DS-41SMD-2 June ’06

©2006 RF Solutions Ltd, www.rfsolutions.co.uk

Page 4

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Embedded GPS Module

GPS-41SMDR

GPS-41SMDF

PINOUT DESCRIPTION

Pin Number

Signal Name

I/O

Description

1

NC

-

No connection

2

NC

-

No connection

3

TXD0

O

3.3V LVTTL async serial output, to output NMEA message

4

RXD0

I

3.3V LVTTL async serial input, to input binary commands

5

NC

-

No connection

6

DVCC

-

Regulated 3.3V supply input for digital section

7

GND

-

Ground

8

NC

-

No connection

9

NC

-

No connection

10

RESETN

I

Manual reset input, active LOW. Leave open if not used.

11

VCC BAT

-

2.0V ~ 3.9V supply voltage to sustain RTC and SRAM data. Connect to

GND if not used; will cold start every time.

12

NC

-

No conection

13

RF GND

-

RF ground

14

RF GND

-

RF ground

15

RF GND

-

RF ground

16

RF IN

I

GPS signal input. 50Ω impedance.

17

RF GND

-

RF ground

18

VCC RF

-

Regulated 3.3V supply voltage for the RF section

19

VCC ANT

-

Power input for active antenna. Leave open if not used.

20

NC

-

No connection

21

NC

-

No connection

22

NC

-

No connection

23

NC

-

No connection

24

BAUD SEL0

I

Baud rate selection 0

25

BAUD SEL1

I

Baud rate selection 1

BAUDSEL[1:0] 00

4800 baud

01

9600 baud

10

19200 baud

11

38400 baud

26

GPIO11

(LED)

O

3.3V GPIO, default used for GPS status indication

27

NC

-

No connection

28

P1PPS

O

1 pulse per second time mark

1PPS Output

The GPS receiver is in navigation mode upon power-up, with 1PPS output free running. After 3 minutes of valid

position fix and remaining under static-mode, the receiver changes to timing-mode, with 1PPS output signal

synchronized to the UTC second. The receiver will change to navigation-mode, with 1PPS output free running,

if the receiver is in motion. The 1PPS output will become synchronized to the UTC second again after the

receiver had remained in static mode for 3 minutes.