Hi thanks for your reply!
Meanwhile I made some changes, now it’s about 0.750-1 kb/s but I will make some tuning based on your advices.
serial1_protocol=2 it’s done
change BRD_SER1_RTSCTS=0 Do you think it’s not neccesary to use RTS/CTS (they are enabled on both radios now)?
Do you provide “clean” external power - I will try it!
Lower your air_speed to 64 to both radios - Now it is 100 it was 64 but I will try again with 64.
change duty_cycle to 100 - when I change to set the duty cycle from 10 to anything else it does not connect. or you mean 10 = 100% ?
change SR1_PARAMS = 10 It is now 50 I will try it.
ensure your antennas are at 90degr for both sides for diversity to work - it’s done
If you use the monopole antennas on the airside, ensure 90 deg placement and proper usage of some duct tape aluminum foil to act as ground plane. - seems to be a good idea thanks
Mandatory!!! Twist the cables and might use ferite
Mandatory
Correct i mean 100%
50 is overkill,
google the Lamda for 868MHz and apply the correct area needed (no less no more), less wont do anything, more might make it more prone to noise. Rule of thump is minimum 1/4 wave length radius (about 3inch radius circle for 868)
I use these settings with the RFD900 and with TXMODv2, you have to set your SERIAL1_BAUD=115
RFD868 should work the same as the 900’s. Duty Cycle should definitely be 100 unless there’s a restriction in your region.
I also use SBUS for the RC control via TXMOD (GPO1_1 SBUSIN and GPO1_1 SBUSOUT), not shown in the above settings. It’s much better than PPM (the ordinary R/CIN and R/COUT)
You can use RTS/CTS after you’ve got everything working well with them disabled.
Wish I could use your settings. Unfortunately here in EU we are much more limited. The duty cycle is limited in this firmware to 10 which means 10%. I can use only one channel in “# of channels”. When I set air speed other then 100 it is slower or not able to connect. The ECC option was also removed from firmware earlier. I could not use 38k or 115k baud rate (also satted in mission planner serial1 baud).
Hi I have tested everything that I could with various settings. Also between two equal modems and between a modem and the txmod.
Lower your air_speed to 64 to both radios . I can’t the both of my modems aren’t able to set this. I get an error message and the old value is bringed back. But I can set this value on TXMOD. The difference is my modems are 868ux EU and TXMOD includes 900X which is a much better device I guess.
change duty_cycle to 100 to remote radio - I can’t it is limited in firmware to 10.
change SR1_PARAMS = 10 - it’s done
This is the maximum I can reach all other settings were slower or did not work at all.
Krisztian, do the math. with 100kbit/sec air rate at 10% duty cycle you will get a 10kbit/sec effective air rate. divided by 8 is 1.25 kbye/sec, but this is still the air rate. Deduct the overhead and you arrive at 1kbyte/sec. Which is about the same as a 9600bps modem.
The initial parameter loading time Stilo takes several minutes despite almost 5 times faster then before.
The one million dollar question is, why does it poor results using 200 kbps air rate which also the factory default…
Dimitris Stefanakis via ArduPilot Discourse <noreply@ardupilot.org> ezt írta (időpont: 2021. dec. 11., Szo 9:25):
Faster than before seems we are get into something,
Still iam worried by the difference in rate/freq setting as well as the enabled RTS/CTS. You may also try
If you do these two checks along with all the other mentioned before and not getting your params in a few seconds, then it’s most probably a faulty hardware. I have never seen this behavior with RFDXXX series of any kind.
As a last resort, ensure both ends have latest and same firmware and restore default values.
I tried uploading the latest firmware onto my set of 868ux radios and got this result. No other changes before that seemed to make a difference. The connection so far seems good enough to read attitude changes with 1-3s delay, can read /write missions and do sensor calibrations. Will see how it performs in the air soon hopefully.
Hi - I believe I achieved 2 kbps once I loaded the correct firmware onto the radios. That was my issue IIRC. I ended up using the 900x models and the txmod unit with my Taranis. It all worked quite seamlessly in the end.
I am actually in Canada - the 900x handled the mavlink connection well. I did a range test to see how the RSSI dropped off but don’t have that on hand. I am not sure to be honest what the bit rate should be. I stopped troubleshooting the radios once I got to that point and it was working reliably.
but I will make some tuning based on your advices.
