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  • 28504: SIM33EAU GPS Module - front view
  • 28504: SIM33EAU GPS Module - back view
  • 28504: SIM33EAU GPS Module - alternate view
Product ID: 28504


Whether your project needs positional accuracy, high-speed movement estimations, high altitude measurements, fast update rates, or just plain ease of use, the SIM33EAU GPS Module has you covered.

Parallax’s SIM33EAU GPS Module embeds the capable SIM33EAU GPS device in a project-friendly board. Ultra compact, the SIM33EAU device has a built-in low-noise amplifier and patch antenna so there is no need for an extra antenna on the board.

The SIM33EAU GPS device gives your project the ability to read its position on the earth—given a clear view of the sky—using global navigation satellite systems such as GPS, GLONASS, Galileo or QZSS. Its default settings provide all the capabilities you would expect from a GPS receiver: location fix, speed, heading, altitude measurements, and atomic date and time. Advanced users can re-configure these settings for specific needs.

Parallax’s module makes the SIM33EAU device  easily accessible to students, hobbyists, and developers.  An onboard voltage regulator and buffer circuitry provide signal conditioning for use with 3.3 V or 5 V microcontrollers. Power and satellite fix LEDs let you know when your GPS module is ready and  receiving data.  A supercapacitor preserves almanac data for more than two hours if power is disconnected. The breadboard-friendly 7-pin header and mounting holes make for quick, solder-free integration into a project.


  • Ready  for use with 3.3 V or 5 V microcontrollers
  • Power and satellite fix LEDs for quick visual status
  • Supercapacitor preserves almanac data for more than 2 hours
  • Supports PMTK and NMEA 0183 standard protocols
  • Receiver supports GPS, GLONASS, GALILEO, QZSS, SBAS ranging (WAAS/EGNOS/MSAS/GAGAN), AGPS,  and EASY/EPO orbit prediction
  • 33 tracking & 99 acquisition channels with jamming elimination
  • Indoor and outdoor multi-path detection and compensation

Application Ideas

  • Robot navigation
  • Fleet tracking
  • Heading and speed measurements
  • Weather balloon tracking

Note: Propeller C code for this GPS module requires Simple Libraries update 07.02.2019 or later.



  • Power: 3.3 V – 5 V*, 60 mA max (typically 45 mA)
  • Standby power: Typically 165 µA at 3.3 VIN, 287 µA at 5 VIN
  • Supercapacitor data preservation time for hot start: >2 hours
  • Channels: 33 tracking, 99 acquisition
  • Typical TTFF (Time to first fix): Cold 31 s, Warm 26 s, Hot < 1 s, EPO Assist 13 s
  • Protocols: NMEA and PMTK
  • Communication: TTL Asynchronous Serial UART 4800–115200 bps, 9600 default
  • Digital I/O: Enable, 3D-Fix and Timemark (1 PPS - Pulse Per Second)
  • Navigation update rate: up to 10 Hz
  • Horizontal position accuracy: 2.5 meter CEP (Circular Error Probable)
  • Speed accuracy: 0.1 meter/second
  • Operating temperature range: -40 to +185 °F (-40° to +85° C)
  • Maximum altitude: 80 km (~50 mi); upper mesosphere
  • Dimensions: 1.0 x 1.7 x 0.36 in (25.4 x 43.2 x 9.1 mm)

Note: Propeller C code for this GPS module requires Simple Libraries update 07.02.2019 or later.

Rev A Note: When VIN is connected to 5V, connect a series diode between VIN and 5V to enable the PPS and FIX output pins.
Use a common diode such as 1N4001, 1N4148 or 1N5818. Connect the Anode to your 5V supply and the Cathode to the GPS module VIN pin.  Not necessary with Rev B.

Downloads & Documentation

Product Specific Downloads
Download Details More Info
SIM33EAU GPS Module Schematic - 131.03 KB | updated: 19 May 2020 - 2:03 pm
SIM33EAU GPS Module Product Guide - 1.18 MB | updated: 04 May 2020 - 2:51 pm
MT337 Platform NMEA Message Spec for GPS + GLONASS - 1.15 MB | updated: 29 Aug 2019 - 1:30 pm
SIM33EAU GPS Device Manufacturer Specification - 192.1 KB | updated: 29 Aug 2019 - 1:26 pm
Propeller C Learn Folder - 10.07 MB | updated: 02 Mar 2020 - 5:24 pm

Additional Resources