Radiochat Is A Simple LoRa Interface Over WiFi

LoRa is often talked about as a potentially useful solution for emergency communication. The problem is, few of us are running around with LoRa hardware on a day-to-day basis. Student [William Barkoff] designed the Radiochat device as a simple tool that could pair with virtually anything over WiFi, and allow it to send and receive LoRa messages.

Radiochat is based on the Raspberry Pi Pico W, and uses the microcontroller’s wireless hardware to communicate with other devices. It provides a WiFi network that devices like laptops or smartphones can connect to. The Pico serves up a simple web page which accepts text input. Type in a message and hitting enter and the Pico will command a LoRa radio module over SPI to send that message out over the airwaves. It can then be picked up by another Radiochat module which displays the message on its own webpage.

It’s in an early state of development, and the demo video shows there are still some bugs to work out. Ultimately, though, it could be a cheap battery-powered device that lets smartphones and laptops chat over LoRa in remote areas. Indeed, [William’s] trips to New Mexico on model rocketry expeditions were a big inspiration for the project.

20 thoughts on “Radiochat Is A Simple LoRa Interface Over WiFi

  1. For emergencies, a self contained device would be nice…

    Could the electronics be stuffed into an old Nokia 3310?
    Reuse the display and keypad – for a retro T9 interface (to discourage too much spamming).
    Bonus points if you also achieve weeks of battery life

    1. “for emergencies” ?? hahahahaha…. good luck with that !

      Yup, I’m heading out on an expedition to say Mt Everest (to photograph
      myself next to GreenBoots, and tread around on frozen shit)….but instead
      of a *real* HF radio, or SATCOM handset (ie. Iridium 9575), or Garmin
      InReach), i’m going to schelp along a homemade contraption to send
      life critical / mission critical messaging.

      “homemade experimental” + “mission critical” don’t play well together.

      Other than that, interesting – experiment.

    2. I’m not sure it would have much use in an emergency. There are no LoRa basestations with any level of disaster-proofing, most don’t even have battery backup.

      LoRa range is really not that great if the other end is not a high tower. Direct point-to-point without line of sight between two devices on ground level, you can expect 100-500 meters in urban environment.

      It also takes a significant amount of power when the receiver is on. Normally the devices negotiate a schedule with the base station.

      1. Thanks for this pointer – looks like this is already available from the network/protocol/software side.

        I was more concerned about the hardware. Having a controller / small text display / keypad included does not increase the cost very much… But would greatly make this work standalone.
        Think of rugged Nokia 3310 style handsets, standalone…

        Solving emergencies is certainly not going to happen with a single hand-made device. But in the long term – a low cost decentralized messaging system could be worth analyzing. Comparing different lora and lorawan protocols with a dedicated tetra network would make for a great thesis

    3. “Could the electronics be stuffed into an old Nokia 3310?”

      Egads! Another person who wants to gut antique electronics and stuff them with newer circuits!


  2. Nice student project.
    Please use the ground and power rows on a breadboard and only use red black for power, not for data.
    How is G1 of the Adafruit module connected? Connected to the bottom “+”-rail where it’s shorted to pins G2 to G5?
    Have a look at Meshtastic, Reticulum with Rnode or which offer the same (or better) functionality.

    1. RNode/Reticulum offers remarkably worse functionality. I’ve tried it with supported (heltec v2) and unsupported hardware (self built), and neither works. I also tried just straight Reticulum-over-v6/Reticulum-over-udp. Neither of them work even though Wireshark shows the packets reaching the network and the receiving node. The only thing I found with RNode/Reticulum was a new way to break. As for, that project is now dead. The only good one left is Meshtastic which still seems to have some issues. I think Meshtastic was the only one of these actually tested in the real world with different hardware. We need some simple alternatives to the currently only maintained LoRa comms tool.

      1. Pretty sure you’ve managed to b0rk something then, caus I have 30+ devices running Reticulum across both LoRa, WiFi, serial ports and Ethernet, distributed over many square miles, and with how well it’s working, it’s honestly almost magic.

        I just logged into a remote sensor station that is 18 miles away over lora using the “rnsh” utility (like SSH over Reticulum). Works perfectly even over a 900 bits per second link. It’s pretty neat.

        1. Oh, and I forgot to say, that since you can write Reticulum programs in Python, it’s almost too easy to write any kind of small utility or program you need when you have a network in place. Coming from network programming with TCP/IP, Reticulum is much, much easier.

    2. Another alternative would be to learn for a ham radio exam and revive Packet Radio/APRS. Recent developments like FX.25 can increase reliability, too.
      In Europe, CB radio can be used for digital modes, too.

  3. Interesting, but I wonder if they ever heard about the Reticulum networking protocol, which actually has been used successfully in emergencies.

    Even over slow LoRa links, it allows everything from messaging (both local and globally routable), realtime chats and offline delivery, to file transfers, remote shell logins, and even has node-hosting program for serving lightweight “web-like” pages.

    Also works over packet radio, CB, WiFi, Ethernet, the Internet.. Basically anything, and networks are completely interconnectable via any medium.

  4. Pour info, le terme LORa ne s’applique pas en WIFI ou sur internet. Le LORa (long range) utilise des emetteurs 315MHz ou 434MHz de faible puissance sans aucune connexion wifi pour transmettre des trames radio… Et en lora, on utilise jamais de bout de fil comme antenne, on utilise des antennes optimisées pour maximiser la portee…

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