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Walkie-Textie Wireless Communicator

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Re: Walkie-Textie Wireless Communicator

#71

Post by aspenmayer »

pavel_lishin wrote: post #56

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?

Here’s a recent post I found on open source software for that. I remember a recent post about folks using base stations that were popular with the Helium network to run their own stuff, but I can’t find it at the moment.

https://news.ycombinator.com/item?id=44936241

Re: Walkie-Textie Wireless Communicator

#72

Post by loph »

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.

Re: Walkie-Textie Wireless Communicator

#73

Post by addaon »

IshKebab wrote: post #67
addaon wrote: post #52

Earlier quoted context omitted.

They're cheap, robust, readily available, super easy to develop for, have a well-chosen set of peripherals that can reduce BOM even further (e.g. the CCL)… what's not to like?

They have the same price and availability as Cortex M0 chips, are more difficult to develop for (8-bit AVR ouch), and seem to have a similar number of peripherals as any microcontroller. The RP2350 is the same price and several orders of magnitude more capable for example. Really though, how many of these is he making? 3? Cost isn't a factor.

> are more difficult to develop for (8-bit AVR ouch)

I think this just comes down to philosophy. ARM gives you a way richer tool-chain… and you need it. The complexity to do anything skyrockets. You have a compiler in the loop so achieving deterministic performance is much more complicated... not to mention caches. The tooling for doing statistical analysis is infinitely better; but just sitting down with a pencil and doing static analysis will always be both simpler and more accurate. For cases where you're writing thousands of lines, I too will generally prefer ARM -- but if you're just writing a couple hundred instructions, assembly is just less to think about.

Similarly philosophical is "more capable" -- an RP can handle many more use cases, I agree, but if both handle a given use case, with the same quality, then neither is more capable /for that use case/. And the one that achieves that use case at quality with the simpler implementation is, in my philosophy, preferable.

Also, while there are equivalents to the CCL in other processor families, it's by no means universal; and it's not at all rare that the CCL saves one or two external chips.

Re: Walkie-Textie Wireless Communicator

#74

Post by f1shy »

pavel_lishin wrote: post #56

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?

Yes. There is a way to setup a private cell using SDR. There was a talk about that in Chaos Computer Club some years ago. I do not remember how they did with the simcards, if they were custom, or normal out of service ones. Caution: because the spectrum band is licensed, it will be automatically illegal pretty much everywhere!

Here a quick search: https://www.reddit.com/r/sdr/comments/1bn1n5f/how_to_run_ope...

Re: Walkie-Textie Wireless Communicator

#75

Post by f1shy »

lxgr wrote: post #33

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.

Actually some have. At least I know that in Peru, operators were forced to offer such a thing in case of earthquake. I do now have details though, maybe was not simple as I was told.

Re: Walkie-Textie Wireless Communicator

#76

Post by magnat »

junon wrote: post #45
magnat wrote: post #34

> 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.

What's the data transmission rate with the balloon, put of curiosity?

Hard limit is 3.5kbps with 148dB link budget (Medium Fast preset in Meshtastic [1]). In practice - a packet worth of hundred bytes every half a second or so.

[1] https://meshtastic.org/docs/overview/radio-settings/

Re: Walkie-Textie Wireless Communicator

#77

Post by tejtm »

sejje wrote: post #7
etrautmann wrote: post #6

Earlier quoted context omitted.

Can you elaborate on the restrictions? Is it just that the Baofeng allows you to transmit on some frequencies that aren’t legal or at power levels that aren’t allowed or is it not allowed in the US at all?

You need a ham license to do most anything with a Baofeng legally.

No licence is required to listen to any frequency.

Re: Walkie-Textie Wireless Communicator

#78

Post by mikestew »

seidleroni wrote: post #63
joshmarinacci wrote: post #60

Earlier quoted context omitted.

Not really. This stuff is heavily NDA and patent encumbered. You’d be better off setting up a local wifi network and using an IP based audio call system.

I'm not sure if this applies to all carriers but with many carriers if you are on wifi you can send/receive text messages and sometimes even make calls. Certainly you could use WhatsApp or similar in that case.

...with many carriers if you are on wifi you can send/receive text messages...

How would you propose that those messages get routed if there is no connection to either the internet nor a cell provider?

Re: Walkie-Textie Wireless Communicator

#79

Post by opan »

jvm___ wrote: post #53

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 w…

Chaining together a few WiFi routers and running a local IRC server with ergo could work well (so get everyone on the same WLAN even if no Internet). There is also Briar chat on mobile. Maybe Mumble for voice could work. I'd look for routers on Craigslist or eBay that are under $20 each and have OpenWrt support. Have had good luck with the Netgear R6220 in the past, but there could be other good options as well.

Re: Walkie-Textie Wireless Communicator

#80

Post by jeroenhd »

jonbiggums22 wrote: post #70
pavel_lishin wrote: post #56

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?

Isn't this what Wifi Calling is for? https://en.wikipedia.org/wiki/Wi-Fi_calling

VoWiFi requires an internet connection. It dials back to your carrier.

Nothing preventing you from configuring a local SIP server or doing IP-to-IP calls, though. I think every platorm imaginable has some kind of free SIP client.

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