Using various GPS boards to provide NMEA serial data for APRS units,
or to provide a 1PPS signal for locking 10 MHz reference sources,
or other  RF reference signals, such as ProgRock from QRP Labs,
for use with weak signal digital modes such as WSJT/WSPR, where
there is requirement for high stability and frequency accurate radios.

If you looking for 1PPS output, you need to look for boards that have
the Ublox NEO-6T or NEO-8T chip, or have the Telit Jupiter F2 (JF2) chip,
or a Trimble 36576 board (as used on the SRM9000 Dispatcher board).


CRIUS NEO-6m GPS board

Features:

- U-blox NEO-6M GPS module
- 5Hz update rate
- 32k I2C EEPROM for save configuration
- Build in 25 x 25 x 4mm ceramic patch antenna
- LNA and SAW chip
- 3.3V LDO low noise regulator
- UART (TTL) port with EMI protection
- 3V lithium Rechargeable battery
- Power and Fix (gps lock) indicator LEDs
- Reverse polarity protection for input power

Specification:

- Standard NMEA 0183 protocol, or its can run OSP protocol
- Baud rate : 9600
- Nav rate : 1Hz
- TIMEPULSE (fix LED) rate : 1Hz
- Dimension: 40 x 40 x 9mm
- Weight: 16.4g/18.6g (include cable)
- Hole diameter: 3.1mm

Pinouts:
4 pin header
 VCC - (RED) 5v DC
 TXD - (YELLOW)  UART output
 RXD - (GREEN)  UART input for programming GPS
 GND - (BLACK) 0v

 Options:
 12C-GPS Nav Module (for RC model equipment)

 Programming:
 Ublox U-Center Developers tool for setting speed/protocol
 (currently v8.26) doesn't work on WinXP
 










Telit Jupiter F2 (JF2) GPS Module with Active Antenna

Uart TTL Output, NMEA 0183 protocol, default Baud Rate 9600, 1Hz
Can also do OSP protocol, typically 115kBaud
1PPS Output: When GPS module has lock.

Note: This is GPS Module with Active Antenna,
chip used is Telit Jupiter F2 (JF2) GPS, low power, SiRF IV comaptible.

Size: 28mm*28mm*8.5mm

Led Indicators:  Tx Led and 1PPS Led

Pinouts:
1) VCC -(BLUE), 2.8V to 5.5V DC
2) GND - (GREEN), 0v
3) RX - (YELLOW), for programming GPS
4) TX - (BLACK),  UART output, baud rate is 4800 (but not by default)
5) 1PPS - (RED), will output 1PPS signal every 1 second. The signal is active high 100ms pulse.

Accessories :  5 pin, 1.25 Cable

Programming:
via UART or the SPI interface, configure Control pins to define which port is used.