RN-21-U Roving Networks Inc, RN-21-U Datasheet - Page 18
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RN-21-U
Manufacturer Part Number
RN-21-U
Description
MODULE BLUETOOTH 2.0/EDR CLASS1
Manufacturer
Roving Networks Inc
Specifications of RN-21-U
Frequency
2.4GHz Center
Data Rate - Maximum
921kBaud
Modulation Or Protocol
FHSS
Applications
Bluetooth v2.0
Power - Output
16dBm
Sensitivity
-86dBm
Voltage - Supply
3 V ~ 3.6 V
Current - Receiving
60mA
Current - Transmitting
100mA
Data Interface
PCB, Surface Mount
Memory Size
8MByte Flash
Antenna Connector
PCB, Surface Mount
Operating Temperature
-40°C ~ 85°C
Package / Case
Module
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
5.4 Disabling Output Drivers
5.5 Lowering Transmit Power
www.rovingnetworks.com
To enable even lower power utilization, use the S|, <hex word> command to set an on/off duty cycle.
All Roving Networks Bluetooth modules and adapters adhere to the Bluetooth (1.1, 1.2, and 2.0/2.1)
specifications for power control. Both the RN-21 and RN-41 radios are Class 1 capable.
The power output of the radio is automatically controlled by the baseband. Depending on the operation mode
(inquiry scan, page scan, connected) the power is adjusted. Once a connection is made, the radios on both
sides negotiate a power setting based on the perceived signal strength (RSSI).
The transmit power can be controlled to:
Use the SY command can be used to configure the transmit power: Using a command, the radio can be
instructed to use a value that is lower than the default.
SY,<hex value> where hex value is unsigned hex representation of the setting.
If a non-zero value is stored in the variable, then upon power up, the radio will use the HIGHEST value that
is less than or equal to the stored variable.
Example: if -8 = 0 dBM is desired, you would enter SY,FFF8
If 0 = 6dBm is desired, you would enter SY,0001 ( you could also enter 0002, or 0003 )
Power setting will take effect after power cycle or reboot or reset pin toggle.
To check the STORED power setting, use the O command. you will see TX Power=1 or other setting equal
to the value you entered. To check the current power setting, use the GY command. Only the actual value
Use the command “ S%,1000” to set all PIO0-11 to inputs.
This will also turn off the LED (PIO5) on the FireFly adapter.
809 University Avenue
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•
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reduce effective range for security reasons
lower radio emissions for agency compliancy concerns
reduce total power consumption
Setting
-24
-16
-12
-8
-4
0
4
•
Los Gatos, CA 95032
Hex value
FFFC
FFE8
FFF0
FFF4
FFF8
0001
0004
~ 18 ~
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Tel (408) 395-6539
Approximate output (dBM)
rn-bluetooth-um Version 4.77 1/24/2011
12 (default)
Advanced User Manual
-20
-10
-5
0
2
6
• info@RovingNetworks.com