On Thu, 28 Nov 2019 20:40:15 +0000, alan_m
wrote:

On 28/11/2019 19:46, Lee Nowell wrote:
That sounds interesting so the module is in the bell box itself? Do you have the make / model of the gadget by any chance? Assume there is a "permanent" live feed to the bell box?


It was fitted very many years ago and an early version similar to....
https://www.adventcontrols.co.uk/pro...burglar-alarms

It was a credit card size board that I fitted myself to the alarm box.
The alarm box was fully wired to the alarm panel which supplied power
(the bell box has rechargeable batteries maintained by this power) The
GSM card has "trigger" inputs connected to the signals that will set the
bell/stobe off and/or monitoring the power to the bell box.

https://cdn.shopify.com/s/files/1/11..._Dialler.pdf?5


I'm about to put something similar together using a ESP32 SIM800L:

https://randomnerdtutorials.com/esp3...-messages-sms/

Cheers, T i m