- AT and AT+ commands can be used to manually collect simple information. This is an ideal choice for "full control" over the communications that are sent and returned from the phone. These can also be used when there is no tool available to communicate with the phone. These commands were tested using a Motorola v551 GSM phone using Bluetooth and USB data cables. It is important to note that not all of these commands are supported by all phones, but the AT+CLAC command (usually) displays all of the available commands the GSM phone can respond to.
- With Motorola phones (and many others) there are NO AT commands that can be used to retrieve multimedia content. For these, OBEX commands must be issued to the phone to return directory contents, ringtones, pictures and video.
- Samsung GSM phones, on the other hand, DO have AT commands that allow access to the multimedia content.
To use these AT commands:
- Connect the phone and determine the number of the COM port that is associated with it.
- Open HyperTerminal, Realterm or any other terminal program that will communicate with a specified COM port.
- With the Motorola phone, type AT+MODE=2. This prepares the phone for an extended AT+ command set. (+Cxxx and +MPxx)
After following these steps, you can continue with any of the commands below.
Lists the phonebooks that the phone contains. (Choose phonebook storage)
Returns: +CPBS: ("ME","SM","MT","ON","DC","MC","RC","EN","AD","QD","SD","FD")
+CPBS="ME" sets the "retrieve mode" to the internal phonebook.
+CPBS="SM" sets the "retrieve mode" to the SIM phonebook.
Describes the phonebook selected above. (Simple) This gives the max number of entries the phone can contain. It also gives the maximum phone number (or email address) length and name length.
NOTE: You can substitute +MPBR for any +CPBR command, but the phone returns a much more specific (and less intelligible) response containing more fields that may act as internal “programming” flags of some sort.
Returns: +CPBR: (1-1000),40,24
AT+CPBR=[beginning index],[ending index]
Returns a list of numbers with the index between the two numbers entered. Also denotes what TYPE of phonebook entry was selected.
Returns: +CPBR: 9,"18005555555",129,"Contact Name" – 129 refers to a phone number.
Returns: +CPBR: 18,"email@example.com",128,"Contact Name" – 128 refers to an email.
Returns the specified index.
Returns: +CPBR: 18,"firstname.lastname@example.org",128,"Contact Name"
Searches the phonebook for the Name or string.
Similar to above, but a more verbose result is displayed.
Returns: +MPBR: 1-1000,40,24,8,0-1,50,(0,2,4,6,9-30,255),(0),(0-1),(1-30),(255),25,(0-1,255),264,(0),0,0,0,0,0,0,0
- 1-1000 denotes the number of entries that can be stored on the selected (+CPBS) phonebook.
- 40 represents the number of characters that the email or phone number can have.
- 24 indicates the number of characters the “friendly” name can have.
- The 8 refers to the different “types” of phonebook entry (i.e. Mobile, Main, Email, Home, Fax, Work … etc).
- The +CPBR command does not list anything after the 24 (as seen above), so there are times when the +MPBR may be useful.
Returns: +MPBR: 18,"email@example.com",128,"Contact Name",6,0,255,0,0,1,255,255,0,"",0,0,"","","","","","","",""
This tells the phone to display the entries as text rather than binary. +CMFG=0 would display the data in binary format.
This displays all of the locations in which the phone can save the SMS messages.
Returns: +CPMS: ("MT","IM","OM","BM","DM"),("OM","DM"),("IM")
Returns the options on which messages you wish to display.
Returns: +CMGL: ("REC UNREAD", "REC READ", "STO UNSENT", "STO SENT", "ALL")
Selects and displays all of the SMS messages on the selected source.
Returns the IMEI of the phone.
Returns: +CGSN: IMEI356252000861622
Returns: +GSN: 299B5900 (Samsung)
Returns the manufacturer’s OS revision.
Returns: +CGMR: "R47_G_08.17.0FR_01"
Returns the manufacturer name (Samsung).
Returns: +GMI: SAMSUNG
Returns the make, model and capabilities of the phones.
Returns: +CGMM: "GSM900","GSM1800","GSM1900","GSM850","MODEL=V551"
Returns: +GMM: SCH-A670 (Samsung)
Returns the subscriber name/number from the SIM.
Returns: +CNUM: Owner Name,15555555555,129
Lists AT commands that the phone supports.
Prepares the phone (Motorola) for OBEX commands.
This returns the phone to simple AT command mode.