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- เผยแพร่เมื่อ 27 ส.ค. 2018
- More tests with different antenna: www.iforce2d.net/loratest2/
www.iforce2d.net/sketches
www.iforce2d.net/loradataviewer/
www.airspayce.com/mikem/ardui...
www.airspayce.com/mikem/ardui...
Ra-02 modules (Banggood): goo.gl/q3G552
433MHz antenna (Banggood): goo.gl/ztgWLf
gazette.govt.nz/notice/id/201... - บันเทิง
Trying the "long range, slow" ModemConfig settings again now, the problem is not that no packets are received, but that the content of the packet is all zeros. Reducing the message size to 4 bytes did not help. I also tried the suggestion by "ryanrs" here, also with no change: lowpowerlab.com/forum/general-topics/issue-with-lora-long-range-modes-and-rfm95rfm96/
What the hell is going on?
ok, finally figured it out - the radio stuff had been working fine and it was just a mistake in my sketch. When using the slower transmission, it takes about four seconds to send the fairly large message I'm using. Since the transmission is blocking, none of the data from the GPS can be processed during the send. After the send, some of the bytes from the GPS can be processed, but only what is in the buffer which is rarely enough to make a full NAV_PVT message. Then it proceeds to send another radio packet and incur another four second wait, and so on. So processGPS had never been succeeding, and I was simply sending a message full of the zeroes that the "loc" struct had been initialized with. The solution was to only send a radio packet after a successful processGPS call.
I’m glad you worked it out.
Hi, I was wondering if you were planing to make another video explaining this, using the long range and the solution to the problem?
I added a link in the description to some more test results.
Can you give an example of the length of the packets you're sending ? Was setModemConfig(Bw125Cr48Sf4096) working all along ?
I got 200km on ground with an Rfm95 LoRa module on 868MHz. And in a balloon they got 700 km. 433MHz should even be better because lower frequency has less loss. It is documented in one of my LoRa videos. Most China antenna I measured are for completely different frequencies.
" is documented one of my LoRa videos" A link would be most helpful....
This one I think: th-cam.com/video/adhWIo-7gr4/w-d-xo.html
Andreas wouldn't your other video about point to point connection be a better comparison here?
th-cam.com/video/WV_VumvI-0A/w-d-xo.html
Looks like you confirmed around 500m range for that case.
Since he didn't answer I ll come up with a possible explanation :)
first of all back then he used the same crappie antennas.
But the reason why he made the measurements at around 500m is because of safety issues (I think!) . Here in Germany you must stay line of side with your quadcopted (by law).
If the signal was at 500m at is maximum he wouldn't get any packages after he went behind trees or buildings.
So that's why i think you could go further.
with 2 tt-go lora32 board 868Mhz, one tx and one in rx , i got 68 km last week (line of sight), and it has only 2Dbi antenna, so definitely you can achieve much more
Hi iforce2d- Nice test, thanks for doing that. I’m using LoRa in an urban environment with many houses between the transmitter and receiver, and getting consistent range of 400 meters. So I think your range will improve dramatically once you figure out how to change the configuration to high power.
Interesting video! Nice to see videos about LoRa technology.
Awesome video Chris! I've gotta give this a go!
Very interesting what you were able to do with it. That java app overlaying the data over a map is just incredible. Great work thanks for sharing.
JavaScript. If you look at the page source it's actually less than 200 lines total, including HTML and all. Pretty neat what you can do in a browser these days.
What a great gideo. Your web page scripting skills really steps up the quality for the viewers!
You are a legend mate! Thank you.
Excellent video, very informative, many thanks.
We looked at LoRa at work for a project, these ranges seem far shorter than what we looked at when we looked at setting up a LoRa gateway?
As a lot of others have commented I think there might be a lot of room for improvement on the antenna side.
But thats a sweet setup and location for testing it so look forward to seeing more about it!
QUIT MESSING AROUND AND FINISH YOUR PLANE lol
your videos are always right on par keep up the great informational content
Thanks for linking the antennas
few things you should keep in mind:
-your antenna orientation was not the same between modules
-most antennas are not tuned for the freq. they sell them for, so you aren't able to transmit full power you have set
-you were on 25mW or less
Am involved in rolling out gateways in Norfolk UK. One of our members got 226km across to Holland. I regularly get up to 10km on my home gateway. I am very interested if lora could be used to give a remote robot GPS waypoint data.
Well, very interesting! Also, you might want both antenna vertical (instead of horizontal in the plane?) to get the same polarisation or get a better tuned antenna as it could increase my 433 telemetry range up to twice to triple the distance.
In my experiments with the 2.4GHz stuff the orientation never made much difference, so I didn't worry about it here. With a 14 element yagi it did make a huge difference, but that was the only case. Are you saying the polarization got you that range improvement, or the better tuned antenna did?
iforce2d Its the tuned antenna, sorry I'm not making it clear : ). I got a pair that cost me (equivalent of) $30, its a hand made local product called ORT antenna (433mhz version), quite expensive but compact and worthed. The antenna placement can increase range, but to my experience not that far though, but did increase.
Fantastic video thanks so much. I've been looking at lora for telemetry for some time, but it seems very difficult at this stage. It's just a huge pity you went through all that trouble but your antenna orientation was not matching. I know what you mean about 2.4 - but I suspect your 433 antennas are higher gain (more of a donut and less of a sphere) and therefore orientation is important. Looking forward to more on this topic, please!
TBS crossfire and the FrSky 900MHz system also seem to use these modules (or more the same chip that sits under the shield)
As the name suggests, these systems operate at 900 Mhz. This LoRa module works at 433 Mhz.
This specific one in the video, yes, but there Lora chips support a wide range of frequencies.
What do they use them for? If I understand it correctly LoRa would be way too slow for radio control.
At least the chips seem to be in there
www.rcgroups.com/forums/showpost.php?p=32943780&postcount=157
"Programmable bit rate up to 300 kbps" interesting.... looks like even this one I have is like that too.
Most "radio modems" like this will trade speed for distance. Even the standard 900/433 SiK telemetry radios that Ardupilot/PX4 use can be configured for different "over the air" baud rates. The default for them is 57.6kbps, and that's the speed for which you'll usually see ranges quoted, but you can apparently get double or more of that range by dropping them down to 14.4 or 9.6kbps OTA rate. My (potentially incorrect) understanding is that just like phone modems of yesteryear these radios are using tones to transfer the data, so the slower bitrate allows them more time to resolve the signal for each bit that's coming in.
Yes that's true, I guess what I meant is that LoRa takes this to an extreme. For example the 12 bytes in 2 seconds mentioned in the docs is 48 bits per second. Apparently the distance record is 702km for receiving a packet: www.thethingsnetwork.org/article/ground-breaking-world-record-lorawan-packet-received-at-702-km-436-miles-distance
Oh, wow. Yeah that's a little extreme :-)
kynar wire might be useful to replace those bigger board interconnecting wires.
Useful video
Hey. :) Now the is something I would like to know more about. Thx.
Just at the time i needed it. Thank you.
I'd like to point out one thing, I dont understand how the 2.4 GHz and the 5.8 GHz band cause interference with the 433 Mhz band.
as far as i know, different frequencies do not interfere with each other. Please correct me if i am wrong.
Other frequencies don't interfere as much, but their influence is not completely zero, especially when they are much more powerful and in close proximity.
What spreadfactor are you using? If you up it you might get further.
The antennas sold for specific frequencies on AliExpress, Banggood, ebay etc tend to not be centered on the correct frequency and that will have a huge impact on range. I'd be interested to know if your range improved with a more properly tuned antenna.
Also, your antenna polarization was odd for this test, one antenna horizontal, the other vertical...
Hi, Really enjoy your videos. Seems that you have not used LoRa since this video 2 years ago. I think the poor range you experienced is due to the combination of i) slow data rate and ii) moving transmitter (.i.e. on-board your drone). Given that you will generally have line-of-sight to your drone you might get better results with a much smaller spreading factor. This will make the packet transmission time much shorter, which should reduce the effect of the relative motion (which reduces the variance in transmission media characteristics).
Slow data rate should give better range, at least that's how it works with the nRF24 modules and the Voyager spacecraft. voyager.jpl.nasa.gov/mission/science/
Since radio waves travel at the speed of light, I doubt that a plane moving at 15m/s will have any effect on reception quality. Again, look at Voyager which is moving at 17 kilometers per second, or 38,000 mph.
As some other people have suggested, the poor results here might be explained by using crap antennas.
@@iforce2d Thanks for taking the time to reply. I agree that there are a lot of crappy antennas out there, so the ones you used are likely to have been the main problem. I also agree that 15m/s will not create much of a Doppler effect on the signal. Its just that in terms of range, a LoRa modem should be able to do better than an nrf24 module (at the expense of data rate). You show in other videos that you can get great range out of the nrf24 (the weather balloon series was amazing). I was just hoping that I could encourage you to give LoRa another try ...
Your antenna placement should be horizontal both of them... thats why you can't go any further... I suggest you to make diy dipole 1/4 lamda... its easy to make and good in performance... Btw try QCZEK LRS
You mean 1/2 lamda for a dipole!
I just discovered this video. There is not much discussion about your google map API javascript implementation. I quite like that part. I was wondering if instead of manually feeding data on web page in the text box at top it could be automated to take live data and shown on map live ?
Thanks.
If you can get a web browser to read data coming in the serial port somehow, sure.
Sf is spread factor. The higher it is the slower the transmission, but also you can transmit over the longest range. Default Sf is 7, but who knows what they set it to on the init of the lib you're using. Check page 27 on the datasheet: www.semtech.com/uploads/documents/DS_SX1276-7-8-9_W_APP_V5.pdf
They talk about cyclic error coding (Cr) on the same page. BTW, anyone who is at all serious about LoRa, should glance through the LoRa section on that PDF.
Maybe also the problem with your signal is the quality of the antenna's. There is a Swiss guy on the internet who explains a lot on this topic together with esp and arduino's his name is Andres Spiess.
Nice TH-cam movie.
Thanks!
Very interesting song at beginning
Lor lor lor loraaa... 🤣😂
LoRA on 25mw can fet you over 10km with just a dipole and 30km on 1W with the same antenna. Also there is enough bandwith on LoRA to replace current LRS systems.. I'm wondering if the crossfire issnt a LoRA based rc link..
Johan Jonker Surprise surprise, Crossfire is indeed LoRa based :-) So is Frsky R9.
Hi, Could put a link to the video which shows what happens if the antenna is not connected ? Does it break the module ?
Thanks for your videos !
I don't know which video you mean. But it would cause damage to the radio module itself, sometimes quickly, sometimes gradually. I think the symptom would be worse and worse range, until it just stops working completely. But it doesn't really matter does it? The moral of the story is, always connect the antenna :)
Hi, great video. Is it possible somehow receive from 2 or more senders on one receiver? Thanks
At this point I have said pretty much everything I know on this subject in the video :)
I have heard about networks and gateways, addresses, and servers serving multiple clients. I briefly looked at the reliable datagram examples for this library which seem to do something like that, maybe you could see how they work.
Very interesting :)
tbs with 150hz update. QLrs (Diy ) only 15hz update. So idk how to your system ? latency ?
Lora lora lora the explora!
When you are displaying the GPS data collected from /dev/ttyUSB0, if I'm not mistaken that longitude and latitude are for AREA 51. Is this where you are or a joke?
Chris usually "shifts" his location data.
we'll find out soon ;)
It's where he is. They won't let him outside. He's underground in Nevada where it's green.
th-cam.com/video/tUf3H8GvQJU/w-d-xo.html - read the line just above the table you are pointing at, the line that starts with Caution.
Also, there can be problems with the other antenna being so close (even if not powered) on the laptop; but I forget the distance calcs for frequency clearance distances.
20:16 One problem with the setup. the antenna's polarities are not appropriately matched.
Half-dipoles don't have polarity
Is the arduino just because the modules your using don't have a built in UART interface? Am I right in thinking that lora can be used to connect mavlink and if modules with built in UART interfaces are used , its just a case of configuring them and connecting them to the UART of the flight controller and the other on the PC using a USB to serial module?
I have 500mw 433mhz 3dr modules but fancy trying lora, especially the 1w versions :)
For a ground station antenna for my 3dr unit and also the lora if I get them, I'm going to make a ground plane antenna, I already use a home made one for 446mhz on my two way radio at home and they work very well and are easy and very cheap to make if you have a 2m/70cm swr meter, I'm interested to see the difference between the normal mode helical, sander whip, 7dbi Center loaded and the home made ground plane antennas for range :)
Please, what's the best and smallest GPS module with compass ?
You could probably find a smaller one, but this is the smallest I've used: www.banggood.com/Ublox-NEO-M8N-Flight-Controller-GPS-with-Protective-Shell-for-PIX-PX4-Pixhawk-p-1005394.html
Do you have the link to the repository or source of info?
??? There are many links in the description... did I miss something?
Hey man! Been following you for a long time, but for the past 18 months or so I've been away, and I'm dreaming up LoRa devices and functionalities I want to impliment(?) into systems I can sell. I believe I've found a market that likely will be hungry for a good product with this technology. It's very exiting, yeah! I'm nearing completion of a visualized project of mine: a solar-cell powered LoRa-node with 18650 cells for power, and mounted very high up with a superb antenna array. I believe with 10 nodes you can uplink sensors from products you sell to the customers of where you operate this network. Are they farmers? Is it in the city? Suburbs? Dockyard? Industrial Site? War-zone?
There is a market here that is yet to be exploited. I was wondering your thoughts on that?
Can I use LORA module with Arduino for making long range RC plane?
If yes plz send me it's how to make details...with schematics...
Maybe you missed the links in the description, that's all I know. Pin connections and code were discussed and shown in the video. I did not have much success with this, it seems like a bad choice for RC control, unless I could figure out how to improve it much more.
Is it just me or is there a once-a-second tick on the right sound channel? Might just be me losing my mind though...
Quite likely, yes. The house is surrounded by electric fences.
Those are fun! Peed on one as a kid and I can well imagine the shock making its way through the internet, seeking me out again.
Good day sir., can you teach me how to make a drone like you., with lora connection., i well wait your reply sir
th-cam.com/play/PLzidsatoEzejIpdla6_ggPcDCPJ9u4WHj.html
The antenna on the plane is horizontal, the one on the ground is vertical, no wonder the range is not very good :)
see discussion with Alpha Adhito
that is -30db, just because they are not in same plane
wow.. just looked "for discussion with Alpha Adhito" - all that I found was newbs not knowing basics of EM propagation... showing vertical and horizontal spread bubbles, like you need to match them or something. no, that is not how it works (do you even know what e-plane is??). Maybe read the wiki on antenna first???
cross polarization on your antennas that is a 26db loss
see discussion with Alpha Adhito
I bet you'll get x2 the range with the correct orientation also.. the antennas you used suck.. they are close to useless anyways
Arruma sket lora controle que funcione?
try to keep both antennas in the same plain it should be worth about 3 db
Setmodemconfig seems to take a bool as input...
Not sure where you got that idea from, it takes an integer, which is an index into the MODEM_CONFIG_TABLE
www.airspayce.com/mikem/arduino/RadioHead/classRH__RF95.html#af6f6131a36c2a0f84a5883a6ec7acfec
github.com/adafruit/RadioHead/blob/master/RH_RF95.cpp#L14
github.com/adafruit/RadioHead/blob/master/RH_RF95.cpp#L397
How did you map the data on the map like that?
It's using the Google maps Javascript API. Go to the 'loradataviewer' link in the description and view page source.
Can you share the javascript visualization tool
? Just right click on the page and 'view source'
la la la la LooRa, oooo. ugh ugh......very very funny. didnt expect that.
What is the rssi at that distance?
You mean a percentage of how many of the sent packets were actually received? There is no official measurement, so just estimate from how much of the yellow line is missing. You can see the little circles showing the spacing of how frequently a packet is expected.
oh wait.... there is an RSSI value shown when I mouse-over each point, so now I don't get what you're asking.
@@iforce2d I guess I was wondering the rssi levels as you moved away from antenna and what the lowest rssi was the furthered out e.g. -120dB ?
Nice intro lul
Это лучше чип Semiconductor ax8052f143 с архитектурой 8051 .. есть возможность использовать SDK самого чипа Semiconductor ax8052f143 с библиотеками XNB. Это позволяет отказаться от внешнего управляющего микроконтроллера и снизить энергопотребление устройства .......
Takes 2 seconds to send and you send every 1 second...wat?
My friend "Man i would realy like to buy a rc plane"
Me: " You cant have a rc plane if you are not bad ass hacker! - Sended him this video :D
Lora😂😂😂😂😂😂😂😂😂😂😂
You should look at Andreas Speiss's TH-cam stuff. This link is his world record attempt th-cam.com/video/adhWIo-7gr4/w-d-xo.html/ I tjhink he has >200kM for a link. He also has some great stuff on antennas and how crappy some are. Plus how to tune them!