User's Manual

Enhanced Class 1 Bluetooth v2.1 Module
User’s Guide
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CONN-GUIDE-BT740_v0.2
5.3.56 Unsolicited/Async Responses
The ‘AT’ Protocol is a command/response type of protocol. This means that the Laird device normally
only responds to AT commands and in addition only responds to one AT command at a time.
Under special circumstances, unsolicited responses send to the host. They are described
in the following subsections. Each unsolicited response is prefixed and postfixed by a cr,lf
two character sequence.
Command:
No Command. This is a status message.
Response:
RING
Description:
This string sends to the host every second repeatedly when a remote device
initiates a serial port connection. The fully qualified string is in the form RING
012345678901, where 012345678901 is a 12 digit hexadecimal number which
corresponds to the remote device’s Bluetooth address.
The host responds with the ATA command to accept the connection or reject it
using the ATH command.
If S Register 0 is set to a non-zero value then the incoming SPP connection
automatically accepts after the number of RINGS specified in S Register 0 sends
to the host.
Only incoming SPP connections invoke a RING response. Connections on other
profiles automatically accepts.
Command:
No Command. This is a status message.
Response:
PIN ? <bd_addr>
Description:
This response sends to the host during a legacy pairing negotiation (pre BT
version 2.1 compliant devices).
The fully qualified string is PIN? 012345678901, where 012345678901is the
Bluetooth address of the peer device. In response, the host must supply a pin
code using the AT+BTK command.
Command:
No Command. This is a status message.
Response:
PASSKEY ? N <bd_addr>[,passcode]
Description:
This response sends to the host during a simple secure pairing (SSP) negotiation
and when the module is configured appropriately via S Register 9006.
Where N is 1 for the host to display the passkey supplied, 2 for the host to
respond with either the command AT+BTKY or AT+BTKN and 3 for the host to
respond with AT+BTK=”nnnnnn”.
The fully qualified string is :
 PASSKEY? 1 012345678901,123456 where 012345678901 is the Bluetooth
address of the peer device and 123456 is the passcode to display to the user.
 PASSKEY? 2 012345678901,123456 where 012345678901 is the Bluetooth
address of the peer device and 123456 is the passcode to display to the user.
 PASSKEY? 3 012345678901 where 012345678901 is the Bluetooth address of the
peer device and the user echoes the passcode displayed on the peer device, or
agree with the other user to enter the same random 6 digit passcode at both ends.
Command:
No Command. This is a status message.
Response:
PAIR N <bd_addr>
Description:
This response sends to the host on completion (success or otherwise) of a pairing
process. If pairing succeeds then ‘n’ = 0; if a timeout occurs then ‘n’=1; and for all
other unsuccessful outcomes the value is 2.