Hello, I bought 2 sparkfun pro Rf boards and I have been trying to make them work in point-2-point communication, it is working fine at distances up to 1 meters but as soon as the distance increase i stop receiving the messages. I am using 2 UFL antennas operating at 868 MHz ( https://linxtechnologies.com/wp/wp-cont … -pw-qw.pdf). I tried different frequencies (864 to 868 Mhz) as well as different LoRa parameters (SF, BW, CR) to no avail. I closed the LoRaWAN jumper on the underside of the board for previous tests.
I followed the tutorial to set the 2 boards for the radio communication. When using the lastRSSI function implemented in the RF95 library I receive RSSI of about -85 dB.
I tried to change the antennas with a spare one that I had but it didn’t help me either.
I am welcome to any suggestions that you might have.
Interesting. It sounds like there is either a connection issue with the antennas or possibly the code is not configured correctly. How are you testing the range? Are you using the LoRa WAN Arduino Example example from the [Pro RF Hookup Guide? If so, double check you are defining the configuration to the correct frequency in that example since it defaults to 915MHz. If you are just using the [Point to Point Arduino Examples, try de-soldering the LoRaWAN jumpers on the back, double-check the frequency setting, and retest.
Hello, I am using the point to point example and I did change the frequency. I will try de-soldering the LoRaWAN jumpers and replacing the antennas by wire of appropriate length.
I tried what you mentionned but it didn’t resolve my problem. I tried replacing the antennas by wire of good length(86 mm as indicated in the tutorial) and I obtainned a very small increase of range (something like 0.5 meter).
I tried analysing the RSSI with the function lastRSSI available in the RadioHead library and I obtained RSSI ranging from -75 at ~10 cm to -95 at 1 meter(with the wire antennas).
I took some picture of my setup, one of the board is connected to my laptop while the other one is connected to an external battery(I commented the line testing the Serial connection ).
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I kind of messed up when de-soldering the LoRaWAN jumpers on this one.
Interesting. Everything in your setup looks okay here so we can rule out a connection issue. Just to confirm, you are setting the frequency by either uncommenting or editing [one of these two lines in the Client/Server examples, correct? And you have tried the full band from 863-870MHz?
Hello, yes I am uncommenting the line setting the frequency at 864.1 MHz and commenting the one setting it at 915 MHz. I did try different frequencies between 863-870 (3 or 4) and I tried my setup outdoor already so the interferences are not really likely.
Usually I see a complete loss of packet directly related when my 2 boards get a bit too far from each other.
I’ve read that it is probably caused by faulty hardware, is it possible ?
I agree, nothing in your setup seems to be the cause of the issue so it is safe to conclude that one or both of the Pro RF boards have an RFM95W module that is not working properly. I think what would be the best option here would be to have one replacement Pro RF sent and you can test it with both to see if you can identify which one is malfunctioning. If you get the same results from both boards, then a second replacement would be the next step.
If you purchased the Pro RF’s directly from SparkFun, please fill out the form on [this page and in the “Why do you want an RMA?” box, enter a brief description of the issue and link to this thread and we will follow up with further instructions for the RMA process. If you purchased it from one of our Distributors, you will need to contact them directly. Feel free to refer to this forum thread, if necessary. If you have any issues with that process, please send me a Private Message and we can assist you further.](Return Policy - SparkFun Electronics)
Ok, so I ordered 2 new boards (to be safe) and started testing with one of them aqnd the old ones. At first I managed to obtain a range of up to ~5 meters with the U.FL antennas once and then I had the same problem as previously (very short range). I then tried the 2 new boards together and I still had the same range issues.
I then replaced the U.FL antennas by wire which didn’t solve anything. I will try changing the Frequency into the US frequency to test it out.
Is there anything I should have been careful about when handling the boards (not putting my fingers somewhere in particular, etc…). I always powered the boards through the Micro-USB-B port so I don’t think I could have damaged them with a voltage too high.
Do you have some references about the RSSI I am supposed to get at short range with these boards and wire antennas? It would help me identify the source of my problem.
Well that is just frustrating. My thoughts here are either there is a lot of interference around the 868MHz band where you are testing, the RFM95 is not tuning to the EU 868MHz band effectively or something really weird is happening with that u.Fl antenna causing the antenna line to fail/malfunction (very unlikely). Try testing on 915MHz and a wire antenna and see if that helps anything.
I would need to do some more digging to find some more references for the RSSI you should be getting but as a quick option, take a look through the [datasheet for the RFM95 if you have not already. I will talk to our RF pros at SparkFun on Monday and see if they have any insights into what might be causing the issue here.](https://cdn.sparkfun.com/assets/learn_tutorials/8/0/4/RFM95_96_97_98W.pdf)
Yes I have had the same issues on 4 boards. Bought another set and they wont work more than 5 feet apart and with the large antennas. 2 separate batches of 2 boards and no luck. Anything to look into for these? Both are setup for the point to point configuration.
What frequency are you running the RFM95W (915 or 868MHz)? Are you using antennas purchased from SparkFun or another supplier? If they are from another supplier, can you share the datasheet, please? If they are from SparkFun, can you provide the specific part number?
Ok, with the help of someone who is better at this than me I found out that the power is not properly set in the example.
At the line where it is written :rf95.sexTxPower(14,true).
you have to change it to rf95.setTxPower(13)( or any other value between 0 and 20 according to the doc). The boolean true indiacates that the RFO pins are used and on the RFM95W they aren’t.
I would be interested to know if this tutorial actually worked for someone, as it simply seems to be incorrect.
So with this I obtain about a RSSI of about -25 when the two boards are 30 cm apart.
I did some tests and I obtain a range when there is a line of sight between the 2 boards of about 600 meters with the default parameters(SF7, 125KHz, CR4/5). I tried with other parameters too but I couldn’t use the SF12 no matter which other parameters I set, the boards simply doesn’t seem able to receive messages with SF12.
Awesome work! You could probably just comment that “setTxPower” line out since the RFM95 defaults to a 13dbm transmit power but if you want to customize it, that would probably be the best way to do it. We are going to look into this issue further and we will get our examples in the Hookup Guide updated.
For now, if other users run into this like jocko, try just commenting out that “rf95.setTxPower(14, true);” and see if that fixes the issue. If not, follow the tip rondoudouche laid out.
Let us know if you continue to run into issues with range or have any other questions about the Pro RF and we would be happy to help. Thanks again for digging into this!
Hi there, thank you for the fast reply. I am using the 915Mhz, I copied the code straight from the hookup guide. As for the antennas, I am using the Sparkfun Pycom LoRa and Sigfox Antenna Kit - 915MHz. Part# WRL-14676.
I had same issue on with wire antennas on the first batch of boards. RSSI is showing anywhere from -85 to -100.
TS-Mark:
Hi jocko,
What frequency are you running the RFM95W (915 or 868MHz)? Are you using antennas purchased from SparkFun or another supplier? If they are from another supplier, can you share the datasheet, please? If they are from SparkFun, can you provide the specific part number?
Great, thanks for clarifying what parts and frequency you are using. Have you tried the suggestion laid out above from Rondoudouche or just commenting out the “setTxPower();” function? If you have not, give that a shot as commenting that function out should set it to default (13dbm) and you should be getting much better ranges or you can use the fix Rondoudouche laid out and you can set it to a value between 0 and 20.
I know this is an older posting but thought I would add to it as it relates to my issue.
I am using the ESP32-1-channel-rfm95. I am using the SF antennas 915MHz WRL-14876 antennas of both TX & RX connected to the boards using the Interface cable WRL-00662 to the board U.FL connected, firmly connected and the cable is wrench tight in antenna. I am running the example sender and receiver programs included with LoRaLIB library. As part of the receive program it reports the RSSI and SNR. I have set transmission power to 20 (note the library says max is 17 but the library will accept 20 but not 21 as an input. It errors out at 21) From 17 to 20 there is whats looks to be a slight improvement raising the RSSI about 5 points.
My issue is what appears to be significantly lower RSSI numbers then I feel are acceptable, and that includes the industry also. The radio are going to need to be as long a range as I can get with clear line of sight but a minimum of 5000 meters, basically straight up in the sky.
Here are the current ground testing results I am getting: (this is with power setting of 20)
4 meters : -104 avg RSSI, 10.5 avg SNR
40 meters: -138 avg RSSI, 4.6 avg SNR
At 150 meters the signals are very weak and reception is very spotty with -145 RSI, and negative SNR
I have read a lot on the web and basically they feedback is the antenna is the issue. I noted that the chinese data sheet shows near “perfect” testing results for the 915 band. Well it is a chinese supplier and +40 years dealing with chinese technical data from an R&D engineering position, you need to take their responses with a grain of salt. SF question: have you yourselves ever actual tested this product? If yes can you provide the data results, please. Do you sell any other antennas that you would believe to have better working responses? I am in the act of ordering antennas from LINX Technologies to see their results. (Also in an earlier post you will note I questioned SF about the antenna connection to the module which could certainly be better then the known questionable U.FL or just a cheap piece of wire soldered to the board.)
If it is not the antennas then can anyone offer any other suggestions or feed back? From above in this post I see others are having difficulties with this issue so I bet their may be others. Your thoughts, comments and hopefully your solutions would be helpful.
