Autopilot Firmware Upgrade from 1.3.1 to 1.5.3

Small issue I discovered. Bare with me for a min while I try to explain everything.

My Solo is running 1.5.2 (just havent updates to .3 yet.) and Im driving thru the Rockies in CO. I pulled off to fly the solo at a nearby RC airfield and upon everything connected, and ready to fly, the motors wouldn't arm. The controller had a 0.7 HDOP and was "ready to fly". Neither Fly or Manual Fly would work. I was using an Nvidia Shield K1 tablet with the Solo APP. Each attempt to arm the motors resulted in the solo arm fail tone. I then tried Tower which connected fine. Upon an Arm motor attempt with tower, the solo arm fail tone continued but the error Tower produced was "Altitude launch ceiling exceeded". I was just over 9k' elevation near a lake.

I searched only for the parameter that controls this AFS and found one in the Pixhawk parameter list. Upon searching for the same (or similar) parameter with Tower in the solo parameters, nothing could be discovered. I then contacted 3DR support and asked them which parameter controlled this and/or which altitude is the ceiling. I never received this info but was told that I'd need to factory reset the solo and controller, perform the mandatory update, and then attempt again.

I don't want to revert FW back to an older version honestly, but the tech said that v1.5.2 was the cause of this symptom.

Does anyone know what the actual launch ceiling is? And which parameter controls this FS? And if it's even editable in Tower, or do I need another application to get to this parameter?

Thanks in advance.

PS, I ran searches for this, and read this entire thread. Could not find anything that way.

Hmm...interesting. I'll do some research and get back.
 
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carpy & dml931......

I live in San Diego & my solo has been flying fine here at sea level..........went to Mammoth Mtn last week ( elevation 8,600 ft. )....went to performed a flight ......everything boots up nicely.......I go to arm motors ( hold FLY button ) & nothing.....never did figure it out.......disappointing.......I didnt try to arm them manually ( throttle back & to the right )....
Can anyone helps us here.....???
 
@dml931 @Bilge
Ok, found it in code:
// check that we are below our launch service ceiling
if( barometer.get_pressure() < g.baro_launch_limit ) {
if (display_failure) {
gcs_send_text_P(SEVERITY_HIGH,PSTR("PreArm: Launch ceiling exceeded"));
}
return false;
}
Now just need to figure out where baro_launch_limit is set...
 
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So what you are telling us if the barometric pressure is less than whatever barometer launch limit.......we have a no go launch ....is that basically it in a nutshell.....

We can't be the first 2 to have discovered this .......unless this is peculiar to just F/W version 1.5.2
 
Yes, you're reading that correctly. If I were a betting man, I would bet that 3DR determined the air above X thousand feet is too thin for realiable and safe flight given the motor and prop combination. Not that it is necessarily impossible. But that it is at best too inefficient, and at worst dangerous. The altitude 3DR chose for that, whatever it is, would be as it applies to the heavier Site Scan version of the solo. So it is probably a little bit too low for the consumer version with a GoPro.
 
Based on what I see from commits, there is new parameter:
+ // @Param: GND_PRESS_MIN
+ // @DisplayName: ground level air pressure minimum
+ // @Description: If the ground level air pressure is lower than this value, then the copter will not arm. This is used to prevent takeoff at high elevaton locations where air density is insuffient for safe flight.
+ // @Units: Pa
+ // @Range: 50000 80000
+ // @Increment: 1000
+ // @User: Advanced
+ GSCALAR(baro_launch_limit, "GND_PRESS_MIN", 80000.0f),

So, you can try to find and adjust GND_PRESS_MIN, it might be that this parameter is based on sitescan weight.
 
Interesting...this is a parameter that's not included in master at all. I just got out and flew my hex for the first time in weeks and updated to Copter 3.4.5 and this parameter exists nowhere.

80000 is in pascals.

This site indicates altitudes for those readings. 80000 looks to be somewhere in between 6000 and 7000 feet. 50000 (the lower limit) is about 16,000 feet. Unless you're going to fly on mountains like that, I'd doubt you'd need to tamper too much with this setting.

I think 7000 feet might be the upper limit of what this bird can be flown at. Air might be too thin for it. I don't have any data to back that up, but atmospheric density in fractions at that altitude is about 3/4 of what it is at sea level.
 
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I generally agree with the logic behind 3DR adding this function. It is always wise to place software limitations on known flight envelope limitations. Though I have to wonder what prompted them to add it. Were there that many Site Scan users trying to conduct surveys from high in the mountains?
 
@dml931 @Bilge
Ok, found it in code:
// check that we are below our launch service ceiling
if( barometer.get_pressure() < g.baro_launch_limit ) {
if (display_failure) {
gcs_send_text_P(SEVERITY_HIGH,PSTR("PreArm: Launch ceiling exceeded"));
}
return false;
}
Now just need to figure out where baro_launch_limit is set...

here is some minimal discussion and background to that commit and which files were changed:

Add air pressure lower limit to pre-arm checks by priseborough · Pull Request #268 · 3drobotics/ardupilot-solo · GitHub


I generally agree with the logic behind 3DR adding this function. It is always wise to place software limitations on known flight envelope limitations. Though I have to wonder what prompted them to add it. Were there that many Site Scan users trying to conduct surveys from high in the mountains?

It looks like they changed it in order to allow a bit more flexibility to the prearm-alt-restriction which was deleted... maybe some one with approved access can share the discussion thats hidden here;
Atlassian Cloud
 
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Well, I was just disappointed when I was going helicopter skiing at 11,000 ft that I could not arm my drone when jumping off the cornice......j/k...I could not arm at 8,600 ft....when my feet & drone were planted firmly on the ground

There is a a lot of pretty places that can not be filmed if the limitation is around 7,000 ft or so......oh well......
 
Well, I was just disappointed when I was going helicopter skiing at 11,000 ft that I could not arm my drone when jumping off the cornice......j/k...I could not arm at 8,600 ft....when my feet & drone were planted firmly on the ground

There is a a lot of pretty places that can not be filmed if the limitation is around 7,000 ft or so......oh well......

I'm sure 3DR built in a factor of safety, so if you're willing to accept the risks, eliminate the safety factor and pair it with a motor upgrade, larger props and reduced payload, you could quickly increase the flight envelope.
 
I'm on 1.5.3
A little confused if I should be concerned with the possible ESC issues here.
Seems that people here are also not confirming if it's truly an issue or not.
When I flashed it I was either told or I read that the accelerometer needs to be re-calibrated.

I calibrated both accel and mag on site before flying after the flash.

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I'm on 1.5.3
A little confused if I should be concerned with the possible ESC issues here.
Seems that people here are also not confirming if it's truly an issue or not.
When I flashed it I was either told or I read that the accelerometer needs to be re-calibrated.

I calibrated both accel and mag on site before flying after the flash.

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at this point in time, nobody here is fully equipped to confirm whether or not an issue exists with any certainty. we can only state with full confidence that you are flying 1.5.3 at your own risk. but you are also flying 1.3.1 at your own risk. you can reset the mot_thst_max parameters to the legacy value, of course perhaps that has it's own negative ramifications? you need to understand the risks and fly within your level of experience and comfort.

Autopilot Firmware Upgrade from 1.3.1 to 1.5.2
 
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Based on what I see from commits, there is new parameter:
+ // @Param: GND_PRESS_MIN
+ // @DisplayName: ground level air pressure minimum
+ // @Description: If the ground level air pressure is lower than this value, then the copter will not arm. This is used to prevent takeoff at high elevaton locations where air density is insuffient for safe flight.
+ // @Units: Pa
+ // @Range: 50000 80000
+ // @Increment: 1000
+ // @User: Advanced
+ GSCALAR(baro_launch_limit, "GND_PRESS_MIN", 80000.0f),

So, you can try to find and adjust GND_PRESS_MIN, it might be that this parameter is based on sitescan weight.
Interesting...this is a parameter that's not included in master at all. I just got out and flew my hex for the first time in weeks and updated to Copter 3.4.5 and this parameter exists nowhere.

80000 is in pascals.

This site indicates altitudes for those readings. 80000 looks to be somewhere in between 6000 and 7000 feet. 50000 (the lower limit) is about 16,000 feet. Unless you're going to fly on mountains like that, I'd doubt you'd need to tamper too much with this setting.

I think 7000 feet might be the upper limit of what this bird can be flown at. Air might be too thin for it. I don't have any data to back that up, but atmospheric density in fractions at that altitude is about 3/4 of what it is at sea level.

Found that parameter setting with tower, thanks a lot for this info. On my way
back thru the rockies Thursday I'll attempt another flight at that same location after changing that parameter to 69681 (which calculates to around 10k'). Right now I'm in UT for a few nights and the current elevation is around 4k'. Will report back soon my findings.
 
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Does anyone know how to easily get and flash back to 1.3?
Mainly what I am asking is where to get a copy of the original firmware.
Maybe it is still setting in the file structure and needs to be copied to the /firmware flash directory?
I'm having a rough time deciding whether to go back or stay on 1.5.3 :)
I'm also not exactly sure how to flash it back.
Thanks!
 
Does anyone know how to easily get and flash back to 1.3?
Mainly what I am asking is where to get a copy of the original firmware.
Maybe it is still setting in the file structure and needs to be copied to the /firmware flash directory?
I'm having a rough time deciding whether to go back or stay on 1.5.3 :)
I'm also not exactly sure how to flash it back.
Thanks!

According to my conversation with 3DR support today, you have to factory reset both the solo, and the controller. Delete the app and reinstall forcing the 1.3 update again.
 
According to my conversation with 3DR support today, you have to factory reset both the solo, and the controller. Delete the app and reinstall forcing the 1.3 update again.
Yay! (not).
I may have been a little to hasty to upgrade it. :)
 

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