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13.3 SCENARIO 3: POINT-TO-MULTIPOINT CON-
NECTION
LMX9820 acts as master for several slaves.
Example:
Two sensors with LMX9820; one hand-held
device with implemented LMX9820.
Serial Devices #2 and #3 establish the link automatically as
soon as they are contacted by another device. No control-
ler interaction is necessary for setting up the Bluetooth link.
Both switch automatically into Transparent mode. The host
sends raw data over the UART.
Serial Device #1 is acting as master for both devices. As
the host has to decide to or from which device data is com-
ing from, data must be sent using the “Send data com-
mand”. If the device receives data from the other devices, it
is packaged into an event called “Incoming data event”.
The event includes the device related port number.
If necessary, a link configuration can be stored as default in
the master Serial Device #1 to enable the automatic recon-
nect after reset, power-up, or by sending the “connect
default connection” command.
Figure 20. Point-to-Multipoint Connection
Microcontroller
LMX9820
Connect to Device #2
Connection Request
Transparent Mode
LMX9820
Serial Device #1
Connect to Device #2
Microcontroller
Serial Device #2
see Scenario 2
see Scenario 2
Automatic Link Setup
Connected
on Port L
Send Data Command
Receive Data Event
Send Data to Port L1
Data Received
from Port L1
Link Established
Link Established
on Port L1
Microcontroller
LMX9820
Connection Request
Transparent Mode
Serial Device #3
Automatic Link Setup
Connected
on Port L
Connect to Device #3
Connect to Device #3
see Scenario 2
see Scenario 2
Send Data Command
Receive Data Event
Send Data to Port L2
Data Received
from Port L2
Link Established
Link Established
on Port L2
Air
Interface
Raw Data
Raw Data