Cannot get IMEI

[erm3nda]

Well.

I've hardcoded ttyUSB0 as modem device, tries to get IMEI but doesn't work.

Is trying code "AT+CGSN\r\n" but returns ERROR.
I tried to send manually the AT command "ATI\r\n" and returns IMEI along other info.

Manufacturer: huawei
Model: E1612
Revision: 11.806.02.03.18
IMEI: 352201030850216
+GCAP: +CGSM,+DS,+ES
                                                                                
OK   

So, once i've edited that it told me that dongle was previously unlocked. I used networkmanager to create new dialup with just name and APN and worked :D

Actual obtainImei() looks like

def obtainImei(port):
    print "\nTrying to obtain IMEI."
    print "The modem will be given 5 seconds to respond."
    ser = serial.Serial(port = port,
            timeout = 0)
    ser.flushInput()
    #ser.write('AT+CGSN\r\n')
    ser.write('ATI\r\n')
    time.sleep(5)
    response = ser.read(4096)
    ser.close()
    imei = re.findall('\d{15}', response)[0]
    if imei:
        print "Found probable IMEI: " + imei
        return imei
    else:
        print "IMEI not found"
        return ''