Remote Switching

Projects General Guidance
1

This is one of those projects that starts off sounding so simple but just gets more and more difficult the deeper you investigate.

The task is to develop a cellular gadget that will allow my customers to switch their alarm system on and off remotely. In the past this was done with simple little GSM gadgets that cost about $5 on eBay. They would send a text message saying either 'ON' or 'OFF' and that was that - very simple. However, with GSM/2G/3G being replaced by 4G, LTE, Cat M1/NB-IoT it seems that I can't use the older style modules because they won't work much longer if at all.

I assumed that buying an Arduino device like this https://shop.sodaq.com/sodaq-sara-sff-r412m.html would work, except that it seems that SMS is not possible everywhere with such devices/carriers. Does anyone know if this is correct?

If so, is there an alternative solution that I could develop which would work globally with SMS or similar? I really don't want to have to ask my customers to download some special app or turn the device into a web server, etc. The simpler the solution the better.

2

4G, LTE

In most cases the devices are backwards compatible. Have you already seen a phone that isn't able to send SMS (part of the GSM standard)? So please define why the current hardware doesn't work anymore in your case.

I assumed that buying an Arduino device like this https://shop.sodaq.com/sodaq-sara-sff-r412m.html would work, except that it seems that SMS is not possible everywhere with such devices/carriers. Does anyone know if this is correct?

A huge overkill in my opinion. My guess is that it gets a lot of work to get that running because the module is so new that probably nobody else did use that before with the Arduino platform. If you just want to use SMS service you don't need 99% of the module and you pay the 100%.