I wonder if you could build on Jeff Geerling's work: https://www.jeffgeerling.com/blog/2022/using-4g-lte-wireless...

To me it’s to opposite! I’m looking for a device that does not have a baseband on it. I can always hotspot + vpn if I need access to the outside world, but no direct access to the device. Add some encrypted chat software, and got the perfect communication device.

https://store.planetcom.co.uk/products/gemini-pda-wifi-only was an option but sadly they pivoted to devices with baseband only...

There's https://pyra-handheld.com/ but it's semi-existent not-quite-vaporware for about a decade already (props on the staying power of looking to get this project finished, though!)

Gemini also the disadvantage of horribly out of date software. Encrypted chat software is not a good combination with Android 8.1 missing years of security patches.

Planet Computers are probably going down the drain soonish after the fairly disastrous crowdfunding for the Astro phone. I know a friend who has a Gemini and he wasn't impressed either. However I am massively biased, as I paid for a Astro which I'm still waiting for several years after the kickstarter finished. To be fair, they have had pretty major issues with the ODM, but still we've only just found that out recently.

https://www.indiegogo.com/projects/astro-slide-5g-transforme...

I make a VoIP/WiFi phone that excludes any sort of cellular radio because that's what I want as well:

https://wiphone.io

You know you can do that on Android with termux, right?

https://wiki.termux.com/wiki/Termux-telephony-call

until termux gets banned from android for empowering users too much, anyway

it's already banned from updating in google play

Just use F-Droid or download from GitHub then. The power of Android is that you're not in a walled Google Garden and you are in control and can sideload whatever you want from wherever you want.

that's what i'm doing now, but it's probably only about 3 years away that google disables the api level that termux depends on; then you'll have to install lineageos or something in order to be able to use termux

One project I think about a lot but will probably never do is build a DIY smart phone, writing all the UI and features myself.

There's people on youtube that have done this. They're basically off the shelf parts and a raspi glued together in an awkward brick of wires and electronics.

I'm interested in learning how to get the hardware all working together, but also making wacky UI that deviate from normal smart phones.

Too bad I'm lazy!

Ha I actually had the same thoughts about building an eReader with an eink display and everything. I actually put it together and wrote it with Python for epubs and everything. Then I realized I suck at UI stuff so it’s just sitting at like 65% complete… which is better than my average project actually!

Maybe the uConsole?[0] An internal 4G modem is an option, though I don't know if it can make calls. That said, judging by the forums, the lead time is like 8 months, which is a bit much . . .

[0]https://www.clockworkpi.com/uconsole

the clockwork-pi uconsole is a handheld small linux device with 4g options; don't know if they are shipping yet.

That keyboard looks incredibly hard to type with, no?