Neat! At 24mA the suggested battery will only last 10 hours.
Shouldn't it be possible to use such a LoRa device - at least in listening mode without an active display - for much longer time periods?
For anyone looking for an off-the-shelf solution for wireless texting, I've used the BTECH GMRS-PRO. You can send messages on the device, but it's much easier to connect it to your phone via BLE and text through the app.
However, it uses GMRS bands, not LoRA, so all the FCC restrictions apply.
Lora data rate is still maybe 100x or 1000x higher than I'd want. I'd like something just fast enough for text chat, let's say 10 bps (maybe 3 chars/sec with some data compression), and a fallback slower rate for messaging, like 1 bps or slower (2 minutes for a 50 char messsage). That would give another 20 or 30 db of coding gain for much better range. There could even be a .01bps mode. Finally, put it on HF for worldwide range ;).
This is all deployed by hams down to around 1 cps, by the way (js8call.com).
The Lora radios also have a longer-range 325 bits/slower mode called LR-FHSS which does frequency hopping and has 10-60 dB better sensitivity. Though only the sending part is implemented in the low power chips.
While people did get really fast at typing on those num keypads, there was a lot of RSI injuries among people who did it often. a number key bad might be the best compromise despite that, but don't lose sight of just how bad they were and take effort to avoid the issues.
Reminds me of what the messenger on the Cybiko was trying to be. Too bad LoRa wasn't a thing back then, it would have been more useful if it had a better range.
It uses the slow method where you push the same key until you get the letter you want to show up? Does anybody remember T9? You push the keys for the letters you want and it figures out what you're typing from a dictionary.
It's a real shame phones don't have something like this built in. I mean, we literally have satellite communication in every iPhone – or, depending on how you count, every LTE phone, period!
Technically, it seems like 90% of what's required is already there anyway, but due to commercial and political pressures, we'll probably never see it happen.
> LoRa can reach a range of up to 3 miles (4.8 km) in urban areas, and up to 10 miles (16 km) in rural areas
In mountainous area LoRa on 868MHz band reaches over 100km. Last month we had a stratospheric balloon with a Meshtastic node attached. It established direct (albeit intermittent) connection between Warsaw and Berlin.
I'm backwoods camping next week, and we have 25 people spread out over three sites. I was thinking it would be funny to bring some old rotary dial phones and some sort of way of hooking them up, and then just have that as the intercom between sites for when dinner is ready or whatever.
It's next week, so unlikely to happen and I'm not sure what technology I would need to make it all work. Something like Lora plus a way to make the phones work.
Regular walkie talkies + VOX + headset re-assembled into the phone handset ? Make the phone hook a switch to cut the mic (err, like it originally did, I guess). It's not elegant but it could be a quick evening's work.
Actually I have/had a lot of these. They can only be used with triple a batteries and don't last long. The usb c is only for development (and still lacks power so you still need batteries). The typing as maybe expected gets tiring. I tried using different compression ideas to save characters.
There is no resend or reliability in the message sending. If it fails you must retype it. I can't remember exactly if it even indicates it fails? I remember testing with two devices, one in a faraday to test bad conditions.
In the end they got salvaged for parts from my kids for other projects.
The goal was to have a simple backup/emergency communication device and get to learn about LoRa. Not sure which other devices I will try but definitely know more what to look for now.
A question for folks who know things I don't: if I wanted my phones to work in an area without cell signal, for just me and my family, is it possible to build a "personal" cell tower that our phones would just connect to and work, and allow us to text each other? Or is there a whole layer of auth required for our various phones to actually be able to use a fake network?
There are micro-towers for cell phone testing you can buy and cell phones think it's a real tower. Law enforcement uses one of them to track criminals IIRC.
I've tried and tried to use LoRA devices w/ meshtastic for various things, and can't get them to communicate reliably. Even with two devices sitting next to each other. Not even working reliably enough to be used as a toy. What am I doing wrong?
Thanks. I'll stick to a walkie-talkie. FRS radios are cheap, easily obtainable, and will work as far or farther than this 915 MHz stuff.
If you get into deep shit, some amateur FM handy-talkies are IMHO more likely to be able to get you help. Or perhaps T-Mobile's T-Satellite service if you are headed somewhere really remote.
Unpopular opinion: Meshtastic is a solution in search of a problem.
Very nice. I'd like to see one like this that uses frequencies that can pass through 200m of rock. Obviously the radio frequency will need to be much, much lower (https://en.wikipedia.org/wiki/Through-the-earth_communicatio...). Why, you ask? Cave rescue situations.
I was trying to do something similar with esp32+lora development boards.
And I got like 3km range in my city so it was great !
But then I wanted to make it a ""usable"" thing and started getting stuck on designing a protocol that allows multiple senders at the "same time".
I thought of doing a time slice system since this whole project was inspired by a telecommunications class I had, but the issue would be that people you would need to know in advance the number of slices and your assigned one and also the devices would have to be synchronized, and I really wanted to make it dynamic, do anyone can just turn on their thing and it does a sort of handshake until everything works.
If anyone has pointers It'd be very appreciated, I found out about meshtastic.org while doing this project too.
In the end this was my first embedded experience, and my first embedded with Rust, so at least I got something "working" but I would love to make something as "usable" as this post.
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[ 2.8 ms ] story [ 64.0 ms ] threadAmazing work with an ATtiny814, only 8KB. Love it.
However, it uses GMRS bands, not LoRA, so all the FCC restrictions apply.
This is all deployed by hams down to around 1 cps, by the way (js8call.com).
https://www.cnx-software.com/2025/08/12/lilygo-t-lora-pager-...
https://en.wikipedia.org/wiki/Cybiko
Technically, it seems like 90% of what's required is already there anyway, but due to commercial and political pressures, we'll probably never see it happen.
In mountainous area LoRa on 868MHz band reaches over 100km. Last month we had a stratospheric balloon with a Meshtastic node attached. It established direct (albeit intermittent) connection between Warsaw and Berlin.
Why do people still use these ancient chips?
It's next week, so unlikely to happen and I'm not sure what technology I would need to make it all work. Something like Lora plus a way to make the phones work.
There is no resend or reliability in the message sending. If it fails you must retype it. I can't remember exactly if it even indicates it fails? I remember testing with two devices, one in a faraday to test bad conditions.
In the end they got salvaged for parts from my kids for other projects.
The goal was to have a simple backup/emergency communication device and get to learn about LoRa. Not sure which other devices I will try but definitely know more what to look for now.
You must be mistaking this design for another one. This one was released only a few weeks ago, and specifically offers LiPo batteries:
"The PCB has space for a 2-pin JST socket that will allow you to plug in a standard LiPo battery, such as the ones supplied by Adafruit."
Legally? No. But it's totally possible.
There are micro-towers for cell phone testing you can buy and cell phones think it's a real tower. Law enforcement uses one of them to track criminals IIRC.
But it's very tightly regulated.
https://github.com/joshmarinacci/rust-tdeck-experiments
If you get into deep shit, some amateur FM handy-talkies are IMHO more likely to be able to get you help. Or perhaps T-Mobile's T-Satellite service if you are headed somewhere really remote.
Unpopular opinion: Meshtastic is a solution in search of a problem.
And I got like 3km range in my city so it was great !
But then I wanted to make it a ""usable"" thing and started getting stuck on designing a protocol that allows multiple senders at the "same time".
I thought of doing a time slice system since this whole project was inspired by a telecommunications class I had, but the issue would be that people you would need to know in advance the number of slices and your assigned one and also the devices would have to be synchronized, and I really wanted to make it dynamic, do anyone can just turn on their thing and it does a sort of handshake until everything works.
If anyone has pointers It'd be very appreciated, I found out about meshtastic.org while doing this project too.
In the end this was my first embedded experience, and my first embedded with Rust, so at least I got something "working" but I would love to make something as "usable" as this post.