Hi,

First post here. I read a little about GPS controlled modes, and the issues people have had here when the drone switches to ATTI mode or OPTI mode and weird things start to happen. I bought the Mavic 2 Pro because of it's camera. I intend to fly in dark places like abanonded mines where the GPS signal will mostly lost, but sometimes might sneak in as I fly close to openings like in my photo below. Some mines have much larger open shafts and I will be flying at different altitudes in these mines. Now, I'm assumung the drone will be in ATTI mode when I am well below the surfice? Is ATTI 100% full manuall? If so, I won't be allowed to familiarize myself with ATTI mode until I bring it down there?? I mean, it's not the best place to get to know ATTI mode, the edge I'm standing on in the photo is not very large, to reach it requires a 150 meter abseil, then it's about a 100 meter drop to over the egde to the water, and the water depth is at least 100 meters (I know the depth of that mine). Not the best place to learn ATTI mode, it's not like it's easy to recover it...

I bought the Mavic 2 Pro mostly for it's camera. Little did I know that DJI do not want their customers to fly full manual. I guess I bought the wrong drone, I was fooled by the Pro part in the name. Yes, I should have done more research but now I have it. I can try return it or sell it on, but first I'll try find out if there is a way.

So, is there a hack or trick to force full manual mode? I want to practice flying in full manual before taking it underground, and I certainly don't want it switching been GPS, ATTI and OPTI modes as the drone pleases, I want full control of it.



I read about the usage of Mavic 2 Pro in K2, The impossible descent. The pilot had modified his drone to override top speed and height restrictions:
https://dronexl.co/2020/07/22/dji-mavic-2-k2-mountain-delivers-medicine-rescues-climber/
How did he do that? Can his methods be used to force full manual mode with the Mavic 2 Pro?

You can enable ATTI on the Mavic by changing a custom setting in DJI Assistant and replacing Tripod or Sports mode.
https://www.thedroneu.com/blog/atti-mode-mavic-2-pro-hack-zoom/

Note you NEED the older, specific version of assistant linked there NOT the latest one off the website.

It works fine - ATTI is definitely worth practicing with before using it near rocks or in confined areas.  Its not hard but it is different.  Invest in some prop guards.

gnirtS Posted at 12-11 17:07
You can enable ATTI on the Mavic by changing a custom setting in DJI Assistant and replacing Tripod or Sports mode.
https://www.thedroneu.com/blog/atti-mode-mavic-2-pro-hack-zoom/

Ahh, thanks for the tip! Does it matter which firmware the Mavic has? As DJI seem insistent on not allowing manual ATTI, have they prevented that DJI Assistant trick with later Mavic 2 Pro firmware?

Also, how did the K2 pilot modify top speed as described in the link I posted? I'm guessing this was by other method than DJI Assistent? Edit: I think I have the answer to this second question now, thanks.

Is ATTI 100% full manuall?

Atti Mode is not "full manual".
In fully manual mode, drones are nearly impossible to fly.
Atti mode still has altitude holding and the drone will behave itself with hands off the sticks.

Now, I'm assumung the drone will be in ATTI mode when I am well below the surfice?
GPS signals don't pass through rock.
Unless the drone has a clear view of a large part of the sky, it won't have GPS.
If you have VPS enabled and lighting and ground conditions are suitable, you would still have VPS for Opti Mode.
If conditions aren't suitable for VPS or it's disabled, what's left is Atti Mode.

In Atti Mode the drone is controllable but has no horizontal position holding ability so it won't stop when you go hands off.
It's still controllable but without "brakes" so you need to use gentle joystick input and flying close to walls or other obstacles is very risky.
If you are flying near obstacles, prop guards are highly recommended.

Something to be aware of ....Altitude is limited in atti mode (p57 of the manual).
Height is restricted to 16 ft (5 m) when the GPS signal is weak and Downward Vision System is activated.
Height is restricted to 98 ft (30 m) when the GPS signal is weak and Downward Vision System is inactivated.

I bought the Mavic 2 Pro mostly for it's camera. Little did I know that DJI do not want their customers to fly full manual.
DJI Phantom drones have switchable Atti Mode.

So, is there a hack or trick to force full manual mode? I want to practice flying in full manual before taking it underground.
You can force the Mavic into Atti mode by covering the GPS receiver with aluminium foil.
Trying to learn to fly in Atti Mode in a mineshaft sounds like a good way to lose the drone quite quickly.
You would definitely need experience before trying in that environment.

If you are serious about underground exploration, there are drones specifically made for use in GPS-denied environments.
Here's one:
https://www.flyability.com/elios-2
https://www.commercialuavnews.co ... -inspections-drones

Hi, MikeCswe. We appreciate your inquiry but unfortunately, the DJI Mavic 2 doesn't support the option for manual ATTI Mode switch.  

Labroides Posted at 12-11 19:05
Is ATTI 100% full manuall?

Atti Mode is not "full manual".

Thanks for the comprehensive answer. A few follow up questions if I may.

So if the GPS signal is weak, then there is an altitude restriction, even if the drone is in ATTI mode? Is it obtaining altitude information by GPS alone? Will the drone in some way try to restrict altitude gain if GPS signal is lost entirely?

The Mavic 2 Pro operator in the movie "K2 impossible descent" disabled height restrictions according to the link: https://dronexl.co/2020/07/22/dji-mavic-2-k2-mountain-delivers-medicine-rescues-climber/
"Bartek eliminated the maximum height restriction that is set by DJI on the Mavic Pro."
How did he do that? By searching I assumed it was with DJI Assistant, but now I am not so sure. Is it possible to eliminate all height restrictions in weak GPS conditions by using Bartek's method? Edit: I found more specific information about this, there are plenty of youtube videos around. I'll get to it and see what I can do.

I'm not that serious into underground exploration and filming that I would consider the Elios 2. If I can't get the Mavic 2 Pro to work I'll get a much cheaper drone with no restrictions and attach a GoPro to it. It's odd that I would have to get a cheap drone in order to do something a more expensive Mavic 2 Pro can't do out of the box. I should have done my research before buying but I never thought the Mavic 2 Pro would be limited this way.

MikeCswe Posted at 12-12 01:51
Thanks for the comprehensive answer. A few follow up questions if I may.

So if the GPS signal is weak, then there is an altitude restriction, even if the drone is in ATTI mode? Is it obtaining altitude information by GPS alone? Will the drone in some way try to restrict altitude gain if GPS signal is lost entirely?

So if the GPS signal is weak, then there is an altitude restriction, even if the drone is in ATTI mode?
When DJI say GPS is weak they mean GPS =zero sats or not enough sats to get accurate GPS position data (that requires a minimum of 6 .. but it may take more too).
When the GPS receiver does not have good GPS position data, the drone will be in either Atti Mode or Opti mode.

Is it obtaining altitude information by GPS alone?
The drone's altitude data comes from a barometric sensor, not GPS.
Will the drone in  some way try to restrict altitude gain if GPS signal is lost entirely?
See my first point above.

How did he do that? By searching I assumed it was with DJI Assistant, but now I am not so sure. Is it possible to eliminate all height restrictions in weak GPS conditions by using Bartek's method?
He must have hacked the drone's programming.

It's odd that I would have to get a cheap drone in order to do something a more expensive Mavic 2 Pro can't do out of the box.
I'm not sure what the imagined problem with the Mavic 2 is.
If you are down in a mineshaft, there will be no sats available, so it will be in atti mode unless there is good lighting and the floor has a recognisable texture.
And you can turn off the VPS which would mean OPTI Mode isn't an option.

How high above the launch point do you anticipate flying?

MikeCswe Posted at 12-11 17:14
Ahh, thanks for the tip! Does it matter which firmware the Mavic has? As DJI seem insistent on not allowing manual ATTI, have they prevented that DJI Assistant trick with later Mavic 2 Pro firmware?

Also, how did the K2 pilot modify top speed as described in the link I posted? I'm guessing this was by other method than DJI Assistent? Edit: I think I have the answer to this second question now, thanks.

Works on any M2 firmware provided you use the older version of assistant.  You need to repeat the modification after a firmware upgrade though.

The only thing you need is that specific older version of assistant.

MikeCswe Posted at 12-12 01:51
Thanks for the comprehensive answer. A few follow up questions if I may.

So if the GPS signal is weak, then there is an altitude restriction, even if the drone is in ATTI mode? Is it obtaining altitude information by GPS alone? Will the drone in some way try to restrict altitude gain if GPS signal is lost entirely?

DJIs official product tree is roughly
Mavic - consumer
Phantom - semi professional
inspire - professional

Mavics do have some features disabled for that reason.

The main issue i can see you having in a mine, any mine is lack of light for the cameras.  No small sensor camera be that gopros or mavic 2s work well in very dark environments.

The max speeds and so on are firmware hacks so different to enabling ATTI mode.  If you have a special use requirement DJI can do it for you - they unlocked a mavic 2 altitude to allow a flight up to 6,000ft from takeoff (actual altitude 28300ft) around Mount Everest for Nat Geo for example.

Thanks again all.

It's useful to know that the height sensing is from a barometric sensor.

Height from take off point could be a few 100 meters above or below. If I start from that ledge in the photo, I might want to fly down from the ledge or up towards the shaft entrance. I'd also like to use it for checking possible tunnels like the ones that can be seen at 1:10 in my video here: https://www.youtube.com/watch?v=abAJLb_Vvnc
I might start from ground level above or on the ice below.

In terms of light, I happen to be a flashlight nerd. I have designed 17mm 40W boost drivers using MP3429 boost IC, capable of driving XHP 70.2 LEDs at over 5 amps from a single 18350 cell. Short run time for sure but I only need short bursts to poke around. I have temperature sensing on the driver so I can prevent overheating, but I'm researching ways to remotely turn the flashlight on and off, possibly by taking Mavic 2 Pro's bottom LEDs as turn on signal. I read somewhere that it could be possible to control those LEDs by remote but that's another story... Anyhow, filming for nice shots (not exploring) would be done where there is enough light, like in the youtube video link above.

I have found the older version of DJI Assistant and installed it. I can now access the parameters. I've done some searching on the parameters and something caught my eye but I have found very limited information about it. On a web page about parameters I found this: "g_config_control_control_mode" 0 = Manual Mode (GPS position and Altitude Stabilization are disabled)
This might be what I am looking for. Has anyone tried flying the Mavic 2 Pro in this mode? I guess I can assign this mode to one of the switch positions and try myself. I know I might break or loose it, but that's on me. I won't be flying anywhere where I can hurt someone or something, and I'm not interested in high altitude or otherwise illegal flying.

Interesting about the special use requirement. If they can make custom changes like that, that would be my preferred method for sure. I'm not sure they'd do it for anybody but it certainly doesn't cost anything to ask.

MikeCswe Posted at 12-12 04:30
Thanks again all.

It's useful to know that the height sensing is from a barometric sensor.

control_mode" 0 = Manual Mode (GPS position and Altitude Stabilization are disabled)
This might be what I am looking for.
I can't imagine why you would want to do without Altitude Stabilisation.
It's very, very useful anad flying would be a lot more difficult without it.

Labroides Posted at 12-12 04:58
control_mode" 0 = Manual Mode (GPS position and Altitude Stabilization are disabled)
This might be what I am looking for.
I can't imagine why you would want to do without Altitude Stabilisation.

Because of this:
Height is restricted to 16 ft (5 m) when the GPS signal is weak and Downward Vision System is activated.
Height is restricted to 98 ft (30 m) when the GPS signal is weak and Downward Vision System is inactivated.

I might have missunderstood your posts, if so I apologize. My understanding from them is that the drone goes into ATTI mode when the GPS is lost, and in ATTI mode height will be restricted to 5m or 30m depending on downard vsision system status, height being measured by the barometric sensor. As I wrote in my previous post, I'd like to get at least 100m height without any GPS signal.

But perhaps these 30m and 5m limits will be there, regardless if altitude stabilisation is disabled? Then I guess I can't get around it myself.

MikeCswe Posted at 12-12 05:00
Because of this:
Height is restricted to 16 ft (5 m) when the GPS signal is weak and Downward Vision System is activated.
Height is restricted to 98 ft (30 m) when the GPS signal is weak and Downward Vision System is inactivated.

Altitude stabilisation means the drone will do the work of maintaining altitude for you.
When you climb and take your hands off the sticks, the drone will stop and hold its altitude.
Without it, you'll constantly be tweaking the sticks up and down to try to maintain altitude.
It will be like atti mode in the vertical axis and added to atti mode giving no stabilisation in th ehorizontal axis, it sounds like a recipe for a disaster in less than 30 seconds.

I guess you're right about that. Oh well, I'll put in ATTI mode, go out and see if stops gaining altitude at 30m. If not, all is fine and I'll do a lot of flying before taking it underground. If it does I'll see if I can find away around it or get a different drone.

MikeCswe Posted at 12-12 11:21
I guess you're right about that. Oh well, I'll put in ATTI mode, go out and see if stops gaining altitude at 30m. If not, all is fine and I'll do a lot of flying before taking it underground. If it does I'll see if I can find away around it or get a different drone.

One more issue you may encounter in a mine or cave is the draft. Reading some spelunkers stories, air drafts can be very turbulent in some specific shafts configuration. Without GPS leash or VPS system efficiently working, I will predict about 30 sec drone life expectations in such situation. Atti mode flight is  impossible to manage in tight spaces and with the slightest breeze. I have experienced this exactly above deep canyon creek, luckily rendering happy recovery ...

None of the mines I have been down into have had strong drafts, and I've been down into a few. Yes, it can happen but I'm not too concerned about it. I don't intend to fly it into the tunnels, more like fly up to it and take peak to see if it's worth exploring.

I've just found a thread on some other forum about flying in a mine underground. In this case a Mavic Mini:
https://mavicpilots.com/threads/bypass-8m-height-limit-with-no-gps.90847/page-2#post-1027455
"But if you sink below the initial altitude, the Mavic Mini will attempt a landing. We then let the Mini sink another 30 feet and put it back on full throttle. The Mini then stops descending at this altitude and you can continue the inspection. Unfortunately, once you are on the ground (about -60 feet) you cannot fly back up."

Now to me that's stupid. You fly below take off altitude and it attempts to land?? Obviously it's not above where it took off, so it sends it's self down into some unknown place and can't fly back up again? If there is water down there it's doomed. Why did DJI implement this? Glad I found this, I certainly have to test this myself under controlled circumstances but it's looking more and more like I need to get some other drone that will allow me to fly by myself, or search through all those youtube videos and webpages about custom firmware hacks. I've flown RC helicopters with no GPS, gyros or other sensors , it takes a bit of practice but at least they don't have hidden self destruct modes.

MikeCswe Posted at 12-13 03:02
None of the mines I have been down into have had strong drafts, and I've been down into a few. Yes, it can happen but I'm not too concerned about it. I don't intend to fly it into the tunnels, more like fly up to it and take peak to see if it's worth exploring.

I've just found a thread on some other forum about flying in a mine underground. In this case a Mavic Mini:

What kind of RC helicopters have you flown? I'm assuming you're referring to a proper collective pitch RC heli???

MikeCswe Posted at 12-13 03:02
None of the mines I have been down into have had strong drafts, and I've been down into a few. Yes, it can happen but I'm not too concerned about it. I don't intend to fly it into the tunnels, more like fly up to it and take peak to see if it's worth exploring.

I've just found a thread on some other forum about flying in a mine underground. In this case a Mavic Mini:

"I've just found a thread on some other forum about flying in a mine underground. In this case a Mavic Mini:
https://mavicpilots.com/threads/ ... page-2#post-1027455
"But if you sink below the initial altitude, the Mavic Mini will attempt a landing. We then let the Mini sink another 30 feet and put it back on full throttle. The Mini then stops descending at this altitude and you can continue the inspection. Unfortunately, once you are on the ground (about -60 feet) you cannot fly back up."

I would not take that as gospel, I would test it out myself because it does not sound right to me. I have never flown in a cave, but I have never heard of a DJI aircraft behaving like that.

Monkey007 Posted at 12-15 13:16
What kind of RC helicopters have you flown? I'm assuming you're referring to a proper collective pitch RC heli???

Why would you assume that? Coaxial and fixed pitch.

Geebax Posted at 12-15 14:10
"I've just found a thread on some other forum about flying in a mine underground. In this case a Mavic Mini:
https://mavicpilots.com/threads/bypass-8m-height-limit-with-no-gps.90847/page-2#post-1027455
"But if you sink below the initial altitude, the Mavic Mini will attempt a landing. We then let the Mini sink another 30 feet and put it back on full throttle. The Mini then stops descending at this altitude and you can continue the inspection. Unfortunately, once you are on the ground (about -60 feet) you cannot fly back up."

You're absolutely right, I should hold my judgement and comments like that until I have tested it myself. I'll post my findings once I get a chance, hopefully this weekend.

MikeCswe Posted at 12-15 14:26
Why would you assume that? Coaxial and fixed pitch.

No offense here; if your experience with RC helicopter is with coaxial and fixed pitch, then you 'might' not have the skills to control a drone in your 'full manual' mode; inside a dark cave, with no GPS and no vision positioning.

Monkey007 Posted at 12-15 16:06
No offense here; if your experience with RC helicopter is with coaxial and fixed pitch, then you might not have the skills to control a drone in 'full manual' mode, in the absence of GPS and vision positioning.

No, you're right. I was certainly not implying that I could. It's just that if it had gone into landing mode after descending below take off altitude (as described in that post) and it had happened to be directly above water, then I'd have preferred to be in a full manual mode. But, as Geebax pointed out, I shouldn't have written those comments before having tested myself.