Several years ago I embarked on an adventure to create a cellular payphone.
- an old payphone.
- Arduino 2560 Mega.
- LTE1690 IC to generated Touchtone.
- LMC6484IN to generate dialtone.
- MT8870 to decode touch tone.
- SIM900 to make cell calls
- 4 relay module.
The Arduino was used to interface between the various modules. Collecting coin values before a call was allowed. Collecting and sending dialed digits to the sim900. Refunding or keeping money if the call was not or was successful, etc.. I'm sure there are easier ways to accomplish a cellular payphone phone But happily the project was a success and has worked well... Unfortunately when 2G was shutdown in the US. The SIM900 no longer works for making calls.
I've seen a lot of chatter regarding the SIM7600A-H. There are references to it being used on the RPI.. Most of the reviews seem to be in reference to data and not so much calls. I'm just wondering if anyone has used the SIM7600 to make cellular calls or if another equivalent to the SIM900 might be available?
TIA
