All commands must be sent ending with \r\n  (10,13)

You can read the device on linux console with a simple:

cat /dev/ttyUSB0

and have another console making the writes to the device, for example:

printf "AT+GMR\r\n" >/dev/ttyUSB0

which will print you the copyright and versions


Important: 
seems some uart come by default as AP mode, not client mode.


Number	Network Mode
1	Network Device (client)
2	Access Point (AP)
3	Both


To get the mode:

printf "AT+CWMODE?\r\n" >/dev/ttyUSB0


If it returns 2, you should set to 1 with:

printf "AT+CWMODE=1\r\n" >/dev/ttyUSB0


Note: if only garbae is read, try setting speed with command:

screen /dev/ttyUSB0 115200

and then kill this screen process (should be two in memory)

Note for Mac OS X users:
device can be found in path /dev/cu.usbserial or something similar
