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The FPGA4U-NAV is an extension board (daughter board) for the FPGA4U. At the moment, FPGA4U-NAV is equipped with a GPS module and an array of accelerometers/magnetometers. The goal of this project is to develop a powerful and flexible hardware experimental platform that can be used to investigate several research aspects of indoor and outdoor navigation.

FPGA4U-NAV is a project by Fabrizio Tappero from the ENAC-TOPO group. The EPFL ENAC-TOPO group welcomes any interested student or academic to take part to its development.


The FPGA4U-NAV is an extension board which plugs on top of the FPGA4U and communicates with it through the 64 pin ieee 1386 Molex connector. An overview of the FPGA4U-NAV board and the FPGA4U board is presented in the following schematic.

Block diagram of the FPGA4U-NAV.

What is this board for?

The FPGA4U-NAV board represents an experimental platform for research purposes on navigation methods and algorithms currently carried on at the ENAC-TOPO group.

The main research objectives of the FPGA4U-NAV board are:

  • GPS and low-cost INS Integration for navigation
  • Navigation with redundant low-cost INS sensors (accelerometer, gyroscope, magnetometer, etc.)
  • Navigation with image and optical flow sensors
  • FPGA development for navigation

The following subsections give an overview of the components available on this board.


The GNSS receiver module selected for this project is the u-blox Antaris 5 GPS module LEA-5T.

Details can be found here.

The LEA-5T supports raw data output at an update rate of 10 Hz. The UBX-RXM-RAW message includes carrier phase with half-cycle ambiguity resolved, code phase and Doppler measurements, which can be used in external  applications that offer precision positioning, real-time kinematics (RTK) and attitude sensing.  

U-blox Antaris 5 GPS Module LEA-5T

  • 50-channel u-blox 5 engine with over 1 million effective correlators
  • Under 1 second Time-To-First-Fix for Hot and Aided Starts
  • SuperSense® Indoor GPS: -160 dBm tracking sensitivity
  • Supports AssistNow Online and AssistNow Offline A-GPS services; OMA SUPL compliant
  • Operating temperature range: -40 to 85°C
  • RoHS compliant (lead-free)

Gyroscope Array

The gyroscope array is made of six gyroscopes Analog Devices ADIS16060, ±80°/sec Yaw Rate Gyro with SPI Interface. Details can be found here.

Gyroscope ADIS16060

  • Complete angular rate gyroscope
  • Z-axis (yaw rate) response
  • SPI digital output interface
  • High vibration rejection over wide frequency
  • 2000 g-powered shock survivability
  • Externally controlled self-test
  • Internal temperature sensor output
  • Dual auxiliary 12-bit ADC inputs
  • Absolute rate output for precision applications
  • 5 V single-supply operation
  • 8.2 mm × 8.2 mm × 5.2 mm package
  • RoHS compliant


The magnetometer is a 3-Axis digital magnetometer Honeywell HMC5843. Details can be found here.

Honeywell HMC5843 features

  • 3-Axis Magnetoresistive Sensors and ASIC in a Single Package
  • 4.0 x 4.0 x 1.3mm Low Height Profile
  • Low Voltage Operations (2.5 to 3.3V)
  • Digital Interface, I2C digital interface
  • Wide Magnetic Field Range (+/-6 Oe) 4
  • Sensors Can Be Used in Strong Magnetic Field Environments

Accelerometers Array

The accelerometers array is made of six 3-Axis digital accelerometers Analog Devices ADXL345. Details can be found here.

Analog Devices ADXL345 Features

  • Ultra low power: 25 to 130 µA at VS = 2.5 V (typ)
  • Power consumption scales automatically with bandwidth
  • User selectable fixed 10-bit resolution or 4mg/LSB scale factor in all g-ranges, up to 13-bit resolution at ±16 g
  • 32 level output data FIFO minimizes host processor load
  • Built in motion detection functions
    • Tap/Double Tap detection
    • Activity/Inactivity monitoring
    • Free-Fall detection
  • Supply and I/O voltage range: 1.8 V to 3.6 V
  • SPI (3 and 4 wire) and I2C digital interfaces
  • Flexible interrupt modes – Any interrupt mappable to either interrupt pin
  • Measurement ranges selectable via serial command
  • Bandwidth selectable via serial command
  • Wide temperature range (-40 to +85°C)
  • 10,000 g shock survival
  • Small and thin: 3 × 5 × 1 mm LGA package

SD Card

the SD card slot provides storage up to some GB of data. Read and Write function is implemented in the FPGA.

Additional Components

the board FPGA4U-NAV is equipped with additional modules that are not normally employed for navigation.

C3088 1/4” Colour Camera

The C3088 is a 1/4” color camera module with digital output. It uses OmniVision’s CMOS image sensor OV6620. Combining CMOS technology together with an easy to use digital interface makes C3088 a low cost solution for higher quality video image application. The digital video port supplies a continuous 8/16 bit-wide image data stream. All camera functions, such as exposure, gamma, gain, white balance, color matrix, windowing, are programmable through I2C interface. In combine with OV511+, USB controller chip, it will be easily form a USB camera for PC application." Camera with lens f3.6mm, F2.0 Weight: 14 grams (0.49 oz)

Details of the optic sensor can be found here.

Agilent ADNS-2051 Optical Flow Sensor

The ADNS-2051 is a low cost optical sensor used to implement a non-mechanical tracking engine for computer mice. It is based on optical navigation technology, which measures changes in position by optically acquiring sequential surface images (frames) and mathematically determining the direction and magnitude of movement. Default resolution is specified as 400 counts per inch (cpi), with rates of motion up to 14 inches per second (ips). Details if this sensor can be found here.

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