It seems that sending "\0" from a terminal (minicom) has no effect - neither does sending \0 (null character) from our firmware. Does this actually work for anyone?
below an example output in a terminal:
SDK 1.0.1 / AT version 0.23
===================================================
AT+RST
OK
ets Jan 8 2013,rst cause:4, boot mode:(3,3)
wdt reset
load 0x40100000, len 1320, room 16
tail 8
chksum 0xb8
load 0x3ffe8000, len 776, room 0
tail 8
chksum 0xd9
load 0x3ffe8308, len 412, room 0
tail 12
chksum 0xb9
csum 0xb9
2nd boot version : 1.3(b3)
SPI Speed : 40MHz
SPI Mode : QIO
SPI Flash Size : 8Mbit
jump t run user1
sl�K
Ai-Thinker Technology Co. Ltd.
ready
AT+GMR
AT version:0.23.0.0(Apr 24 2015 21:11:01)
SDK version:1.0.1
Ai-Thinker Technology Co. Ltd.
Apr 27 2015 13:55:14
OK
AT+CWMODE=2
OK
AT+CIPMUX=1
OK
AT+CWSAP="xxx","xxxxxxxx",5,3
OK
AT+CIPSERVER=1,4444
OK
0,CONNECT
AT+CIPSENDEX=0,100
OK
> ddd123456\0