Sending SMS

[ManiController]

I'm completely new to this, and not sure where to start. I was hoping someone could help. What I want to do is be able to press a button and then the device sends a text message which will be static (always the same) to a static phone number. Would it be easier to somehow trigger a phone to do this, or should the device itself be sending the SMS? Ideally, I want the device to be as small as possible. Thanks!

 

[Harald Kapp]

Both methods are possible.
The cellphone has the advantage that it is an all in one solution including battery etc. that needs only a trigger, e.g. by using the USB port. If you have a spare cellphone lying around, the cost is near zero.
A dedicated GSM module, is much smaller but needs additional hardware like power supply, a housing etc. Modules are easily available, e.g. this one.

Note that 3G networks are being outphased in many parts of the world to be replaced by 5G networks. So to ensure your SMS gadget doesn't become obsolete quickly check the long term availability of radio networks in your area. Use a 4G or 5G module to be on the safe side - at least for a few years