G’day all, I have 2 of these modules and neither works as expected. I am testing with the sketches on DFRobots website.
The first does not respond at all and the 2nd shows backward ? characters in the Arduino serial monitor. I think this is a character for decimal 255 which is not what I would expect in response to AT commands.
I’ve read that these module can be quite current hungry and at the moment I have access only to USB power. I’m going to collect a 3A psu tomorrow so will update this after that.
If you’ve had any experience with these I’d love to read how you got on.
Problem resolved. The GSM module does indeed chew through the juice. A 3A psu has fixed the problem.
Neat, glad to hear you got it working, Mike!
Well, the initial problem was simply the baud rate for the modem. You may find as I did that it defaults to 115200, not 9600. When you set the serial monitor to 115200 you will get a lot of rubbish (corrupted) characters, so I suggest you set it to run at 9600.
I still have a problem though. It will NOT send an SMS or make a phone call. This is extraordinarily frustrating. I’d love to hear from anybody with similar issues.
Hi Mike60090, I have the same problem with an A9G module. I have an Optus prepaid SIM installed which it is happy with (AT+cpin? => +CPIN:READY) but it won’t register on a network (AT+CREG? =>
Did you end up solving your problem? Sounds the same as mine.
Very sorry - this one has slipped passed our check gate! Our system auto imported this product from DFRobot’s listing. This is a 2G device and there’s no 2G networks in Australia anymore. The frequencies used for GSM have been reallocated for 4G standards.
The A9G will still of course work as a GPS as per Leigh’s review, but not as an IoT modem. The A9 is more or less useless in Australia.
We’ll send an email out to all affected customers ASAP!