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www.lairdtech.com
Laird Technologies
BTM510/511
Bluetooth
®
Multimedia Module
CONFIgurINg
THE BTM510/511
AT Command Set
Assumptions
1. All commands are terminated by the carriage return character 0x0D, which is represented by the string
<cr> in descriptions below this cannot be changed.
2. All responses from the device have carriage return and linefeed characters preceding
and appending the response. These dual character sequences have the values 0x0D and 0x0A
respectively and shall be represented by the string <cr,lf>.
3. All Bluetooth addresses are represented by a fixed 12 digit hexadecimal string, case insensitive.
4. All Bluetooth Device Class codes are represented by a fixed 6 digit hexadecimal string, case insensitive.
Commands
The following syntax is employed throughput this document to describe optional or mandatory parameters for
AT commands.
<bd_addr>
A 12 character Bluetooth address consisting of ASCII characters ‘0’ to ‘9’, ‘A’ to ‘F’ and ‘a’ to ‘f’.
<devclass>
A 6 character Bluetooth device class consisting of ASCII characters ‘0’ to ‘9’, ‘A’ to ‘F’ and ‘a’ to ‘f’.
N
A positive integer value.
M
An integer value which could be positive or negative, which can be entered as a decimal value or
in hexadecimal if preceded by the ‘$’ character. E.g. the value 1234 can also be entered as $4D2
<string>
A string delimited by double quotes. E.g. “Hello World”. The “ character MUST be supplied as delimiters.
<uuid>
A 4 character UUID number consisting of ASCII characters ‘0’ to ‘9’, ‘A’ to ‘F’ and ‘a’ to ‘f’.
General AT Commands
1. AT
Used to check the module is available.
Response: <cr,lf>OK<cr,lf>
2. ATA {Answer Call}
Accept an incoming connection, which is indicated by the unsolicited string
<cr,lf>RING 123456789012<cr,lf> every second. 123456789012 is the Bluetooth address of
the connecting device.
Response: <cr,lf>CONNECT 123456789012<cr,lf>
3. ATD<bd_addr>,<uuid> {Make Outgoing Connection}
Make a connection to device with Bluetooth address <bd_addr> and SPP profile <uuid>.
The <uuid> is an optional parameter which specifies the UUID of the profile server to attach to,
and if not supplied then the default UUID from S Register 101 is used. As this is a device
which utilises the RFCOMM layer as described in the Bluetooth specification, it necessarily implies
that only profiles based on RFCOMM can be accessed.
The timeout is specified by S register 505.
Response: <cr,lf>CONNECT 123456789012<cr,lf>
Or <cr,lf>NO CARRIER<cr,lf>
Due to a known issue in the Bluetooth RFCOMM stack, it is not possible to make more than
65525 outgoing connections in a single power up session. Therefore if that number is exceeded,
then the connection attempt will fail with the following response:-
Response: <cr,lf>CALL LIMIT
Or <cr,lf>NO CARRIER<cr,lf>
In that case, issuing an ATZ to reset the device will reset the count to 0 and more connections
are possible.
