DVK-BTM521 Laird Technologies, DVK-BTM521 Datasheet - Page 93

• Manufacturer Part Number: DVK-BTM521
• Description: BT MM DEV KIT
• Manufacturer: Laird Technologies
• Type: Transceiver, Bluetoothr

Specifications of DVK-BTM521

• Frequency: 2.4GHz
• Interface Type: RS-232
• Processor Series: BTM521
• Silicon Manufacturer: Laird Technologies
• Kit Application Type: Communication & Networking
• Application Sub Type: Bluetooth
• Kit Contents: Development Board & Software Tools
• Features: Supports CSR
• Rohs Compliant: Yes
• For Use With/related Products: BTM521
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: DVK-BTM521

BTM520/521
Bluetooth
AT COMMAND SET
REFERENCE
93 www.lairdtech.com
®
Multimedia Plus Module
Mnemonic
HSP
Headset - AG
Headset - HS
7. UUIDs in service records of HSP
8. Page Scan / Inquiry Scan Interval and Window
This section provides some background information on UUIDs and their usage in service record of
the Headset profile.
In the “Bluetooth Assigned Numbers” document [8] in the table “Service classes”, there are three
UUIDs assigned for the HSP:
In the service record for HSP 1.2 - Headset role ([4], page 21), the following values are assigned:
In the service record for HSP 1.2 – Audio gateway role ([4], page 22), the following values are assigned:
The tables above show that UUID 0x1108 identifies the Headset profile whereas the role is explicitly
identified by the ServiceClass0 UUID (0x1131=HS / 0x1112=HSG).
Although UUID 0x1108 appears in the service records of both Headset unit AND Audio Gateway,
0x1108 is still used as identifier for the Headset role in CONNECT and NO CARRIER messages on
BTM520/521.
In HSP1.0 - headset role, 0x1108 was assigned to both ServiceClass0 and Profile0, i.e. it appeared
twice in the service record of a HS-unit and once in the service record of the audio gateway.
Predecessors of the BTM520/521 (e.g. BISM2) have used 0x1108 as identifier for the Headset role.
This was inherited on BTM520/521 and is the reason why 0x1108 is still used in BTM520/521
“CONNECT” and “NO CARRIER” messages.
The logically correct UUID for the HS-role would be 0x1131.
When using the AT+BTIV<BdAddr>,UUID
supported profile and roles, the user must be aware of the circumstances described here. (E.g. do not
assume the remote device supports the headset role if UUID 0x1108 was found in the service records
but still check for 0x1112)
Page scanning means being connectable. Inquiry scanning means being discoverable. With the
following S registers, the power consumption of the BTM can be influenced. However, lower power
consumption means longer connection establishment time and longer time until a BTM is discovered
by other devices.
The page scan window defines the time for the module to look out for incoming connection requests
(paging). The inquiry scan window defines the time for the module to look out for incoming inquiry
requests (device discovery). If the module is both connectable and discoverable (512=4 or AT+BTP
issued), it will mutually do page scanning and inquiry scanning as shown in Figure 3 28. If connectable
only, the module will perform page scanning only (repeatedly) and if discoverable only, then the
module will perform page scanning only.
Item
ServiceClass0
Profile0
Item
ServiceClass0
Profile0
UUID size
uuid16
uuid16
Table 3.55: Selected items of HSP - audio gateway role service record
Table 3.54: Selected items of HSP - headset role service record
Table 3.53: Bluetooth Assigned Numbers for HSP
UUID
0x1108
0x1112
0x1131
Value
“Headset”
“Headset Profile”
Value
“Headset Audio Gateway”
“Headset Profile”
hex
to query UUIDs of a remote device in order to determine
Profile [Ref #5]
See Headset Profile, Bluetooth SIG
See Headset Profile, Bluetooth SIG
Bluetooth Headset Profile, Bluetooth SIG
UUID
0x1131
0x1108
UUID
0x1112
0x1108
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