I have a M590e GSM module (assembled from a kit)
it is this kit in this link
I have sucessfully interfaced he module a PC and it does recognise AT commands sent through the serial port. When the module starts up (with sim inserted) it does NOT say PBREADY. After waiting a few minutes after startup.
I type in the command (with the sim inserted of course)
I get the response
which I think means it is searching for a network. When I take the sim card out of its holder and measure the voltage pins that supply power to the sim card (the VCC,GND pins in the sim card holder) I get a reading of 0.01v with a multimeter-is this normal?-should it be at least 1.8v here?-does the voltage increase in specific circumstances when the sim is inserted? Im not sure, but is my module faulty? I cant figure out what the fault is. I have been unable to connect any sim to a UK network so far-and I have tried three different sim card (all known to be working from testing in a phone).