User's Manual
57
www.lairdtech.com
Laird Technologies
BTM510/511
Bluetooth
®
Multimedia Module
6.2.1 Initiate ACL Connection from AG (HSP)
AT+HSGD<bd_addr
hex
>
Initiate ACL connection from local headset-gateway instance to remote device with <bd_addr
hex
>.
The remote device must support the headset role (HS) of the headset prole (HSP).
Response: <cr,lf>CONNECT 123456789012,1108,><cr,lf>
Or: <cr,lf>NO CARRIER<cr,lf>
Or: <cr,lf>ERROR 59<cr,lf>
Or: <cr,lf>ERROR 63<cr,lf>
After an ACL connection has been established, the module remains in AT command mode.
S Register 531 is ignored for HSP connections.
If S-Register 345=1, the audio gateway will alert the headset immediately by sending
“RING” or by performing the in-band ringing procedure (depending on S Register 346)
and wait for the response “AT+CKPD=200”.
If S-Register 345=0, an incoming call must be signalized to the HS manually by issuing
“AT+HSGC”. This will either send the “RING” message to the HS or perform the in-band
ringing procedure and wait for “AT+CKPD=200” to be received from the HS.
In the case the headset does not respond, it is the host’s responsibility to terminate the
connection by “AT+HSGH”.
6.2.2 Alert HS by Sending “RING” Message or In-Band Ringing
AT+HSGC
When in “ACL connected” state, the command “AT+HSGC” alerts the HS either by sending
“RING” (if S346=0) or by in-band ringing (if S346=1). In the latter the AG is assumed to
create an in-band ringtone which is audible on the HS through the SCO connection. The
in-band ringtone is not created by BTM5xx itself. It is required to be created by the external
circuit and to be connected to the BTM5xx analogue audio input.
In-band ringing is indicated by “ATI64” returning 6. Alerting using the “RING” message is
indicated by “ATI64” returning 5.
In both cases the response “AT+CKDP=200” (“Button pressed”) is expected from the HS.
6.2.3 Cancel an Ongoing Alert Process
AT+HSGCH
When the HSG is alerting the HS (ATI64 = 5 / 6 ) this state can be cancelled by “AT+HSGCH”.
If in-band ringing was active (ATI64 = 6) , the audio connection will be released.
6.2.4 Release Audio from HSG Side/Transfer Audio from HS to HSG
AT+HSGR
When in “audio connected” state, the AG can transfer the audio connection from the
headset to itself with “AT+HSGR”. This results in the release of the audio connection
whereas the ACL connection is retained. In “ACL connected” state, the headset (HS) is
able to transfer the audio connection back to the HS by sending “AT+CKPD=200”.
6.2.5 Initiate Audio from HSG Side/Transfer Audio from HSG to HS
AT+HSGA
When in “ACL connected” state, the AG can transfer the audio connection from itself to
the headset by “AT+HSGA”. This results in the establishment of a SCO based audio connection.
6.2.6 Connection Release from AG
AT+HSGH
Release existing connection to a HS. If the HS is alerted, alerting will be cancelled. If an
audio connection exists it will be released rst. ACL will be released in either case.
Response:
On audio disconnection (optional): <cr,lf>HSG”AU0”<cr,lf>
On SLC disconnection: <cr,lf>NO CARRIER 1112<cr,lf>
AT COMMAND SET
REFERENCE