Hello. I’m trying to make a project with my Arduino and a SIM800L module (The red one with the spring like antenna). I activated my SIM card and tried it in my smartphone (and it’s working). The problem is that i cannot call the SIM card once i put him in the SIM800l. I’m supplying the module with a 4.5V/3A power supply but the red LED blinks 3 times and then stops for 30 seconds and blinks again 3 times. Another problem that i have is that i already tried a few different sketchs but i can't send any AT commands to the SIM800l module. Any ideas of what can be the problem?
Thank you!
If it is the module I think it is (like mine) 4.5v is too high.
From the data sheet
If the voltage > 4.4V, the following URC will be reported: OVER-VOLTAGE POWER DOWN and the module will be automatically powered off.
Try 4.2v.