Pin

Name

I/O

Description

1

GND

-

Power supply and signal ground. Connect to the host circuit board ground.

2

ACTIVITY

O

RF activity indicator. Output pulses high when a packet is sent or received.

3

LINK

O

Link indicator. Output is high when the radio has successfully joined a network.

4

GPIO0

(ADC_REF)

I/O

Configurable digital I/O port 0. When configured as an output, the power-on state is also configurable. This pin can also

be configured as a reference voltage input for the ADCs, 0 to 3.3 V, 1.25 V typical.

5

RADIO_TXD

O

Serial data output (UART) from the radio to the host.

6

RADIO_RXD

I

Serial data input (UART) from the host to the radio.

7

GPIO4

(/HOST_CTS )

I/O

Configurable digital I/O port 4. When configured as an output, the power-on state is also configurable. Also configurable

as UART flow control output. The LPR2430 sets this line low to indicate it is ready to accept data from the host on the

RADIO_RXD input. When the LPR2430 sets this line high, the host must stop sending data. The default state is GPIO4.

8

GPIO5

(/HOST_RTS)

I/O

Configurable digital I/O port 5. When configured as an output, the power-on state is also configurable. Also configurable

as UART flow control input. The host sets this line low to allow data to flow from the RADIO_TXD pin. When the host sets

this line high, the LPR2430 will stop sending data to the host. The default state is GPIO5.

9

PWM0

O

Pulse-width modulated output 0 with internal low-pass filter. Provides a DAC function, 0 to 3.3 V.

10

GPIO2

(PWM1)

I/O

Configurable digital I/O port 2. When configured as an output, the power-on state is also configurable. This pin is con-

nected to the input of the low-pass filter driving Pin 13, and is also configurable as a PWM output.

11

GPIO1

I/O

Configurable digital I/O port 1. When configured as an output, the power-on state is also configurable.

12

GPIO3

(RS485_EN)

I/O

Configurable digital I/O port 3. When configured as an output, this high current port can sink up to 20 mA. The power-on

output state is also configurable. Can also be configured as active low transmit enable for controlling an RS485 or other

half-duplex bus driver.

13

PWM1

(GPIO2)

O

GPIO2 (Pin 10) drives this pin through a low-pass filter. Provides a DAC function when GPIO2 is configured as a PWM

output.

14

VCC

I

Power supply input, +3.3 to +5.5 Vdc.

15

GND

-

Power supply and signal grounds. Connect to the host circuit board ground.

16

GND

-

Power supply and signal grounds. Connect to the host circuit board ground.

17

/RESET

I

Active low module hardware reset. Hold this input low when the power supply input is less than 3.3 Vdc. The module firm-

ware boots up and will accept commands about 3 seconds after this input goes high.

18

ADC0

I

11-bit ADC input 0. ADC full scale reading can be referenced to the module’s +3.3 V regulated supply, the ADC’s internal

+2.5 V reference, or ADC_REF (Pin 4).

19

ADC1

I

ADC input 1. Same configuration options as ADC0.

20

RSVD

-

Reserved pin. Leave unconnected.

21

RSVD

-

Reserved pin. Leave unconnected.

22

RSVD

-

Reserved pin. Leave unconnected.

23

RSVD

-

Reserved pin. Leave unconnected.

24

ADC2

I

ADC input 2. Same configuration options as ADC0.

25

ADC_VDD

O

Module’s +3.3 V regulated supply, used for ratiometric ADC readings. Current drain should be less than 5 mA.

26

NC

-

No connection.

27

NC

-

No connection.

28

GND

-

RF ground. Connect to the host circuit board ground plane, and to shield when using coaxial cable.

29

RFIO

I/O

RF port. Connect the antenna to this port with a 50 W stripline or semi-rigid coaxial cable.

30

GND

-

RF ground. Connect to the host circuit board ground plane, and to shield when using coaxial cable.

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©2009 by RF Monolithics, Inc.

LPR2430 - 06/19/09

LPR2430 I/O Pad Descriptions