I connected an A6 GSM module to the serial port of my laptop and I get the startup messages (including current date and time so there is a connection to the mobile network). Then I want to send a simple AT command but I don’t get an answer from the module. I couldn't figure out what is wrong so I suspected the module itself. Perhaps a broken RX port .... ? So I ordered another one, just like the one on Raymond Tunnings' site (https://raymondtunning.wordpress.com/20 ... -and-data/). I thought that way I have the same module and I can follow the instructions on his site. Unfortunately this second module behaves exactly the same. There is readable output when the module boots and connects to the mobile network so I'm sure the baud rate is correct.
How can I do some additional troubleshooting to figure out what is wrong? Any ideas somebody?