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DSH_BT024-00200_1v4 © Ezurio Ltd 2006
11
7.3
AT Overview
The AT command set is well known by engineers and was developed to aid the integration of PSTN modems. It
provides simple high level commands for complex functions that can easily be incorporated into programs or used
within programming scripts.
Ezurio has used this familiar concept and extended it to
Bluetooth
to simplify the integration of
Bluetooth
for
product designers. Rather than having to understand the many stages of setting up a
Bluetooth
connection or
function, a single AT command is all that is required.
For example to connect to a
Bluetooth
device with an address 00809844EA13, all that is needed is to send the
string
ATD00809844EA13
to the UART of the Embedded Intelligent
Bluetooth
Module. The module will attempt to make a connection and
return (connect 00809844ea13,1101) or (NO CARRIER), depending on whether the connection was successful.
The scope of the AT command set developed by Ezurio is such that most
Bluetooth
functionality can be covered,
greatly reducing development time.
To provide additional functionality a range of “S” registers has been implemented. These allow program settings
to be stored to control the Embedded Intelligent Serial Module function and also give access to configuring and
reading ports and status registers within the Embedded Intelligent Serial Module.
Full details of the AT command set are provided in the Blu2i AT Command Reference Manual.
7.3.1
AT features at a glance
7.3.1.1
General
•
Configure two modules to automatically connect and transfer data, audio or a combination of
data and audio when both devices are powered. The peer device does not have to be another Intelligent
Serial Module. It is possible to implement auto connect with a
Bluetooth
enabled mobile phone.
•
Automatically re-connect devices when a connection is dropped.
•
Remotely access the AT parser of the remote unit from a master device to perform Over The
Air (OTA) configuration.
•
Configure the module to enter a state on power up and after a period of time change to
another state automatically. This allows units to be placed in the discoverable state for a limited time
period.
•
Read and write to GPIO lines
•
Read the ADC channel
•
Get fast GPIO and ADC status through an inquiry response (patent pending)
7.3.1.2
UART
•
Change the baud rate from 1200 to 921,600 baud.
•
Use the DSR line to drop connections
•
Flexible configuration as either DTE or DCE
•
Change escape sequence character
•
Change the Parity
•
Enable or disable echoes
7.3.1.3
Security
•
Enable Authentication by requiring a PIN code for incoming AND / OR outgoing connections
•
Enable data to be encrypted over the air for incoming AND / OR outgoing
connections. The module can be configured to be:
non-connectable and non-discoverable,
non-connectable but discoverable,
connectable but non-discoverable,
connectable and discoverable.