Copter-3.4-rc7 available for beta testing

Copter-3.4-rc7 is now available for beta testing through the Mission Planner’s beta firmware link (and perhaps
through other GCSs as well). Changes are below and also in the ReleaseNotes.txt. You’ll see it’s all bug fixes.

  1. Bug fixes, minor improvements:

a) more DSM binding fixes for pixracer
b) allow non-motor channels to move before safety switch is pressed
c) fix Bebop motor order
d) fix MAVLink system id for first few messages
e) fix throw mode throttle while rotating to level

This could be our final release candidate before the official release so all testing is greatly appreciated!


I just want to mention once in its own post… (I put it at the bottom of a different random post the other day…)
The Pixracer status LED doesn’t work. I know it’s nothing critical, and I can fix it w/ ISeries’ helpful post, but would be nice if it was working.

I won’t mention it again, and understand if it’s not going to make it into this release.


I have been trying to keep up with master although I have had to re-code my changes to work with the current master. I think they want me to submit a pull request but I am not comfortable doing that.
I have forked master and created a branch called “PixRacerOnboardLED” with the current changes in it.


APM Planner 2.0 is always in sync with Mission Planner for new beta updates.

What’s the status of the Compass Variance issue reported, can that now be resolved by disabling the internal compass?


Update this morning from rc6 to rc7 and fly goes well with quad + pixhawk + px4flow + terraranger.

What I saw that could be dangerous is that the copter arm via mavlink even with RC turned off !
That was not the case with previous version.

I’ve also have problems with guided mode from companion computer but as I’m experimenting it, it is probably not due to the code.

I’ve created a specific thread if needed : 3.4-rc7 copter arm via mavlink even with RC turned off (unconfirmed)

Quick report on RC7 flying over the weekend:

  • Tower 4.0 ok
  • all flight modes ok
  • Lidarlite (PWM) ok
  • Precision Landing, drifting issues, see other thread
  • ADS-B connected through Serial4: somehow works when I compare with flightradar24, but with veeery slow update rates in MP. A Plane track gets updated only every 2-10 seconds. No way to use this in real world.
    @rmackay9 is this normal?
  • another observation is that I get a constant stream of “disconnected”, “low RSSI”, “connected” messages on my OSD even while standing right beside the drone with the Rx and 3DR Radio. I did not see this with RC5 and earlier releases. Could not track any root cause for this.
    I am on a 3DR Ph1 with a 433 3DR radio attached


Thanks for testing. I’ve asked Tom Pettinger if he can look into the ADS-B stuff.

The OSD error very likely based on bad OSD behaviour in that the OSDs often don’t recognise the different system ids of various components of the system so they are likely getting confused between messages sent by the vehicle and by the radio itself. Why this is only appearing now is something we will need to look into… if you have a tlog that might hold some clues. Actually could you create a new topic? That’ll make it easier to track instead of getting mixed in with other replies.

@mtbsteve In regards to the ADS-B rate; these are rate-limitted now-adays (we don’t just pass through everything we get from the PING receiver (assuming that’s what you’re using).

We rate-limit because otherwise we would easily flood typical serial telemetry links in moderately congested airspace.

How many aircraft were being displayed on MP at the time? From that we can try to work out whether the rate-limiting might have been the issue.

I’ll see how I go with my quad here with a PING receiver attached.

I’ve just tested with my PING unit here and MAVProxy, and it all works as expected; I’m not in a heavily-trafficked zone, but when there is something I get frequent (1Hz) updates.

I’ve also just tried with Windows, MissionPlanner and a PING unit.

The single aircraft I’m seeing is updating at 1Hz.

If you are in a heavily trafficked area, you might consider tuning the ADSB_LIST_RADIUS parameter.

@mtbsteve Can you please retest the ADS-B 2-10 second update issue? Everything looks fine on our end, and the same code has been running on Plane for the last few versions without any problems. I suspect you were just getting intermittent signals from the remote aircraft - I suspect poor reception. Were you indoors? Can you provide any other details?

@peterbarker @MagicRuB thanks for your response.
I tested again today outside along with FW 3.4.1 and the Ping ADS-B receiver. I am connected through a 3DR radio to Mission planner.
I am in a low traffic area, and its never more than 1-3 planes crossing.
ADSB_LIST_RADIUS is set to 50000 (I assume this means 50 kilometers) At least I can see planes in that range.
ADS_LIST_MAX is set to 15 (I assume this means max 15 planes to track)
I tested outside in my garden.
Sometimes I get a 1Hz refresh, sometimes it clogs up and it takes 10 sec or more until a plane moves on (better say then jump over the screen)

Can it be a performance problem of my Laptop? (Its a 32bit 3GB RAM Celeron - not the fastest)

Here is a video showing the performance: