Mavlink Telemetry problem. Parameter upload is very slow

I have an issue with very slow transferring speed. The FC is HEX Cube Orange. I’ve tried the telemetry with both RFD900ux and crossfire. Ground control software is mission planner. Parameter loading is very fast on USB but when I want to connect PC via telemetry it’s very slow, even in the room. Usually around 1kb/sec - parameter loading takes almost 10 minutes. The signal quality is usually over 85%. RX TX lines are fine. I’ve tried several baud rate options (settings were done on both sides and on radios aswell). What is the optimal transfer speed in air (in case of short range)?

telemetry radios are tuned for range rather than speed, if you want fast wireless then you should look at something like wifi.

It’s ok but what is the acceptable speed in kb/sec? After every battery replacement should I wait 10 minutes to start a mission (my possibilities are very limited before the parameter list is loaded)? Sorry I’m noob at ardupilot I don’t know what is normal. I’m more experienced at DJI and betaflight based drones.

If you don’t need to change parameters you can connect by using Ctrl+T in mission planner, it will connect without loading them.

Thank you! I will do so. Otherwise which GCS is prefered for quadcopter operations QGroundControl or MissionPlanner?

mission planner is more feature rich but qground control is sleeker and more modern just depends on what you prefer.

Make sure you are using the most recent beta version of Mission Planner and 4.1.2 firmware on your vehicle. That may help.

Using ctrl+T is a workaround, i think he should find the reason why it takes 10 minutes to download params, it should take few seconds.

A proper configured RFD900ux should be very fast.

Take a look at RFD900 and RFD868 threads in this forum. Mine run great even with extra Yappu telemetry and AES 256 bit encryption!

Make sure Tx and Rx are connected properly on both radio’s, I had a similar issue: RFD868+ "getting params 1" never finishes? (Solved) - #6 by Graham_Dyer
Otherwise try enable rts/cts on the radio or also try change sr1_params to say 100.

You mean that RFD900 works?? Wow i wouldn’t have ever imagined!!!
I must remember to never take the obvious for granted.

hello, have you check the Stream rate parameters yet? Please post the param file or .bin log file, so I can check these. However, it guess it may be a problem.

Hi! Thank you for help! Could you please explain what do you mean on Stream rate parameters. I have been looking for them in ardupilot documentation but could not find.

Hi! Electronically it’s fine, I can see the rx and tx bytes are also incrementing. But the speed…

Here is the documentation:

Here is parameters documentation:

Google “arducopter stream rate parameters” gave me those links. :stuck_out_tongue:

Look for a param named:

SRX_PARAMS (X is the serial port you are using for telemetry).

You can try increasing it to 50 and see if it makes any difference.

For example if you have telemetry on serial 1 look for:


and increase it to 50.

You can find all params in MissionPlanner---->config---->full parameter tree (scroll down to SR0 SR1 SR2…)

Hope it is clearer than some “i have it longer than yours kind of answers” :slight_smile:

Thanks it’s clear now! I’ve tried set SR1_PARAMS to 50 but no effect. I use the TELEM1 connector with factory cable to interfacing cube orange with RFD900 (precisely RFD868ux). Based on the manual it is SERIAL 1.

Ok thanks for being so detailed I’ll try to following you :slight_smile:
Here are my relevant parameters below(I still have connection it works but very slow). I’m trying two different options as you will see. I also made a try with crossfire from my FPV drones with micro TX v2 and nano RX but it was also slow.


Setup no. 1.

GROUND: TX MOD (a factory made RFD900based radio module inserted to my Radiomaster TX16S connecting to PC via WIFI in AP mode using UDP protocol on port 14550)

result 1:image
Setup no. 2.

UAV :same settings
Ground: RFD868ux modem with usb serial cable using serial port in mission planner.

result 2: almost the same

Hi sadly the SR1_PARAMS setting did not solve the problem. Here is my settings filerfd900_211209.param (21.8 KB)

I think I make a chance with software upgrade now. It’s the next step.