better higher than lower unless your battery is very low.
The danger here is that it could climb too high into dangerous airspace (unlikely) or it may not have the battery power remaining to climb that high and then descend again that slowly. So it could fall out of the sky before it can auto land.
Scenario 2, your RTH height is again set to 100 meters
You power up, connect the app and the altitude climbs to +100 meters. You take off and fly around relatively low at ~10 meters, then initiate RTH.
The RTH height is 100 meters but the Phantom thinks it's already at 110 meters.
It will RTH at the current altitude of 10 meters and descend until it touches the ground at ~+100 meters.
The danger here is of course that it's returning too low and could crash into a tree or building.
There are two ways around the problem.
Cycle power on the Phantom so it resets the altitude to zero after it's warmed up. But watch it after you takeoff. It could change again after it cools down.
Or, better yet, after takeoff, while performing a hover test at around two or three meters high and 10 meters away from the previous home point, reset the home point by flipping S2 and your altitude should reset to Zero in the air.
Does the app give you a way to reset home now or is the S2 switch still the only way? Does the S2 switch still work to reset home?
One thing I'm not clear on. According to DJI, here ...
http://wiki.dji.com/en/index.php/Phanto ... Home_Point
"The current position of the quad-rotor will be saved as home point when you push the throttle for the first time"
This is for the original Phantom. Is this true for the Phantom 2?
I always thought the home position was set as soon as the GPS got a lock.
Directions for resetting home point are here...
http://wiki.dji.com/en/index.php/Phanto ... Home_Point
https://www.youtube.com/watch?v=B9GAvKuarr0
http://wiki.dji.com/en/index.php/Phanto ... Home_Point
"The current position of the quad-rotor will be saved as home point when you push the throttle for the first time"
This is for the original Phantom. Is this true for the Phantom 2?
I always thought the home position was set as soon as the GPS got a lock.
Directions for resetting home point are here...
http://wiki.dji.com/en/index.php/Phanto ... Home_Point
https://www.youtube.com/watch?v=B9GAvKuarr0
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