User's Manual

33
www.lairdtech.com
Laird Technologies
BTM510/511
Bluetooth
®
Multimedia Module
2.9 SPP – S Registers
S Registers for SPP are summarized in Table 3.10.
Register Default Range Description
S0 0 -1..15 Number of RING indication before automatically
answering an incoming connection. A value of 0
disables autoanswer. If -1, then autoanswer on one
RING and do NOT send RING/CONNECT response
to the host. This emulates a serial cable replacement
situation Setting values >= 0, resets S Register 504 to
0 and <0 forces 504 to 1.
If S0 <> 0 and S100 <> 0 then S0 must be < S100. If
a value is entered which violates this rule, then ERROR
29 is sent in response.
If S504 =1 then this register will return -1, regardless
of the actual value stored in non-volatile memory.
S100 15 0..15 Number of RING indications before an auto
disconnection is initiated. A value of 0 disables
this feature. If S0 <> 0 and S100 <> 0 then S0
must be < S100. If a value is entered which violates
this rule, then ERROR 29 is sent in response.
Table 3.10: S Registers for SPP
 3. A2DP(AdvancedAudioDistributionProle)
The “Advanced Audio Distribution Prole” is used for unidirectional transmission of high quality audio
streams between two Bluetooth devices. A2DP must be enabled by setting S 102 to a value of 128.
Also, an A2DP role must be assigned to a BTM module, either source or sink. After this has been done,
the settings need to be stored by AT&W followed by ATZ.
An incoming A2DP connection request is accepted automatically if a valid link key for the paging device
exists. If no link key is available, Secure Simple Pairing (SSP, BT2.1) or legacy pairing (BT2.0 or earlier) is
carried out, depending on the Bluetooth version of the paging device.
After an A2DP connection has been established, the module remains in AT Command mode. S Register
531 is ignored for A2DP connections.
Version 1.2 of A2DP is supported.
The A2DP service record contains an optional eld which indicates the A2DP supported features of
a device. This feature eld can be set by S312 for a sink and by S313 for a source. Please refer to
Table 3.16 for details.
Table 3.17 gives an overview on supported A2DP features on a BTM device.
Table 3.12 lists supported A2DP codec types.
A2DP Feature Support in SRC (Audio Source) Support in SNK (Audio Sink)
Spec. BTM5xx Spec. BTM5xx
1. Audio Streaming M Yes M Yes
M: mandatory
Table 3.11: A2DP Supported Features on BTM5xx
A2DP Codec Type Support in SRC (Audio Source) Support in SNK (Audio Sink)
Spec. BTM5xx Spec. BTM5xx
1. SBC M Yes M Yes
2. MPEG-1,2 Audio O No O No
3. MPEG-2,4 AAC O No O No
4. ATRAC family O No O No
M: mandatory
O: optional
Table 3.12: A2DP Supported Codec Types on BTM5xx
AT COMMAND SET
REFERENCE