GPS-NX02 Receiver

An adapter cable is required to connect
the GPS to the telescope for power and data

· Fast time-to-first-fix and low power consumption
· High performance 65-channel SkyTraq chipset
· Supports standard NMEA-0183, Meade LX200, Celestron NexStar, Synta Binary and Vixen HTTP protocols
· Automatically detects telescope type (Meade, Celestron, Synta, Vixen or none)
· Switches to standard 4800 baud NMEA output after 45 seconds if no telescope is detected
· Lithium cell sustains internal clock and memory (recharges during normal operation)
· LED power indicator blinks to indicate receiver status (see General Information)
· Automatic cold start with no user initialization required
· Compact design with integrated antenna/receiver
· One-year warranty (parts & labor)

· Size: 39 x 45 x 16 mm (1.5" x 1.8" x 0.6")
· Weight: 60 g (2.1 oz)
· 65-channel (-159 dBm sensitivity)
· Warm start in 35 seconds, cold start in 42 seconds
· Update rate: 1 second (default), adjustable*
· Position accuracy: 2.5 meters CEP
· Velocity: 0.1 meters/second
· Time: +/- 100 nanosecond synchronized to GPS time
· Altitude: 18,000 meters (60,000 feet) max
· Velocity: 515 meters/second (1000 knots) max
· Acceleration: 4 G, max
· Interface: RS-232 with 1.5 m (60") cable (PS/2 Female)
· Baud rate: 9600 (default), 4800, 19200, 38400*
· NMEA-0183 Version 3.01 ASCII output: GPGGA, GPGSA, GPGSV, GPRMC, GPVTG
· Meade LX200 Command Set
· Celestron NexStar Communication Protocol (requires hand control firmware version 2.3, 104.0 or 4.0+)
· Synta Binary Protocol (requires hand control firmware version 3.10+)
· Vixen HTTP Protocol (requires firmware version 1.2 build 31 or newer)
· User selectable NMEA sentences also include: GPGLL, GPZDA*
· Power: 3.6 to 5.5 V @ 45 mA tracking, 80 mA acquisition
· Backup power: 3V rechargeable lithium cell (350 hours)
· Operating temperature: -40 to +85°C (-40 to +185°F)
· Relative humidity: 5% to 95% non-condensing

(Software not included, requires GPS-USB)
· Delorme Street Atlas
· Fugawi
· OziExplorer
· any software that supports the NMEA-0183 protocol


* A GPS-USB cable is required to adjust the output settings.

GPSView allows you to change the GPS-NX01 and GPS-NX02 output settings for use with other software. In most cases this is not necessary since the GPS will automatically switch to NMEA output after 30 seconds (GPS-NX01) or 45 seconds (GPS-NX02) if a telescope is not detected (see table below).

  1. Plug the GPS-USB cable into your PC. Windows Update will use your internet connection to locate and install the appropriate driver. If necessary you can also download and install the PL2303 driver from
    This allows the USB port to operate as a virtual COM port.
  2. Connect the GPS to the GPS-USB cable.
  3. Verify that the GPS LED is turned on (it should be getting power from the PC).
  4. Download and run the GPSView program from
  5. Select the GPS type, Serial port and 4800 baud.
  6. Click on the "Open Port" button.
  7. Wait until you see NMEA messages (occurs within 30 or 45 seconds of power on).
  8. Choose the output settings that you want and then click "Set NMEA".
  9. You will see NMEA messages being output.
  10. The GPS is now configured. Note that a GPS-NX01 will only maintain these settings as long as the internal battery is charged. Otherwise the output settings will revert to the default rates listed below.
  11. IMPORTANT - the baud rate must be set to 9600 to operate in telescope mode (default).

Message default no telescope
GGA 0 1
GLL 0 0
GSA 0 3
GSV 0 3
RMC 0 1
VTG 0 1

NOTE: The GPS will operate in telescope mode if all NMEA sentences are turned off (0). In this mode the GPS will attempt to determine the telescope communication protocol (Meade, Celestron, Synta or Vixen). If no telescope is found after 30 seconds (GPS-NX01) or 45 seconds (GPS-NX02) the GPS LED will blink rapidly for 5 seconds and NMEA output will begin at 4800 baud as shown in the above table.



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