Copter-4.5.3-beta1 is available for beta testing

Copter-4.5.3-beta1 has been released for beta testing and can be installed using MP or QGC’s beta firmwares link or it can be directly downloaded from

The changes vs 4.5.2 are in the ReleaseNotes and copied below.

  1. Board specific enhancements and bug fixes
  • correct default GPS port on MambaH743v4
  • added SDMODELV2
  • added iFlight Blitz H7 Pro
  • added BLITZ Wing H743
  • added highres IMU sampling on Pixhawk6X
  1. System level minor enhancements and bug fixes
  • fixed rare crash bug in lua scripting on script fault handling
  • fixed Neopixel pulse proportions to work with more LED variants
  • fixed timeout in lua rangefinder drivers
  • workaround hardware issue in IST8310 compass
  • allow FIFO rate logging for highres IMU sampling
  1. Copter specific changes
  • fixed speed constraint during avoidance backoff
  • zero D_FF during autotune twitch

There are two potentially serious bugs that I’ve highlighted above and while they are exceptionally rare we’re keen to get this beta out as soon as we’re sure it’s safe so all beta testing is greatly appreciated.

To provide some more info on the two bugs

  • if a lua script failed in flight (e.g. produced an error) it could actually cause the main CPU to hardfault and the vehicle would crash. This doesn’t happen every time the lua script fails though, just in rare cases with unlucky timing
  • the avoidance backoff could cause the vehicle to descend at a very high speed to get under the altitude fence. This is really only possible if home is moved to a low altitude that forcdes the vehicle to be suddenly above the fence.

Thanks in advance for testing!

Hi! Can we have the following feature in the next beta?

Many users have the Siyi A8 mini gimbal and being able to set FPV mode would be very important.


Hi @Andre_Freitas,

That PR is included in 4.5 but it doesn’t quite allow setting the Siyi gimbals to FPV mode. We need an additional change to expose this to the user. There’s an item on the to-do list here to add FPV mode support.

1 Like

Oh I did not know that. Thank you for the information. Then I will be waiting patiently for that feature. I think it will be very important for a lot of users.

I forgot to say that I also identified a bug with SIYI A8 that I think is not related to this release but might be happening since the begining of siyi integration in ardupilot.

Basically if I use the SIYI modified QGC app to use touchscreen sliding controls to move the gimbal everything works fine if I don´t set the MNT1_TYPE parameter. However, as soon as I set Mount type as SIYI the touchscreen sliding controls stop working correctly. I think it might be related to some problem in the siyi drivers

Hi @Andre_Freitas,

OK, thanks for the report. If MNT1_TYPE is not being set then I think the AP code is being bypassed completely. AP wouldn’t have any control over the gimbal so it would be up to Siyi to investigate that.

By the way, we have a new version of QGC 4.4 which is undergoing beta here!

Yes but the siyi controls only start having problems as soon as MNT1_TYPE is set and AP code is running. Thus, I don´t know if it is a Siyi problem or ardupilot problem

Yes, I know. I am running my custom version which is a merge from QGC stable 4.4 and SIYI modified QGC

Hi @Andre_Freitas,

We’re trying to reduce the need for OEMs to write their own bespoke ground stations to control the gimbals.

The QGC 4.4 that is undergoing beta testing is an official piece of software from the QGC team. I can help with that, but for Siyi’s modified QGC, I think you’ll need to talk to them.

1 Like

I flew this yesterday on my Redback Spider (Cube Red on an EDU-650) and got a couple of Internal Error 0x20000000 during a mapping mission. I’m using the Siyi A8 mini although I don’t know if that has anything to do with it.

This may or may not be a pre-existing problem, but I have flown this mission before and didn’t see the problem.

Here’s the log:

1 Like

Hi @timtuxworth,

Thanks again for your testing and feedback. I’ve added this to our 4.5 issues list under “confirmed issues”.

The internal error is coming from this line in the SCurves library which means we must have some combination of waypoints and WPNAV_xxx parameter values that we weren’t expecting.

As you suspect, this error is probably not new to 4.5.3-beta1 but it’s still something we should fix because it’s certainly annoying to have this appear and just as importantly it means something unexpected happened.

FYI @Leonardthall