SIM7000-LTE-Shield VS gnss-sdr

I am making a ESP32-based alarm and would like to add the capability to send SMS messages. A SIM7000A shield allows me to do but requires a sim card, and I would like to use a prepaid one (without contract, need to give credit card info, etc). Does anyone recommend one? I am located in the US.

I want to lead off with a big shout-out to Botletics and their (his?) SIM7000 LTE CAT-M1 shield. From the beginning I knew I was going to need wireless connectivity and that WiFi was not going to reach. I considered Blues Wireless, but ultimately went with Botletics + hologram.io and I'm extremely glad I did. I plugged it in, I lightly modified the example code (it was pretty close to what I needed already, I basically just took out the GPS reading and replaced it with an averaged HC-SR04 ultrasonic sensor reading) and it just worked.

Link for modified Adafruit fona library to support sim7600 - https://github.com/botletics/SIM7000-LTE-Shield

Per this link: https://github.com/botletics/SIM7000-LTE-Shield/issues/15

You realise you can write software yourself to interpret the signals from GPS satellites? Here's an open-source implementation.

Something I always enjoy pointing out is that GPS signals can be decoded by anybody, the source code is available here. Needless to say, there are references and calculations based on satellites all over it.

If you're interested in running some code, there's [1] which is fairly active, but as I recall is Linux only. There is also [2] which is a Matlab (or Octave) GNSS receiver implementation; quite well documented and informative. It's meant to be a companion to the author's book [3], which itself I found quite concise and approachable.

[1] https://github.com/gnss-sdr/gnss-sdr

They like to pretend it is using towers or balloons or something else, none of them have ever coherently answered it with a viable way this could result in the GPS we can use from the device in our pocket. It also casually expands the circle of people involved in this conspiracy by thousands, to include all developers at Apple and other phone manufacturers that write/maintain the GPS components of their OS as well as contributors to open source projects like GNSS-SDR, an open-source software-defined GNSS receiver.

People also have to write the software to compute your location from these broadcasts, this means basically every company that has produced GPS receivers would have to be in on it. But there's an open source one, surprisingly nobody has raised an issue as to why it contains all this weird code that doesn't make sense if it's not coming from a satellite.

GNSS-SDR