Hi there,
After some research I'm looking for solutions with you masters of universe. This is my situation:
I connected one SIM800L module withing following pins from Uno (10, 11, 2[reset to NPN transistor]), external power supply, ground connecteds with arduino, SIM800L and obviously power supply 3Amps, 3.8V).
I'm using this hookup schematics. GSM SIM800L Sheild with Arduino - Tutorials
I just using arduino to send and receive AT commands.
I already tested VIVO and Claro providers (I'm in Brazil).
SIM cards works on conventional phones to make and receive calls and SMS.
No PIN password on neither SIM cards.
Serial communication is working fine.
Without SIM card I get AT+CSQ (23,0) response, in other words good signal from aerial.
I tested ALL AT+CBAN="*" alternatives with AT+CFUN=1. In some cases I got Vivo registration, good signal strength but when I tryed ATD I got no carrier. No SMS messages also.
Depends on CBAND configuration I get AT+CREG: 0,2 or 0,3. I could get 0,1 just once.
Is there a any sequence for starting the module?
Any sequence with AT commands? I'm stucked in this for a week.
A clue will be more than welcome.
kind regards