AT\r --> 'OK' or 'ERROR'
AT+CREG=1\r --> 'OK' or 'ERROR'
AT+CSNS=4\r --> OK or ERROR
AT+CSTT="APN","USER","PASSWORD"\r --> 'OK' or 'ERROR'
AT+CIICR\r -->'OK' or 'ERROR'
AT+CIFSR\r -->'OK' or 'ERROR' and 'ADRES ip'
AT+CIPSTART="TCP","59.17.235.87","15136"\r -->'OK' and 'CONNECT OK' or 'ERROR' and 'CONNECT FAIL'
AT+CIPSEND\r hellow world 0x1A --> 'OK' and 'SEND OK' or 'ERROR' and 'SEND FAIL' (0x1A-->ctrl+Z)
AT+CIPCLOSE\r--> 'CLOSE OK' or 'ERROR'
AT+CIPSHUT\r--> 'SHUT OK' or 'ERROR'