User guide

2.2.20 AT&F+ {Clear Non-volatile Memory}
This command erases all user parameters in non-volatile memory except S Registers 520
to 525. This means that the trusted device database is cleared, and so are parameters
related to the following commands:- AT+BTR, AT+BTN, AT+BTS.
Response: <cr,lf>OK<cr,lf>
Or
Response: <cr,lf>ERROR nn<cr,lf>
2.2.21 AT&W {Write S Registers to Non-volatile Memory}
Writes current S Register values to non-volatile memory so that they are retained over a
power cycle.
Response: <cr,lf>OK<cr,lf>
Or
Response: <cr,lf>ERROR nn<cr,lf>
2.2.22 AT+BTAn {Control Audio Channel}
Once a Bluetooth connection is active, and assuming the peer device is an EZURIO
device, this command is used to start/stop a SCO channel which will connect the PCM
interfaces of the two peer devices. This means that if a codec is attached to the PCM pins,
then 2-way audio can be established.
+BTA0 Switch off the channel.
+BTA1 Switch on the channel.
On receipt of the command, the following response immediately follows.
Response: <cr,lf>OK<cr,lf>
The lower layers then go through the process of setting up the SCO channel, and as soon
as a SCO link is established, the following response is asynchronously sent to the host.
Response: <cr,lf>AUDIO ON<cr,lf>
Or if the SCO failed to be established.
Response: <cr,lf>AUDIO FAIL<cr,lf>
On the peer device, the host will asynchronously get ….
Response: <cr,lf>AUDIO ON<cr,lf>
2.2.23 AT+BTC<devclass> {Set Device Class Code}
This command is used to set the device class code which will be sent in subsequent inquiry
responses. It can be read back using the AT+BTC? Command, as described below.
<devclass> is a 6 digit hexadecimal number derived as per section “1.2 The Class of
Device/Service Field” of the Bluetooth specification “Bluetooth Assigned Numbers”.
The 24 bits are made of 4 fields briefly described as follows (bit 0 corresponds to the least
significant bit):-
Bits 0-1: Format Type. This field currently only has a value of 00 (i.e. format
type 1).
Bits 2-7: These 6 bits define the Minor Device Class and the value is interpreted
differently based on the Major Device class stored in the next 5 bits.
Bits 8-12: These 5 bits define the Major Device Class as per Table 1.3 in
“Bluetooth Assigned Numbers”.
Bits 13-23: This is an 11 bit field used as a mask to define the Major Service
Class, as per Table 1.2 in “Bluetooth Assigned Number”.
DSH_50003_v1v3 AT Command Reference 18 of 33