Long Range Transmission



  • Has anyone tried to use any variants of the radios to cover a very long range ~800 meters? I ran across this:

    http://flutterwireless.com/

    I wonder if this could be used as a bridge between sensors to cover a longer range. Or am I reinventing the wheel here?

    I have a gate that is 800m away that I would like to open/close via mysensors.



  • @Ironbar said:

    Has anyone tried to use any variants of the radios to cover a very long range ~800 meters? I ran across this:

    http://flutterwireless.com/

    I wonder if this could be used as a bridge between sensors to cover a longer range. Or am I reinventing the wheel here?

    I have a gate that is 800m away that I would like to open/close via mysensors.

    Yes. I use the nrf24l01+ pa/lna modules for that. But they tend to be a little problematic and need extra care to work on long range. (Such as a clean and stable power source and additional shielding because most of them aren't shielded)
    I never tried the more expensive shielded nrf24l01+ pa/lna modules but it is on my list.

    Looking at the flutter they are using something in the 915/886MHz range to communicate over long range (xbee?) also the boards seem to be partially shielded, which is a good think.

    There are pro and contra on using a lower freq. to communicate:
    Pro: More stable on higher range with less energy
    Contra: Less Speed (Means: should be good to transmit sensor data etc., but if you want to transmit video or pictures you are probably out of luck)



  • I have not had much luck with the nrf24l01+ pa/lna modules. They only seem to transmit about 300m. I'm going to setup an outdoor test this summer to see if I can get them to transmit further.

    Are you getting 1000m out of them?

    I've never tried the shielded modules. I didn't even know they existed. I guess I will throw them in the test as well. I will still be highly surprised if I can get 800 meters out either one of them.

    Thanks for the info!



  • I have wondered about putting a solar powered repeater in the middle...



  • @Ironbar said:

    I have not had much luck with the nrf24l01+ pa/lna modules. They only seem to transmit about 300m. I'm going to setup an outdoor test this summer to see if I can get them to transmit further.

    Are you getting 1000m out of them?

    I've never tried the shielded modules. I didn't even know they existed. I guess I will throw them in the test as well. I will still be highly surprised if I can get 800 meters out either one of them.

    Thanks for the info!

    I got 1000m on clear line of sight out of them, yes. Its a matter of shielding, clean power supply and correct antenna alignment.

    @Lawrence-Helm said:

    I have wondered about putting a solar powered repeater in the middle...

    Is doable, but you will probably need to use a rather big solar cell and battery. I'm currently building some nrf24l01+ nodes with 20 watt solar cells. I think i can give some results in about 1 month.


  • Admin

    you could also do it with rfm69 instead of NRF24, it's capable of longer ranges, as it is using lower radio frequencies.



  • @tbowmo is totally right at this one, also it consumes less power.
    Though... for my use case i need the higher datarate the nrf24 supports.


  • Mod

    If need the higher data rate, a repeater might not solve your problem since it cuts practical data rate at least in half (probably more due to contention and increased round trip times)



  • @mfalkvidd said:

    If need the higher data rate, a repeater might not solve your problem since it cuts practical data rate at least in half (probably more due to contention and increased round trip times)

    Well.. still faster then rfm69. πŸ˜„ Actually i never tried whats the highest datarate i can achive on repeater mode. I do not need it yet and will probably try to switch to the esp8266 if i ever need it.


  • Hardware Contributor

    Hi.
    Like others said, for longe range, I bet on rfm69 too. and it's mysensors compliant. I think if we would use radiohead lib, lora rfm95 is very interesting for some outdoor application. But I think using radiohead as it is, is maybe too much memory consuming for what we need but it looks well written...I don't have time to, so pure speculation..but I'm very tempted to test some lora modules in future because I will have some outdoor projects. And I have seen this very nice module recently, for gw or other thing (but not arduino compliant yet). They claim a very impressive range, and it's multi radio...things are going crazy, so good for us πŸ™‚ :
    https://www.kickstarter.com/projects/1795343078/lopy-the-lora-wifi-and-bluetooth-iot-development-p
    Sorry for this little OT...just my 2cents πŸ™‚


  • Hardware Contributor

    @scalz If I find the time I will look into making a atmega1284p based node. I know this works with the MySensors lib (I made my own arduino with this mcu), and I'm also interested in building a node with lora radio's.
    The matter of protocol and radio type is a very stimulating topic in the City of Things community here in Antwerpen. The current gateways in the living lab (our city is an open lab for IoT now) have lora radio's (among others). So it would be nice to be able to use the Radiohead library.
    An atmega1284p has plenty of memory and the picopower version can still go very low power.


  • Hardware Contributor

    @GertSanders : that is very good news πŸ˜‰ I have some 1284p at home too, moteino mega homemade. I have already designed something for this chip +rfm69 too, but pcb are not ordered yet...I don't have lora yet. I thought too about adding the lora footprint, fun! Lowpowerlab has already a lora version πŸ˜‰
    I don't know if you have seen it, 1284p at ali are cheap, I have some and tested one for the moment but works well
    for radiohead lib, yep it would be great, but it requires some stuff on code part, and you are right 1284p could be a good candidate!


  • Admin

    @scalz @GertSanders

    Another option could be atmel SAMD... Dev branch has support for it.

    I'm considering making a node with a D20, which can go up to 256kb of flash.


  • Hardware Contributor

    @tbowmo: yep, I completely agree, I think it would be a very very cool thing. I wanted to make one, but no time to test everything unfortunately..(but I have all the components!), so I am waiting after your work πŸ˜‰ ). So for the moment I have just designed only one thing for 1284p.
    So why not sam L21 as it is picopower? In other hand, for the moment it is a little bit more expensive than aliexpress 1284p. But that is not the same power!! And if bought at Mouser, sure the difference is not big!
    Sure I prefer atsam πŸ˜‰ I let you doing it, you are more skilled on this than me! plus I have so much things in progress, hw/sw, and trying to make a mobile app that make me some headhache! ouch I need some pause!!


  • Hardware Contributor

    @tbowmo I also considered the SAMD, it's just that I received some atmega1284p from atmel (SMD samples), so I thought of doing a board for those first.

    My first design for this mcu was for the 40 pin DIP version. I use this for all sorts of demo's and tests at our codedojo. I plan to update this design, and try my hand at smd.

    0_1455893982285_IMG_7776.jpg

    I received these from atmel, but I realised too late that they would be impractical to handsolder. I would love to use them.

    0_1455894390511_IMG_7781.jpg


  • Admin

    @scalz

    Are saml21e18 available on aliexpress.com? Have searched but can't find any..


  • Hardware Contributor

    @tbowmo No, I got these as samples from Atmel. They were nice enough to send me samples so I can test with them. Could not find any saml21e18 or samw25xxx on Aliexpress.


  • Hardware Contributor

    @tbowmo: no, I have not seen atsam at ali.
    I was saying that

    • 1284p 2.6€ at aliexpress or 7.4€ at digikey for instance.
    • atsaml21e18 6.39€ at digikey.

    atsaml21 make me curious πŸ™‚ I hope they will lower the price.. When I see at lowpowerlab, there is moteino mega 1284p. I imagine that the next 32bit "move" could be atsaml21 if we compare the price..Something like neutrino but with atsaml21for picopower+radio footprint could be very cool! this is the idea I wanted to do but not enough time..and with a good power supply of course πŸ™‚ With atmel uC, we are rather sure that it will be arduino integrated faster. But there are lot of other promising things in future, so I am a little bit lost for the moment!! when you see esp32 or this LoPy...and I think for basic temp node things, 8bit is better πŸ™‚ but for more advanced cool things, 32bit +picopower...

    @GertSanders : very nice board πŸ™‚


  • Admin

    @scalz

    About 8bit vs 32bit, it depends on price. I would take the cheapest one available.. and it seems that it could be the cortex M0+ family (samd2x / L21 etc.)

    if you check mouser prices, 1 pcs. of atmega 328p-au (32pin tqfp) the price is 3.52$ for 1 pcs. While the atmel samd20, also 32pin tqfp, and 32Kb flash (so same amount as in atmega328p) is priced at 2.74$ for 1.

    So in this respect the 32bit processor is winning in price. I have not looked at power consumption between the two, but as we are sleeping most of the time anyway, it might be comparable..


  • Hardware Contributor

    @tbowmo, @GertSanders
    I wanted to add to mytinycaml board few improvements. And as it is something much more for telemetry, why not add LORA πŸ˜‰ Here my plan:

    • keep ulpnode part
    • footprint for nrf24||rfm69||rfm95

    I have found "standalone" libs for uno/328p but like we said, it is too limited. So I'm looking between 1284p and ATSAML. As I'm in ulpnode land, SAML is pico and SAMD some uA (seems the same thing 328vs328p). Hopefully, they are pincompatible (1 pin differs: vcc instead of io). My dilemma for the moment is:

    • I'm trying to keep the same size (50x23) with all on top layer and 805(or 603 max). I want to keep this one handsolderable
    • I need to add JTAG (and there is already a big MYSConnector...). Too bad to need an ICE3, I need to find a cheap one.
    • I know 1284p, and arm0..not yet. but 1284p is bigger footprint. So I should stop to be afraid lol If I go for arm0, will you be ok to check my arm0 "typical application schem part" ??
      Or maybe do you prefer teamwork? Problem...is I am eagle addict..

  • Hardware Contributor

    Personal opinion: go for ATSAM


  • Hardware Contributor

    I'm still not fully out of atmega land, and I have a few atmega1284p lying around (in both DIL and SMD versions), so I need to give them a "home".

    My arduino adventure started with the intention of building a mobile robot. This dream/project is still on the radar, but my foray into sensors has helped regain knowledge I lost, and I'm still learning new stuff, so the more practical home projects now get precedence over my robot pet project.

    Given the cost of a raspberry zero, the idea of a plugin board with the necessary radio's is not so far fetched either. For AC based sensors anyway.


  • Hardware Contributor

    @GertSanders : thx. Like you I have too much mcu in collection and wanted to give a 'home" to my 1284 too πŸ™‚ but I agree with you, and I already know what tbowmo will tell me πŸ˜† So I will give it a try. I know if I have some trouble there is an awesome community πŸ˜‰



  • @Oitzu said:

    @Ironbar said:

    I have not had much luck with the nrf24l01+ pa/lna modules. They only seem to transmit about 300m. I'm going to setup an outdoor test this summer to see if I can get them to transmit further.

    Are you getting 1000m out of them?

    I've never tried the shielded modules. I didn't even know they existed. I guess I will throw them in the test as well. I will still be highly surprised if I can get 800 meters out either one of them.

    Thanks for the info!

    I got 1000m on clear line of sight out of them, yes. Its a matter of shielding, clean power supply and correct antenna alignment.

    Are you shielding the antennas on both ends to get the 1000m? I'm rebuilding my gateway now so I wonder if it would be worth waiting on a shielded antenna. The shielded antennas I bought say 1300m line of sight.

    @Lawrence-Helm said:

    I have wondered about putting a solar powered repeater in the middle...

    Is doable, but you will probably need to use a rather big solar cell and battery. I'm currently building some nrf24l01+ nodes with 20 watt solar cells. I think i can give some results in about 1 month.

    I would be very interested to see this project. My barn is about half way down my driveway at 400m so I may be able to put a repeating node in there. My problem is, I do not have clear line of sight to my mailbox because my property is hilly. I would have to put a antenna on my barn that sticks up in the air 15m and I do not want to do that.



  • @Ironbar said:

    Are you shielding the antennas on both ends to get the 1000m? I'm rebuilding my gateway now so I wonder if it would be worth waiting on a shielded antenna. The shielded antennas I bought say 1300m line of sight.

    No, i'm shielding the modules itself. The cheap PA/LNA modules are not correctly shielded.
    Have a look here to get an idea: http://forum.mysensors.org/topic/1877/2-x-nrf24l01-pa-lna-with-rf24_pa_max/14

    I would be very interested to see this project. My barn is about half way down my driveway at 400m so I may be able to put a repeating node in there. My problem is, I do not have clear line of sight to my mailbox because my property is hilly. I would have to put a antenna on my barn that sticks up in the air 15m and I do not want to do that.

    I will put up some pictures soon. I'm currently debugging 3 build nodes and plan to place them in 1-2 weeks.
    Well yeah you probably need repeaters for that. Signals don't propagate that great through ground. πŸ˜‰



  • I remember sometime back someone was working (or talking about) integrating the RadioHead library into MySensor...
    so we could have any radio, with Mesh, or Repeater as part of My Sensor...

    Is anyone still working on this??

    and yes, using low cost, lower power 32 bit processors, is a good move forward....

    Oh, just a note, new Moteino are now available with lora rfm95 radios

    Thanks





  • hello I made some range test using the LoRa Modules RFM96 (433mhz) , I was able to get data at 5.2miles ( low speed) transmission.
    still trying to understand the radioHead libray.. for my test I use the example rf95_reliable_datagram_client.pde
    see more details of my test here..RFM96 LoRa
    my problem is I am not so advanced when programming arduino in the way to pack data using struct , for example I want to send between nodes the status of 3 or 4 Digital inputs and and at least 2 or 3 internal calculations based on analog inputs.
    Anyone could help me with that?

    typedef struct{ // this is the data that I would receive from master
    bool RDI1; // command for turn on/off an digital ouput
    bool RDI2; // command for turn on/off an digital ouput
    bool RDI3; // command for turn on/off an digital ouput
    bool RDI4; // command for turn on/offf an digital ouput
    int RVar1; // value
    int RVar2; //value
    }
    Recdata;
    Recdata Rdata;


  • Hardware Contributor

    @tbowmo: hi. I will see if i keep this like a proto or if i do a better one but I wanted to share what I'm checking and panelizing today for fun. i will see what I get from this..and now i'm waiting my t962 to hack it, mine yeah!, so cool my birthday sooner lol, so I'm happy that's why I share ahaha you can say it πŸ™‚

    Inspired from nice adafruit design, sparkfun, yours too πŸ˜‰ I made my version, for my proto needs.
    Atsamd20/21E tqfp.
    I rerouted and added : protection+filter for usb, different ldo, eeprom, atsha, mysxconnector, lora or nrf, antenna pad or connector, ws2812b. Programming pads for pogopins on bottom. everything is on top. i'm thinking to put a jumper to use for another purpose usb datalines. it is a lipo charger version so usb connector should stay I guess, at least for power??? i will certainly make small mux changes.
    Size 2.4x5.5cm, 0603, 2layer
    daughter boards : 2.4x4.2cm (max)
    So on a 5x10 (cheap) , I will have two atsam + two daughter boards.
    0_1457300121069_2016-03-06_21-14-17.png
    In the picture :
    With nrf, simple but fun actuator : with a mems+gesture+rgb led
    With LORA, for weather optional sensors : ctn, si7021, bme280, veml6070, opt3001, as3935. it should easily fit in atsam, and because I have them in stock so why not πŸ™‚
    what do you think?



  • @Ironbar I did some test with the nrf24l01 the one that come with the pa + lna amplifier (100mw) and get more than a 1km on LOS.
    you may also try the RFM69HW.. the one that has 20dbm output.


 

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