LMX9820ASM NSC [National Semiconductor], LMX9820ASM Datasheet - Page 33

• Manufacturer Part Number: LMX9820ASM
• Description: Bluetooth Serial Port Module
• Manufacturer: NSC [National Semiconductor]

Revision 1.0
13.0 Usage Scenarios
13.2 SCENARIO 2: AUTOMATIC POINT-TO-POINT
CONNECTION
LMX9820A at both sides.
Example: Serial Cable Replacement.
Device #1 controls the link setup with a few commands as
described.
1. Port R indicates the remote RFComm channel to connect to. Usually the result of the SDP request.
2. Port L indicates the Local RFComm channel used for that connection.
Serial Device #1
6. Switch to
Bluetooth device controls link with
1. Devices in Range?
2. Choose the Device
3. Which COM Port is
4. Create SPP Link
5. Connect on Default
SDP Link Established
to Port R1 on Port L2
Connected on Port L
Store Default Device
SDP Link Released
(Optional)
Establish SPP Link
Establish SDP Link
RFComm Port = R
Release SDP Link
Transparent
Transparent Mode
available?
Service Browse
Device Stored
Inquiry Result
Microcontroller
Inquiry
a few commands.
(Continued)
Figure 20. Automatic Point-to-Point Connection
Storing Default Device
SDP Link Established
SDP Link Released
Establish SPP Link
to Port R on Port L
Establish SDP Link
Release SDP Link
Transparent Mode
Link Established
Service Browse
Browse Result
Device Stored
Inquiry Result
LMX9820A
Inquiry
Raw Data
Interface
33
Air
If step 5 is executed, the stored default device is connected
(step 4) after reset (in automatic mode only) or by sending
the “Connect to Default Device” command. The command
can be sent to the device at any time.
If step 6 is left out, the microcontroller has to use the “Send
Data” command, instead of sending data directly to the
module.
Serial Device #2
only “connected” event indicated to controller.
Transparent Mode
SDP Link Request
Service Response
Release SDP Link
SPP Link Request
Inquiry Response
SPP Link Accept
No Bluetooth commands necessary;
SDP Link Accept
Release Confirm
Inquiry Request
Service Browse
LMX9820A
Microcontroller
on Port R
Connected
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