Long-Distance Text Communication With LoRa

Affordable and reliable cell phones have revolutionized the way we communicate over the last two decades or so, and this change was only accelerated by the adoption of the smartphone. This is all well and good if you’re living in a place with cellular infrastructure, but if you’re in more remote areas you’ll have to be a little more inventive. This text-based communications device, for example, lets you send text messages without all of that cumbersome infrastructure.

While [Arthur] didn’t create this project specifically for off-grid use, it’s an interesting project nonetheless. The devices use a physical QWERTY keyboard and a small screen, reminiscent of BlackBerry devices from the late 2000s (partially because they are actually using BlackBerry keyboards). One of the other goals for this project was low power consumption, and between polling the keyboard, the memory LCDs, and receiving and transmitting messages using LoRa, [Arthur] was able to get the current draw down to 12 mA.

Between the relatively common nRF52840 and SX1262 chips, plus the fact that [Arthur] made the schematics available, this makes for an excellent off-grid device for anyone who likes to drive off into the wilderness or lives far enough outside of town that cell phone reception is a concern.

Looking for something a little easier to put together before your upcoming camping trip? This similarly styled LoRa communicator from [MSG] uses off-the-shelf modules to greatly reduce the part count. Another option for off-grid communications is to use existing smartphones paired with a LoRa network like we saw in this project.

49 thoughts on “Long-Distance Text Communication With LoRa

    1. The J-Link EDU mini is $20 (hobby, educational, non-profit usage), I would not consider this as expensive. If you are doing things for a business or as a company, then I think anyway you buy the equipment you need.

  1. One drop onto the antenna and it may be dead. I don’t quite understand the love for PCB mounted SMA connectors beyond cheap RF breakout boards when one can fit a u.fl connector and a pigtail adapter, which would then be attached to the enclosure, or installed in an elastomeric grommet.

    1. Makes sense to me. I also have trouble understanding all the fuzz about LORA.
      It’s an interesting modulation scheme, sure.
      But it’s also a vendor lock-in, a dead end.
      Decoding LORA can be done through software with an SDR, albeit it might be a gray zone legally or so I heard.
      By contrast, AM/FM/SSB can be decoded by various technologies – there’s no such monopoly of a single company.
      It truly makes me sad that people don’t use open hardware instead. Unlike LM555, LM386 or 741 ICs, the LORA chips are made by a single company only. Reminds me of the proprietary, patented voice codec ICs used for D-Star and the professional radio.
      Isn’t it ethically questionable to support such a company by buying their chips and give it more power thus? Shouldn’t we boycott them? I mean, if there were ‘compatible’ chips from China, the situation might be different, not sure. 🤷‍♂️

      1. Not really. It’s far more ethically questionable to buy “compatible” (read: stolen IP, so the hardworking devs we designs it don’t get paid) items made by people working in conditions that would be illegal in the US/EU, from a country which is trying to put 2m of its population into “re-education” camps.

        1. There’s only so many ways you can make money out of tech. The competition tried to make the hardware open but the network closed, whereas LoRa makes the hardware closed but the network open. LoRa won the competition.

          In the end, once the patents expire in 15-20 years, you will have your open hardware. In the mean while, pick what’s best for your use case.

        2. And, the problem with “nobody owns this tech, anyone can make it” open hardware is that nobody is developing it seriously. What’s the use, if all your effort is simply copied by everyone else instantly and your investment is lost?

          So, the result will be that everyone who does develop the tech will try to “differentiate” and either change it subtly or add something extra and non-standard to capture the audience from the others, or they try to beat the others to the punch by rushing and releasing too early. That leads to a balkanized system that is complicated, fragmented, often poorly documented as it’s incomplete and always under change, and almost doesn’t work. When someone from the outside (i.e. project managers and system designers) see the result, they see a scene that resembles a bunch of carpenters fist-fighting inside a timber frame that’s never going to be finished into a house. You can wait for the next two decades and it’s still going to be the same.

          Also see: Linux distributions.

          1. Also, there’s already country-wide LoRaWAN, SigFox, NB-IoT and LTE Cat-M networks I can buy access from. Where’s the DASH7 network operator?

            I can’t use it if I can’t choose it, no matter how open source they are.

        3. I never heard of DASH7; probably it should be promoted more. Also, where are DASH7 modules? People would surely use them if they were available and promoted around.

      2. You want to boycott a company because it invented something and is making that thing? I don’t love capitalism, but even I acknowledge that enabling people to leverage their inventions is a positive thing overall.
        Your AM/FM/SSB idea has merit but it’d be higher power, and without being pre-approved would require radio licensing for everyone using it.

        1. You miss my point, I think.

          It’s about building a complete infrastructure upon a proprietary system.

          That’s as if someone encourages a group or society to use a messaging/videochat system that only works on a single product of a single company.

          Or a single chat program that exists for a single OS only.

          AM/FM/SSB -which were just examples-, can be used legally by different groups with different technologies. They’re not the property of a single person or company.

          That’s what I meant. Likewise, the classic Packet-Radio, AX.25 and its AFSK/FSK was explicitly open for everyone.

          Toying with LORA around for fun is fine, sure, don’t get me wrong.
          But currently, there’s almost an obsession going on; using LORA for everything.
          That’s something to think about.

          What if LORA becomes a standard in a specific field and its ic maker, Semtech (?), goes out of business? What happens with the ecosystem when no other company can provide new chips?

          If anyone of you does have at least a little bit of responsibility, please keep quite for a moment and think about such theoretical consequences. Infrastructure is a very sensitive mattee.

      3. > Makes sense to me. I also have trouble understanding all the fuzz about LORA.

        If you find a way to get the same throughput and range with AM/FM/SSB you’ll might get rich.

      4. Also, in most jurisdictions, if you want to use encryption (and not just encoding) at all you will need to have a licence for the frequency(ies) you use. Buying such hardware chips for wireless comms allows you to skip the very expensive step of certifying your equipment if you want to do this legally.

      5. “a gray zone legally or so I heard.”

        There are patents on lora decoding, that’s why it’s important to urgently wake up on the third attempt to impose software patents in Europe, without any appeal possible at the CJEU:

        https://ffii.org/ffii-oppose-the-third-attempt-to-impose-software-patents-in-europe-via-the-upc/

        There are few doubts that giving the last word over patent law to specialized patent judges will end up in a disaster. Like it happened in the US, till the Supreme Court intervened to break the pro-patent doctrines of those specialized patent courts.

        The Legal Service of the Council announced the second treaty of the UPC to enter into force, while the UK was a requirement:

        http://patentblog.kluweriplaw.com/2022/05/19/upc-a-reply-to-those-who-with-the-help-of-a-crystal-ball-have-questioned-the-arguments-as-to-why-the-ppa-is-not-legally-in-force/

        1. Patents better than copyrighting. At least one runs out before everyone you know dies of old age.

          MURS frequencies need to get the unlicensed treatment so we can have another good long range band to play on with stuff like this.

          With licensed ham frequencies they all see to prefer bureaucracy over new projects or concepts.

  2. I applaud the effor but I hope there could be more optimisation possible. 12ma draw on a 1500mah battery sounds like about 5 days life. However the Nokia 105 has a 800mah battery and gets 25 days of standby that’s just over 1mah when not in use. Maybe some kind of sleep/wake pattern could eek the battery out even longer, sleep for 5s wake for 0.5s. Would mean you would need to transmit for 5s to make sure your message gets through. No expert but worth a look.

  3. This is a great project. My first thought was towards environmental disaster. We had a major flood here in Germany not too long with ago failure of mobile communication.
    But if I see it right LORA is not encrypted and also in the project, I have nothing seen in this direction on the quick. Am I missing something or is it OK for all of these projects if everyone can read along?

    1. Yes, the flood.. The old analogue radios from the 1970s saved the day back then. Firefighters and others had kept them in a safe place, gratefully.
      They still worked without a digital, central base station (which were located downwards at a secret location each). Those old radios even could reach it others directly, if needed. Their old FM repeaters, by contrast, were wisely located on the mountains and hills and safe during the flood. The digital communication was a complete fail, all in all.

      That reminds me of something I heard on radio a while ago: It’s a shame that there’s no rule/recommendation that encourages rescue workers to carry citizen radios like PMR, CB or Freenet, too. Because, these little short range radios would allow them not only get in touch with victims who can purchase them/already have them (hikers, kids etc), but also provide a common platform that works between all groups. A simple recommendation would allow to firefighters, red cross, police and rescue workers to talk on channel XY, if really needed. These devices would also make them independent from professional radio and silly bureaucracy. Citizen radios are open to all people, after all.

  4. Reminds me of a toy I had back when I was a kit. It had a monochrome LCD display, a built in keyboard, and a folding antenna. It would send text messages to others of its kind via radio signals. Can’t remember the name and my quick searching hasn’t yielded any results.

    1. In general are these LoRa messengers compatible with each other? I have a WiPhone with a LoRa daughterboard, but only the one. Would be neat to build some devices like this and chat between them.

      1. They almost certainly aren’t compatible, but if this type of device gets popular the format would likely standardize, at least in the open source units.

        It probably wouldn’t be too hard to move the message handling code to any of the usual dev boards and then do things like send and receive messages to/from remote sensors. We should really pull our LoRa code out into a simplified Arduino demo so people can easily do that.

        Porting message formats between other open source messengers could also be done if you are comfortable with embedded code.

        1. We definitely need some kind of open standard for interoperability. I was thinking the wiphone would work great with a “base station”. From there we could pass the messages into another system like email, chat, SMS, or possibly just repeat the message to increase the distance. Very nice looking device.

    1. With both endpoints at ground level, it will depend completely on what is between them and whether you get any lucky reflections. In open field range could easily be 5 km, but in urban environment just some hundreds of meters.

      Many LoRa range estimates assume that one endpoint of communication is a base station up high, but that is not off-grid.

    2. @Kevin Peters Said: “What would be the range of one of these? I don’t see it written (or I missed it).”

      You didn’t miss anything. It takes digging to get straight-forward facts on these Internet of Things (IoT) wireless networks (there are lots of them, all with unique plus overlapping specifications). Here’s what I know about LoRa:

      Directly between two LoRa devices the range is essentially line of sight and it depends on your ModCod (Modulation & Coding) settings. One extreme example: “LoRaWAN distance world record broken, twice. 766 km (476 miles) using 25mW transmission power.”[1] A more realistic example would be 10km or less per low-rate link.[2] But LoRa can be run in back-to-back and/or mesh configuration to extend range & coverage.[3]

      However, if you are connected to a LoRaWAN network run under the LoRa Alliance [4], coverage is essentially global. For example there is The Things Network which uses LoRaWAN.[5] You can run your own LoRaWAN network provided you have a LoRaWAN gateway which uses proprietary hardware and can be kind-of expensive (several hundred USD all-in for a small gateway). Most people just use an existing network or just use LoRa modules directly connected together (no need for a LoRaWAN gateway).

      One thing to remember: LoRa uses license-free sub-gigahertz radio frequency bands EU868 (863–870/873 MHz) in Europe; AU915/AS923-1 (915–928 MHz) in South America; US915 (902–928 MHz) in North America; IN865 (865–867 MHz) in India; and AS923 (915–928 MHz) in Asia; and 2.4 GHz worldwide.[6] However while the sub-gigahertz bands are well covered globally, they are regional only, but regions are still interconnected via the Internet via the likes of The Things Network. The 2.4 GHz license free band is Global, but not well supported yet.[7] Without global 2.4 GHz LoRan coverage, applications like asset/package tracking are troublesome.

      * References:

      1. LoRaWAN® distance world record broken, twice. 766 km (476 miles) using 25mW transmission power

      https://www.thethingsnetwork.org/article/lorawan-distance-world-record

      2. Lora Range Test

      https://reibot.org/2017/04/23/lora-range-test/

      3. LoRa Mesh Networking with Simple Arduino-Based Modules

      https://nootropicdesign.com/projectlab/2018/10/20/lora-mesh-networking/

      4. LoRa Alliance

      https://en.wikipedia.org/wiki/LoRa#LoRa_Alliance

      5. The Things Network

      https://www.thethingsnetwork.org/

      6. LoRa operating bands

      https://en.wikipedia.org/wiki/LoRa#Features

      7. Semtech launches LoRa in 2.4 GHz, LoRa Alliance not yet on board

      https://rethinkresearch.biz/articles/semtech-launches-lora-in-2-4-ghz-lora-alliance-not-yet-on-board/

  5. Has anyone got the lora llcc68 ebyte 220 E220-900T22 modules working? I tried all the code i could find but never got a transmit to happen.

  6. Hi there,
    I am looking into improved communication options for cattle ranchers out of cell service in Montana. Some of them use InReach devices, but I am looking into other possibilities. Would these devices be able to text with cell phones in cell coverage or just other devices like them? If the landscape is fairly dynamic (forest, mountains, valleys, gulches) will that prevent good communication? Is it necessary to have something like a gateway or antenna on the landscape for the devices to connect to? How far apart can people be to communicate between devices? I would love to learn more and see if this is something we could look into as an option for our situation. Thanks a lot.

  7. Reading through all these different LoRa projects for if the communication grid goes down really feels like a rehash of the xkcd comment about standards. Each one is basically identical besides maybe one or two minor features at most, and none are interoperable. If things actually went to shit wed be f***ed because everyone is speaking a different language over LoRa. Feels like we need something like Activitypub where the different implementations can at least understand the basics of each other’s packets and enable interoperability.

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