LibrePilot Forum

General Category => General Discussion => Topic started by: zukenj on April 18, 2017, 03:11:57 pm

Title: Set Failsafe with low battery
Post by: zukenj on April 18, 2017, 03:11:57 pm

Sorry, I looked all over, and did not found information.

Is there a way to set up land when a low battery alarm triggers?

Thanks

Title: Re: Set Failsafe with low battery
Post by: Mateusz on April 18, 2017, 04:27:50 pm

There is code Alessio merged into next doing that, but afaik it's not yet in release so it might be not document yet for that reason. Usually someone writes wiki as soon as feature is in released stable version. It would probably be confusing otherwise.

Title: Re: Set Failsafe with low battery
Post by: TheOtherCliff on April 19, 2017, 03:30:11 am

As far as I know, Landing is a GPS mode.  I would expect the auto landing on low battery to require a GPS.  Your signature did not show a GPS.

Title: Re: Set Failsafe with low battery
Post by: zukenj on April 19, 2017, 02:23:16 pm

TheOtherCliff: Sorry about that, adding my Tomtom car GPS to my signature.

Just kidding. :)

I have a M8N Naza Clone GPS:
http://www.banggood.com/Ublox-M8N-GPS-Compatible-with-DJI-NAZA-Lite-V1-V2-Flight-Controller-Phantom-1-2-Vision-p-991718.html?p=1511203511683201601F (http://www.banggood.com/Ublox-M8N-GPS-Compatible-with-DJI-NAZA-Lite-V1-V2-Flight-Controller-Phantom-1-2-Vision-p-991718.html?p=1511203511683201601F)

Mateusz:
I compiled the Next, I will poke arround and take a look at this.

Thanks

Title: Re: Set Failsafe with low battery
Post by: Mateusz on April 19, 2017, 07:40:16 pm

Quote from: zukenj on April 19, 2017, 02:23:16 pm

Mateusz:
I compiled the Next, I will poke arround and take a look at this.
Thanks

Obviously I assumed you are talking about autonomous flight modes which require all sensors functional and position hold working perfectly. Feature autoland for fast moving racer which usually relies only on gyro (sometimes also accel) is in most cases impossible (you need to stop vehicle usually moving/racing at very high velocity and hold position accurate enough and it would probably crash multiple times before slowing down).

To enable optional battery module you will have to go to configuration UAVBrowser (screenshot 1). This is explained on Wiki how to add voltage&current sensor by the way (for more details) and also how to calibrate voltage sensing accurately. If you want to calculate coefficients on your own as I tried, be aware that current sensor is reasonably accurate when pulling more amps (motors spinning) when it's low < 1A current flow, it might not match exactly your multi-meter if you would put it between battery. Maybe use default values from table and see if that works for you :) It does with AttoPilot sensor.

Enabling battery module will enable (disable earlier and greyed out options) for setting flight mode on battery voltage drop (screenshot 2).

Hope that helps :)

Title: Re: Set Failsafe with low battery
Post by: zukenj on April 21, 2017, 09:16:39 pm

Mateusz, Thanks for your reply.

I do have the sensor and calibrated, so the Battery module is enable. I guess that the Voltage alarm can be set in the UAVBrowser, I'll look in to it.

Thanks again