It does work! I have called for help in a non-life threatening situation with no cell service by using APRS to SMSGTE while doing some off-roading. Even better, you don't even have to have a digipeater nearby. About once every 1.5 hours you can get a chance to send the packet via the ISS during a pass. SMS via space. :-)

Holy shit game changer. Finally time to dust off that ham license. Any tips on how to setup this ? Ideally I want a cheap handheld system I can send apfrs messages.

Yeah you can use a cheap Baofeng radio (can get as low as $15-20), an “APRS cable” for it (about $20 on Amazon or make your own) which takes mic/ptt and audio out and feeds it to a 3.5” TRRS plug (think iOS / android headphones with mic plug), and an APRS app on your phone.

Radio -> cable -> cellphone audio jack -> APRS app

If you have an iOS device probably using a lightning / usb-c to 3.5” TRRS jack too.

"Radio -> cable -> cellphone audio jack -> APRS app"

While this works, it is just the start. Soon you realize that you want to actually use your phone AND APRS at the same time and that your audio and mic are busy. I did this for about a day before seeking out something better.

Radio -> cable -> Mobilinkd Bluetooth TNC paired to your phone -> APRS app

Now you can take calls, play music in the car and drive down the road with a radio paired and use APRS. This isn't a bad setup, the big pro us the multitasking and using the APRS app on your phone to write messages.

The other way I've done this is a radio that has the TNC and APRS built in. A handheld like the Kenwood TH-D74 can send and receive messages without any additional hardware, but you have to write the messages on a lame keypad like in the dumb phone days. I like this for backpacking as there are fewer pieces to worry about.

It is fun stuff, and can be a life saver. Check out https://hamstudy.org/ the easiest level (Tech.) is enough to get you access to all of this.

Yep totally right. Worth noting that you can use an older phone repurposed for connecting to a cheap baofeng for just APRS purposes. Radios with APRS are great but quite expensive.

Also 100% recommend anyone interested getting their Amateur Radio Technician license. TBH you can pass the test with an afternoon of study, and the advanced licenses are really only needed for additional HF spectrum privileges.

Wow, do you have a parts list on that cheap radio and APRS cable?

I’m using a Baofeng UV-5R (radio) and the APRS-K1 cable. I’ve linked Amazon pages but you can get them for slightly cheaper off eBay or AliExpress.

Radio: https://www.amazon.com/Baofeng-UV-5R-136-174-400-480Mhz-1800... Cable: https://www.amazon.com/BTECH-APRS-K1-Interface-APRSDroid-Com...

It supports an ACK, but unless you have a two-way i-gate nearby you should probably consider it to be a one-way protocol. All of the ones near me just go RF -> internet so there's no way to get a response back to RF unless you're running your own.

Still useful for sending out quick status updates like "I'm doing fine but running late" but not good for full blown communication.

Exactly this. My wife knows not to panic if she can get my messages, but I don't reply to her. If any hams live in an area w/o a two-way i-gate, consider putting one up. It isn't that hard and provides a nice service.