Recently I have bought GSM modem, I connected it to power, inserted SIM card and it worked well (the yellow led flashing short on / long off) which mean it registered on the network.
Now I still cant communicate with Arduino UNO so I can send SMS.
Can someone help telling me the wiring (pins in GSM and where to connect to Aruino) because there are no label on the pins of the GSM. Also, I will appreciated to tell if any voltage leveling in between because I saw pins with 2.65v in the specs.
Many thanks in advance