return home or failsafe the naza

[crash pilot]

I was wondering about the naza if the battery was to drop to low what happens.Does it start to come home or does it go into fail-safe and drop like a brick . I have seen videos of return home and fail-safe if loss of signal, but what about to low battery i say this as when i eventually get one i wont be able to buy fpv for it straight away. So wont be able to see on screen display. Forgive me if this has been answered somewhere but i cant see it anywhere.

[nub]

time your flights, set your timer to the 1/2 way point of no return

[ChrisH]

I wondered the same until the other week. I ignored the flashing red light for a little too long to watch my quad descend elegantly into the middle of a rape seed field in full flower! 15 minutes to find it. Now fitted with an audible alarm! 

So answer is: a safe descent but no RTH when second voltage level is reached! Maybe that should be a future enhancement on the Naza? 

The above assumes that you have the option turned on in the assistant of course, otherwise brick like imitations could ensue! 

[SimonS]

With the Naza Voltage alarm (correctly) set up you will get an orange warning when you are getting low. When you get the red then either you land or it does!
The Naza warning cannot be used with mixed battery voltages or capacities.

An alternative is to switch off the Naza warning and use an OSD to monitor battery consumption either via voltage or mAh used.

[ChrisH]

Simon, I';m confused. I thought that the low voltage gave the same warning, red flashing LED, for stage 1 and 2, just the FC reaction is different? Just had a quick look at the 1.08 quick start guide for 3.12 and orange flashing seems to imply failsafe activated! When the second stage is activated you don';t have a choice, it lands!!

Moral is probably if you see any LED flashing, land! 

[Hands0n]

How own aspirations for the Naza M Lite are for it to switch into RTH mode as soon as the first battery alarm condition arises, giving it sufficient time to get its ';arris back here.  Then it can land      Thats the plan ...

[ChrisH]

Sorry to disappoint but the only RTH you';ll get is one you initiate yourself! 

The Naza warns of low voltage then just lands! No control either when stage two kicks in, just lands without input from you!

Have to keep an eye on the LED! 

[crash pilot]

  WOW THANKS GUYS FOR ALL YOUR REPLIES i wondered how it worked so an alarm must be fitted or timed on my radio dx8. As my user name states crash pilot i am always planting something in the ground and i dont mean plants  . Ok my mind is made up to buy naza 2 with TBS frame motors and esc,s so i needed the info. So i will get me mate to run around underneath it with a blanket all day  . Seriously thank you all very much i love this site its very helpfull thank you Andy.       

[Hands0n]

Sorry to disappoint but the only RTH you';ll get is one you initiate yourself! 

The Naza warns of low voltage then just lands! No control either when stage two kicks in, just lands without input from you!

Have to keep an eye on the LED! 

Bah! That really sucks       Best stay away from water, or fit floatation devices 

[ChrisH]

Come back sooner over water! 

[SimonS]

Simon, I';m confused. I thought that the low voltage gave the same warning, red flashing LED, for stage 1 and 2, just the FC reaction is different? Just had a quick look at the 1.08 quick start guide for 3.12 and orange flashing seems to imply failsafe activated! When the second stage is activated you don';t have a choice, it lands!!

Moral is probably if you see any LED flashing, land! 

Sorry, you are correct that there is only a red LED for the LV warning. I was remembering the settings in the assistant which shows orange for the first stage. There are two stages to the voltage warning. The first stage is just the red continuous flashing.  In the second stage the throttle position for the hover starts to move up from 50% to 90%. The time difference between the two levels depends on how you have set up the system.  If you do nothing it will land rather than the alternative option of falling out of the sky.

RTH, if set up correctly, can be invoked via a switch or a loss of signal. You have the option in the Naza assistant to set it to land at its current position or RTH.

The real moral is to make sure that you know exactly what the different colours and sequences of LED mean

[ChrisH]

I wonder what would happen if during stage 2 of the LV process, you switched the RTH on? Difficult to prove but I expect it wouldn';t change anything!

Once it';s on the way down.... 

[Hands0n]

I';m presuming that by then there';s insufficient power to perform a full RTL (at least without falling out of the sky before it got back).  The earlier advice to time the flight to 50% before making your way back is sound advice. 

[Biffa]

I';m presuming that by then there';s insufficient power to perform a full RTL (at least without falling out of the sky before it got back).  The earlier advice to time the flight to 50% before making your way back is sound advice.

Correct. The same would apply to any FC board though, if there is insufficient power to get home then that';s that. At least with the Naza it lands rather than floats down like a stone

[Hands0n]

... lands rather than floats down like a stone

Ah, thats a happenstance that I have oft occasioned    Not so much of late now that I';ve got one of them thar fangled battery monitors. Screeches like my first wife, it does. Can hear it a mile off.

A thought does occur to me though - that being conflicts between the Naza (or any FC that does this) and the ESC that have low voltage cutoff (LVC) in that they power down the motors at a specific voltage.  Instructions included with the ESC state LVC is 2.6/2.85/3.1 volts per cell (low, medium,high).  So I guess one has to set the LVC to much less than the FC to give it a chance to do its thing. Otherwise the ESC is going to completely undermine the FC and the skyfall becomes inevitable.

Thoughts?

[Biffa]

A thought does occur to me though - that being conflicts between the Naza (or any FC that does this) and the ESC that have low voltage cutoff (LVC) in that they power down the motors at a specific voltage.  Instructions included with the ESC state LVC is 2.6/2.85/3.1 volts per cell (low, medium,high).  So I guess one has to set the LVC to much less than the FC to give it a chance to do its thing. Otherwise the ESC is going to completely undermine the FC and the skyfall becomes inevitable.

I have always programmed my ESCs to the lowest LVC (or off if possible) regardless of what I am flying. But I guess if there is two things looking for an LVC point (ESC or FC), the highest one would react first so ideally you would want the Naza to land rather than the ESCs powering down, leading to that ';falling from the sky'; situation.

That would mean the FC LVC having to be higher than the minimum you can set the ESC to. I haven';t even taken the thing out of the box yet

[Hands0n]

This Naza will be the first FC I';ve had that has its own voltage sensing.  So I do want to get it right. I';ll set the ESC to lowest, or off.

Also, I do intend to arm the APM 2.5 with the AttoPilot power hook-up in due course. http://www.ebay.co.uk/itm/APM2-5-AttoPilot-Voltage-Current-Sense-Breakout-1-58A-with-Battery-Connectors-l-/251295266241?pt=UK_ToysGames_RadioControlled_JN&hash=item3a825d75c1

I think I';ll still use the loud audio alarms also, set higher than needed to give me a fair indication that I should get away from trees, water or other inaccessible areas. I';d hate to see all that kit disappear while the Naza does its thing in good faith    You';d see a grown man cry