Experiment with GPRS
This article documents attempts to connect a Raspberry Pi to an MQTT server through a GPRS Modem.
We have selected initially the Waveshare GPRS Hat... https://www.robotshop.com/en/gsm-gprsgnssbluetooth-hat-raspberry-pi.html
Potential problem - this card requires pressing a button to power up. This could be a big problem as we don't want to have to press any buttons to get it working after connecting power.
This is a low cost modem (around £25) that should be capable of functions required.
It is intended to combine this with a low cost SIM data card designed for MQTT purposes, from Thingstream... https://thingstream.io/products/thingstream-iot-sim/
First successful text messaging
- https://www.youtube.com/watch?v=CNFl8amKHPw&list=PLXm_y6rrNVJcWnuuyelAG1HQx9w_Yepdr&index=3 WORKED !
AT OK AT+COPS? +COPS: 0,0,"T-Mobile" OK AT+CBC +CBC: 0,78,4027 OK AT+CMGF=1 OK AT+CMGS="07557342430" > hello > +CMGS: 212 OK
Ctrl + A then Ctrl + D quits screen.
AT+CSTT="everywhere","eesecure","secure" OK AT+CIICR OK AT+CIFSR ip_address AT+CIPSTART="TCP","heatweb.co.uk",80 OK
This is how to create an internet connection.