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Aug 04, 2015, 03:12 PM
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Thread OP
Quote:
Originally Posted by HuguesD
Hello,
I have Orange RX 1W modules for a few months laying in my drawer. Today I did a firmware upgrade on both to try it out as telemetry link only between mission planner and Pixhawk.
I got succesful firmware upgrade with the URLS upgrader.
I flashed one as TX, the other one as RX.
I checked many time the correct RX/TX wiring on both sides (and it works flashing the modules anyway).
When I plug both I get the two leds flashing very rapidly on both units. If I plug the TX only on the PC side, it beeps (to alert it does not see the RX, I suppose).
I configured Serial1 at 19kbauds in mission planner.
But then when I try to connect, it just times out.
What did I miss ?
Everything looks good :
- all LEDs flashing quickly (30 times per second)
- TX beeps if the RX is not powered up

As 3D_World suggested, check that MP is connected at 115200, and serial1 is at 19 (the parameter value to set is 19, not 19200)

Then, most importantly, check you're using version 1.3.15 of Mission Planner.

I still have to investigate, but it doesn't work with more recent version, probably something to destroy non 3DR radios
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Aug 04, 2015, 04:37 PM
Registered User
Quote:
Originally Posted by flipflap
probably something to destroy non 3DR radios
Not going to happen

By the way rssi from RX working great now on rxrssi option(Mission Planner)
I am not able to see rssi on Tower at my Nexus but i think is only active via mavlink(if you can confirm that it will be good to know)

So any info how to increase power?

I did a range test with a dummy load on the TX and normal antenna from Dragon Link on RX that i have here.
15 meters with no to much of failsafe.

But due to the fact that i done almost everything now with your help ofcourse how can i increase the power

Thx
Aug 04, 2015, 07:02 PM
Just call me Justin.
Quote:
Originally Posted by 3D_World
Not going to happen

By the way rssi from RX working great now on rxrssi option(Mission Planner)
I am not able to see rssi on Tower at my Nexus but i think is only active via mavlink(if you can confirm that it will be good to know)

So any info how to increase power?

I did a range test with a dummy load on the TX and normal antenna from Dragon Link on RX that i have here.
15 meters with no to much of failsafe.

But due to the fact that i done almost everything now with your help ofcourse how can i increase the power

Thx
How far do you wanna go???

with a couple nice ant. you should be able to go 20-30km.
Aug 04, 2015, 10:09 PM
Registered User
Thread OP
Quote:
Originally Posted by 3D_World
Not going to happen

By the way rssi from RX working great now on rxrssi option(Mission Planner)
I am not able to see rssi on Tower at my Nexus but i think is only active via mavlink(if you can confirm that it will be good to know)

So any info how to increase power?

I did a range test with a dummy load on the TX and normal antenna from Dragon Link on RX that i have here.
15 meters with no to much of failsafe.

But due to the fact that i done almost everything now with your help ofcourse how can i increase the power

Thx
Good news that you got it working.

The RSSI from RX is visible in mavlink if you connected it to APM, and the RSSI from TX will be visible on your analog meter. The two values should be about the same.

Here's how to increase the power :
https://www.rcgroups.com/forums/show...postcount=1496

I've updated the FAQ page regarding this modification :
http://www.itluxembourg.lu/site/hobb...z-modules-faq/
Last edited by flipflap; Aug 04, 2015 at 10:23 PM.
Aug 05, 2015, 05:04 AM
Registered User
Quote:
Originally Posted by jt41time
How far do you wanna go???

with a couple nice ant. you should be able to go 20-30km.

http://www.flytron.com/openlrs/297-7...s-openlrs.html

Don't worry

I have one of those for close distance.

Thank you flipflap your work is great and building your project it feels like you bit the system some how my friend.

I forgot to say about RSSI.Yes it is visible on OSD and Mission Planner but not visible if you are using Tower via BT module on a Android device.
Last edited by 3D_World; Aug 05, 2015 at 05:14 AM.
Aug 06, 2015, 07:29 AM
Registered User
Problem with downloading parameters is caused by FW or mission planer. After the flash to copter FW3.2.1 parameters can not be downloaded through bluetooht in mission planer or in droidplaneru (or tower). Have you ever solved? I do not know if it caused flash FW or update droidplaneru.
Aug 06, 2015, 09:44 AM
Registered User
Thread OP
There's a similar issue with Mission Planner above 3.1.15

Probably the same thing with DroidPlanner, but I don't know since which version exactly.

I'll check that too, but for now I focus on completing the release.
Aug 06, 2015, 09:45 AM
Registered User
Thread OP
Quote:
Originally Posted by 3D_World
http://www.flytron.com/openlrs/297-7...s-openlrs.html
Thank you flipflap your work is great and building your project it feels like you bit the system some how my friend.
Thanks !

As you're using Tower on Android can you confirm if everything works as expected ?
Aug 06, 2015, 10:20 AM
Registered User
Tower has the same problem. Telemetry is function. Download parametre is problem.
Aug 06, 2015, 12:01 PM
Registered User
delete
Last edited by moti; Aug 06, 2015 at 02:20 PM.
Aug 06, 2015, 01:32 PM
Arrière pays Niçois
salience's Avatar
Photos of my DIY groundplane antenna. AS expected (by now) flipflap is on to something terriffic with this type of antenna. See the 3 SWR graphs I made comparing the groundplane, a supposedly "tuned" commercial dipole, and a genuine Diamond whip. The groundplane has a feature you can't see - a sleeve balun inside the plastic support tube. It is simply a 1/4-wave brass tube surrounding the coax and soldered onto the shield at the base end (not at the SMA connector). The radiator and legs are thin brass tube, 2mm ID I think, legs about 5% longer than the radiator. I chose this since brass tube is quite stiff, and straight to start with (unlike wire) and the size used fitted conveniently over the SMA adapter center pin for soldering, and through the 4 holes of the bulkhead mount of the SMA connector. All weatherproofed with shrink tubes and hotglue melted smooth with a heatgun. This was supposed to be just a test run, but the great SWR has made further trials unnecessary. It will go atop a 6-meter mast. The radiator was intentionally a bit long to start with, and had a SWR minimum at about 402MHz. I clipped off several short (1-3mm) pieces of the radiator until I got the SWR shown in the graph. As you can imagine, quite pleased with the result! Measurements made with RF Explorer and Signal Generator as per the "how-to" at their website. And another big thanks to flipflap!
Last edited by salience; Aug 06, 2015 at 01:38 PM.
Aug 06, 2015, 03:02 PM
Registered User
Thread OP
Quote:
Originally Posted by jamesgsf
Tower has the same problem. Telemetry is function. Download parametre is problem.
OK, notice it's only with Mission Planner versions above 1.3.15, so probably for Tower it will work with older versions.

I checked with APM Planner and it works fine with the latest version.
Aug 06, 2015, 03:19 PM
Registered User
Thread OP
Quote:
Originally Posted by salience
Photos of my DIY groundplane antenna.
Wow, the graph with SWR < 1.1 says it all, that's a great antenna !

Would you mind sharing the plans ? I'm adding your photos to the user contributions page here.

The one I'm using works fine too, and you made me think the tube is maybe also a balun as on your antenna.
Aug 06, 2015, 04:54 PM
Registered User
Thread OP
The firmware is the same for TX and for RX, it detects automatically if it has to be the TX or the RX (based on PPM detection).

This simplifies the firmware programming, you don't have to select if it's a TX or RX, it's the same firmware.

I've added morse code support, for example if the firmware detected it has to be the TX, it says 'TX' in morse. Maybe some other short error messages will be added.

Another new feature is in the ULRS configuration, it lists all available COM port, and automacically identifies the ones with ULRS, and their baudrates.

And then the next feature is cool : it shows in real time the RSSI for each channels, but also the noise level. The noise level is measured in the short time between two packets. From this, the SNR (signal to noise ratio) is displayed in real time for each channel.

The advantage is that the 'good' (high SNR) and 'bad' channels can easily be detected. This will lead to other future features, such as dynamic channel selection.

The SNR is the only value really interesting for the users : rather than having to rely on an RSSI level, it computes the difference between the RSSI and the background noise. And this for every channel in real time.

Yes I know I said it twice, it's late

OK, and a third time, look at the attachment. Which one is the worst channel in your opinion ?

Looking at the RSSI, you might say channel 0 or 5 have the lowest RSSI.

But that's not the full story : the noise level is much worse for channel 5.

The channel 5 is on a frequency where there's a slight interference (as can be checked on the spectrum analyzer). You can see the noise level which is higher than for other channels. But the interesting value is the SNR, which shows that given the current distance, we still have a lot of room. But ideally it would be better to replace the channel 5 by another one.

So the SNR gave immediately the correct information about each channel quality, including the background noise / interferences.
Last edited by flipflap; Aug 06, 2015 at 05:02 PM.
Aug 06, 2015, 06:03 PM
Arrière pays Niçois
salience's Avatar
The plans are basically the document you referred me to awhile back on building a GP antenna,
https://www.arrl.org/files/file/Tech...df/ab18-16.pdf
plus a few links on sleeve (bazooka) baluns such as
http://www.antenna-theory.com/definitions/bazooka.php

You can see how I soldered it together in the photo. The balun is soldered to the shield of the coax at the lower end and its top is just short of the SMA nut. Not touching of course. Can't show you a photo of that without disassembling...

But my final resulting lengths after tuning are not in agreement with the GP calculators!

the lengths are
radiator 145mm
radials 182mm
these are measured from the outer tip to the center of the antenna assembly.
sleeve balun 161mm

My radiator did start out at over 161mm but the VSWR minimum was then about 400MHz. Successive trimming of the radiator and measuring according to the procedure at
http://j3.rf-explorer.com/43-rfe/how...on-return-loss
got it down to the 145mm figure. Curious. Possibly the balun plays a bigger role than suspected here. I didn't see any links showing a GP antenna with a sleeve balun, only regular dipoles. And/or the long radials may have an effect.

I'm going to check into this over the next few days and I'll report back. I'd have my doubts about such a good VSWR had I not compared the GP to the Diamond and dipole under the exact same setup. I think we can pretty much trust the RF Explorer/Signal Generator instruments, and the minicircuits coupler used. And note this was all done in the shop with various large and small hunks of metal in the vicinity (like a big band saw) so I really need to do further tests with the antennas out in the open.

Quote:
Originally Posted by flipflap
Wow, the graph with SWR < 1.1 says it all, that's a great antenna !

Would you mind sharing the plans ? I'm adding your photos to the user contributions page here.

The one I'm using works fine too, and you made me think the tube is maybe also a balun as on your antenna.
Is that tube connected (only) at the base shielding? It looks like it's connected to the part from which the radials depart.


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