www.rovingnetworks.com
4
RN -BT -SR L-U M- 1.0
Reducing Power when Disconnected
Low-power connection mode disables the Bluetooth radio and LED timers when the adapter is disconnected. In low-power
mode, the adapter cycles between active (discoverable and connectable) and low power deep sleep. This mode saves
considerable power when the module is waiting for long periods of time without a connection. The trade off is additional
latency when connecting or pairing. Refer to the
Bluetooth
Advanced User Manual
on the Support page of the Roving
Networks website at
http://www.rovingnetworks.com/Support_Overview
for more information on using the low-power
connection mode.
STATUS LEDS
The adapters have several LED indicators. The green LED shows the Bluetooth connection status and the adapter’s
operational mode:
•
When booting, the LED blinks two times per second.
•
In configuration mode, it blinks ten times per second.
•
When the module is in discoverable or idle mode, it blinks one time per second.
•
When the module is connected, the green LED is on solid.
The yellow LED blinks when data is sent or received on the serial interface. This blinking does not indicate that data was
sent over the Bluetooth connection. If the yellow LED is not blinking when your device sends data to the serial port, the
connection or flow control may be set incorrectly.
Some versions of the RN-240 adapter have a red LED. This LED blinks when data is received over the RF link in low-speed
data mode.
OPERATING MODES
The Bluetooth adapter has several operating modes, which you set using the
SM
command in command mode:
•
Slave (SM,1)
—Default mode, whereby other Bluetooth devices can discover and connect to the adapter.
•
Master (SM,1)
—In this low-speed connection mode, the adapter makes connections when a connect command
(
C
), is received. This command can also contain the Bluetooth address of the remote device. If a device is not
specified, the adapter uses the stored remote address. The connection can be broken if the special break
character or string is sent (use the
SO
command to set the break character).
•
Trigger (SM,2)
—In this low-speed connection mode, the adapter makes connections automatically when a
character is received on the serial port. The connection continues as long as characters are received on either
end. The adapter has a configurable timeout (which you set using the
ST
command) that disconnects the
adapter after the specified number of seconds (1 to 254) of inactivity.
•
Auto Master (SM,3)
—In this mode, the adapter makes connections automatically on power-up, and re-connects
when the connection is lost. You can also enable this mode using switch 2. This mode is a high-speed
connection mode, and cannot be broken by software break characters.
NOTE:
In all master modes, the device cannot be discovered or configured remotely over Bluetooth.
