1300 Henley Court Pullman, WA 99163 509.334.6306 www.digilentinc.com Pmod NAV Reference Manual Revised January 17, 2017 This manual applies to the Pmod NAV rev. C Overview The Digilent Pmod NAV (Revision C) uses the LSM9DS1 3-axis accelerometer, 3-axis gyroscope, 3-axis magnetometer, plus the LPS25HB digital barometer to provide users with 10-DOF functionality. 1 Functional Description The Pmod NAV provides a variety of orientation related data allowing users to easily determine the exact position the module is in and where it is headed. With 16-bit full scale registers for acceleration, rotation, and orientation, and 24 bits of resolution for pressure data, users can easily figure out if their moving robot is falling over, how high in the air their hot air balloon is located, or which direction they are facing. Features: 2/4/8/16 g linear acceleration full scale 245/500/2000 dps angular rate full scale 4/8/12/16 gauss magnetic full scale 260-1260 hPa piezoresistive pressure sensor Embedded temperature sensors for compensation 12-pin Pmod connector with SPI interface Follows Digilent Interface Specification Type 2A The Pmod NAV. 2 Interfacing with the Pmod The Pmod NAV communicates with the host board via the SPI protocol. By pulling the appropriate chip select line low (either for the Accelerometer/Gyroscope, the Magnetometer, or the Barometer) users may collect data from any of the four available sensors on the Pmod NAV. The accelerometer provides full-scale 16-bit signed data for all three Cartesian axes. All of the data is measured as linear acceleration since each axis is measured individually and are all isolated from each other. Gyroscopes Copyright Digilent, Inc. All rights reserved. DOC : 510-326 Page 1 of 3 Other product and company names mentioned may be trademarks of their respective owners. Pmod NAV Reference Manual measure the angular rotation rate of the module, indicating the degrees per second that the module is being rotated around each axis. The magnetometer detects the magnetic field present around the module, including both the earth s magnetic field as well as the local magnetic environment around it. Each of the three magnetic axis registers provide signed 16-bit full-scale data with up to 16 gauss sensitivity. Before using the magnetometer, users should run a calibration routine (available in the code example on the Pmod NAV Resource Center) to correct for any hard iron biases that may be present around them. The final component on the Pmod NAV is a barometer with an absolute pressure range of 260 to 1260 hPa which is approximately equivalent to 0.25 to 1.25 atm. Note that as a piezoresistive pressure sensor on the Pmod NAV, you can only measure air pressure with the barometer rather than being able to also measure water pressure. 3 Pin Description Tables Pin Signal Description 1 CS A/G Chip select for Accel/Gyro 2 SDI Master Out Slave In (MOSI) 3 SDO Master In Slave Out (MISO) 4 SPC Serial Clock 5 GND Power Supply Ground 6 VCC Power Supply (3.3V/5V) 7 INT Interrupt pin for all components 8 DRDY M Data ready for the Magnetometer 9 CS M Chip Select for the Magnetometer 10 CS ALT Chip Select for the Altimeter 11 GND Power Supply Ground 12 VCC Power Supply (3.3V/5V) Table 1. Header J1 pin descriptions. Pin Signal Description 1 INT M Interrupt for the Magnetometer 2 INT ALT Interrupt for the Altimeter Table 2. Header J2 pin descriptions. Pin Signal Description 1 INT1 A/G Interrupt 1 for Altimeter/Gyroscope 2 DEN A/G Data Enable for Altimeter/Gyroscope Table 3. Header JP1 pin descriptions. The Pmod NAV reports to the host board when users bring the appropriate chip select line low to then read the data from the registers on the LSM9DS1. Any external power applied to the Pmod NAV must be within 1.9V and 3.6V however, it is recommended that Pmod is operated at 3.3V. Copyright Digilent, Inc. All rights reserved. Page 2 of 3 Other product and company names mentioned may be trademarks of their respective owners.