User guide

2. AT Command Set
2.1 Assumptions
The CSR (Cambridge Silicon Radio) BC04 chipset in EZURiO devices is memory resource limited.
Therefore it is NOT proposed that there be full implementation of the AT protocol as seen in
modems. The claim made for this device is that it will have a protocol similar to an AT modem. In
fact, the protocol is similar enough that existing source code written for modems can be used with
very little modification with an EZURiO device.
Therefore the following assumptions are made:-
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 EZURiO 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.
5 All new Bluetooth specific commands are identified by the string +BTx, where x is
generally a mnemonic of the intended functionality.
2.2 Commands
This section describes all available AT commands. Many commands require mandatory parameters
and some take optional parameters. These parameters are either integer values, strings, Bluetooth
addresses or device classes. The following convention is used when describing the various 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’ a
‘a’ to ‘f’.
2.2.1 ^^^ {Enter Local Command Mode}
When in data and connected mode, the host can force the device into a command and
connected mode so that AT Commands can be issued to the device. The character in this
escape sequence is specified in the S2 register, so can be changed. In addition, the escape
sequence guard time is specified by S Register 12. By default the guard time is set to 100
milliseconds. Please refer to Section 5: Dropping Connections for more related information.
In modems this escape sequence is usually “+++”. “^^^” is specified to avoid confusion
when the module is providing access to a modem.
Response: <cr,lf>OK<cr,lf>
2.2.2 !!! {Enter Remote Command Mode}
When in data and connected mode, the host can force the remote device into a command
and connected mode so that AT Commands can be issued to the device remotely. The
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