Parameter Loading to QGC and MP Very Slow

The loading of parameters can take a very long time over telemetery. To debug a little, I forwarded the messages over UDP and monitored the message rates at start up. At first PARAM_VALUE comes in real fast, 50Hz-100Hz for a few seconds. Then, all the other messages turn on, and it slows down to <5Hz. And ‘takes forever’ - anywhere from a couple minutes to seemingly never. This makes it seem like the radio is capable of transferring at sufficient speeds, but software is slowing things dow.

One other weird symptom is that no matter how low I set the other message rates via SR1_ parameters, the parameters still slow down about the same amount.

Is there maybe an option to delay starting of the other messages until the parameters load? Or radio settings I should adjust?


pixracer r15
copter 4.0.7
holybro 915MHz 500mW

I don’t know how the holybro radios will cope, but with genuine RFD900x radios we successfully use these much higher throughput settings, range will be decreased:
Baud: 115200
Air Speed: 125
Duty Cycle: 100
Max Window (ms): 80
Mavlink: ON or Mavlink - not Low Latency
ECC: (none)
RTS CTS: (none)
Op Resend: (none)
AES Encr: (none)

Apart from the high baud rate, the Window ms setting is somewhere between default and low latency values. I couldn’t get the low latency settings to work reliably.

We can effectively download log files over radio!

Thanks. I am shooting for about 2km range, but haven’t yet experimented with that.

I tried setting the internal speed to 115200, but then neither QGC or MP would connect. Neither would connect to the radio at all or allow firmware. Had to connect via putty and use the AT commands to get it back to 57600. Maybe I have to tell QGC/MP somewhere to use 57600. Could not get the flow control or ECC to work with the GCS either. Anyways, I guess that could help some, but it doesn’t really seem like the base issue. In the first few seconds, I’m getting great rates, then they go down…

I just switched to the MRO radios, and they so far are consistently much faster. Based on 5 consecutive QGC start ups. A couple including power cycles.

I got the holybros hoping the 500mW version would get me more range. But, this long load time is a real pain to deal with. Am I doing something wrong with them? Overheating them? Maybe keeping them too close to each other on start up?

OK, brought ‘Tx power’ down from 20 to 5. Have no idea what that means, but huge change. I assume I’ll want that power when the thing is far away though. Is there an auto power management? Or a way to change in flight?

For now, I guess I’ll just keep bumping it up until I hit a wall.

I guess the radio is maybe ramping up the power in the first few seconds as to why it gets worse.

On another note, is there a way to tell QGC to cache the vehicle parameters - i.e. assume they don’t change so I don’t have to grab them every time. It doesn’t need 99% of them for most operations.

TX power of 20 (dbm) would normally be 0.1 watt, but if they’re supposed to be 500mw radios then who knows… Probably all just extra noise :laughing:
The dbm are logarithmic so 17 would be about half of the normal/default power, and 10 would be about a 10th of the default power. 5 is about 30th.

So any other ideas on how to work around this - again I assume I’ll want the power at longer range. So, any way to:

  1. Reduce the tx power while on ground?
  2. Cache the vehicle parameters so they needn’t load every time QGC starts?

Preferably without code changes…


I have the same issue. I identified, when I do not use the telemetry (Yaapu) the speed does not slow down.



never ever could I be so patient because for me it takes x times longer than compared to USB download (and x > 10 :roll_eyes: )
and no matter if it’s holybro v3 or a WLAN module


it’s running for 7 minutes now… :sleeping:
MP 1.3.74