RN-24E Roving Networks Inc, RN-24E Datasheet - Page 21

• Manufacturer Part Number: RN-24E
• Description: SUPERMODULE BLUETOOTH SMA JACK
• Manufacturer: Roving Networks Inc

Specifications of RN-24E

• Frequency: 2.4GHz
• Data Rate - Maximum: 721kbps
• Modulation Or Protocol: Bluetooth v2.0+EDR, Class 1 & 2
• Applications: Bluetooth v2.0
• Power - Output: 4dBm
• Sensitivity: -80dBm
• Voltage - Supply: 4 V ~ 24 V
• Current - Receiving: 40mA
• Current - Transmitting: 40mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: SMA
• Package / Case: Module
• Wireless Frequency: 2.402 GHz to 2.48 GHz
• Interface Type: UART
• Data Rate: 240 Kbps to 300 Kbps
• Modulation: FHSS, GFSK
• Operating Voltage: 3.3 V
• Antenna: SMA Jack
• Board Size: 20.32 mm x 50.8 mm x 4.08 mm
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Operating Temperature: -
• Memory Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 740-1009

7
7.1 Hardware Signals
7.2 Hardware Connections and Power
Design Concerns
www.rovingnetworks.com
1. RESET circuit. RN-41 contains a 1k pullup to VCC, the polarity of reset on the RN41 is ACTIVE LOW.
RN21/22 contain a 1k pulldown, and the reset polarity is ACTIVE HIGH.
A power on reset circuit with delay is OPTIONAL on the reset pin of the module. It should only be required
if the input power supply has a very slow ramp, or tends to bounce or have instability on power up. Often a
microcontroller or embedded CPU IO is available to generate reset once power is stable. If not, there are
many low cost power supervisor chips available, such as MCP810T, MCP102/121, and Torex XC61F.
2. Factory reset PIO4. It is a good idea to connect this pin to a switch, or jumper, or resistor, so it can be
accessed. This pin can be used to reset the module to FACTORY DEFAULTS and is often critical in
situations where the module has been mis-configured.
3. CONNECTION status. PIO5 is available to drive an LED, and blinks at various speeds to indicate status.
PIO2 is an output which directly reflects the connection state, it goes HIGH when connected, and LOW
otherwise.
4. Using SPI bus for flash upgrade. While not required, this bus is very useful for configuring advanced
parameters of the Bluetooth modules, and is required for upgrading the firmware on modules. The suggested
ref-design shows a 6pin header which can be implemented to gain access to this bus. A minimum-mode
version could just use the SPI signals (4pins) and pickup ground and VCC from elsewhere on the design.
Placing 3.3Vdc into the PIO’s while they are set as outputs will permanently damage the radio
modules. The failure mode is short across GND and VCC. Use a 10K
pull up resistor for input and output PIO’s respectively.
Hardware Communications Connections for Modules and Eval Board
Radio TX
Radio RX     TX of the application Micro Controller Unit (MCU)
Radio RTS
Radio CTS     RTS of the application Micro Controller Unit (MCU)
809 University Avenue
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Make sure to connect a common ground when using the external TX, RX inputs 0 – 3.3Vdc.
For a 3 wire DB-9 interface (tx, rx, gnd only) connect/short CTS to RTS, Factory default is hardware
flow control enabled CTS and RTS connected.
When using a 5.0Vdc Input, PIO’s require a voltage divider. A good choice is 10K ohm series with
20K to Ground. PIO’s are 0-3.3Vdc not 5 volt tolerant.
RX of the application Micro Controller Unit (MCU)
CTS of the application Micro Controller Unit (MCU)
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rn-bluetooth-um Version 4.77 1/24/2011
Advanced User Manual
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resistor in series or a 10K