Library for communicating with uBlox GPS receivers using Teensy 3.x and Teensy LC devices.
uBlox produces standard and high precision GPS receivers with options for RTK, PPP, and multi-constellation GNSS. These receivers feature high sensitivity, minimal acquisition times, and small form factors.
This library communicates with the uBlox receivers using the UBX protocol and the UBX-NAV-PVT packet, which is available on uBlox 7 and 8 series receivers. Hardware serial is used for receiving the data packets.
This library uses the hardware serial for Teensy devices.
Simply clone or download and extract the zipped library into your Arduino/libraries folder.
Setup your uBlox receiver to output the UBX-NAV-PVT packet. Additional setup options include the desired GPS update frequency, the serial baud rate, and the expected dynamical environment. Setup of uBlox receivers can be accomplished using the uBlox u-center software.
UBLOX(uint8_t bus) A UBLOX object should be declared, specifying the hardware serial port the uBlox GPS receiver is connected to. For example, the following code declares a UBLOX object called gps located on the Teensy hardware serial port 3:
UBLOX gps(3);struct gpsData UBX-NAV-PVT packet data is made available via the gpsData structure, defined below. Please note that some of the values have been scaled from the raw UBX-NAV-PVT packet to provide the data in more conventional units.
struct gpsData {
unsigned long iTOW; ///< [ms], GPS time of the navigation epoch
unsigned short utcYear; ///< [year], Year (UTC)
unsigned char utcMonth; ///< [month], Month, range 1..12 (UTC)
unsigned char utcDay; ///< [day], Day of month, range 1..31 (UTC)
unsigned char utcHour; ///< [hour], Hour of day, range 0..23 (UTC)
unsigned char utcMin; ///< [min], Minute of hour, range 0..59 (UTC)
unsigned char utcSec; ///< [s], Seconds of minute, range 0..60 (UTC)
unsigned char valid; ///< [ND], Validity flags
unsigned long tAcc; ///< [ns], Time accuracy estimate (UTC)
long utcNano; ///< [ns], Fraction of second, range -1e9 .. 1e9 (UTC)
unsigned char fixType; ///< [ND], GNSSfix Type: 0: no fix, 1: dead reckoning only,
///< 2: 2D-fix, 3: 3D-fix, 4: GNSS + dead reckoning combined,
///< 5: time only fix
unsigned char flags; ///< [ND], Fix status flags
unsigned char flags2; ///< [ND], Additional flags
unsigned char numSV; ///< [ND], Number of satellites used in Nav Solution
double lon; ///< [deg], Longitude
double lat; ///< [deg], Latitude
double height; ///< [m], Height above ellipsoid
double hMSL; ///< [m], Height above mean sea level
double hAcc; ///< [m], Horizontal accuracy estimate
double vAcc; ///< [m], Vertical accuracy estimate
double velN; ///< [m/s], NED north velocity
double velE; ///< [m/s], NED east velocity
double velD; ///< [m/s], NED down velocity
double gSpeed; ///< [m/s], Ground Speed (2-D)
double heading; ///< [deg], Heading of motion (2-D)
double sAcc; ///< [m/s], Speed accuracy estimate
double headingAcc; ///< [deg], Heading accuracy estimate (both motion and vehicle)
double pDOP; ///< [ND], Position DOP
double headVeh; ///< [deg], Heading of vehicle (2-D)
};A new variable of the gpsData structure type should be created. For example, uBloxData is being created of the gpsData structure type.
gpsData uBloxData;void begin(int baud) This should be called in your setup function. It sets the baud rate and initializes the serial communication between the Teensy and uBlox GPS receiver. The specified baud rate should match the baud rate setup in the GPS receiver configuration. For example, the following code begins serial communication at a baud rate of 115200, which is the baud rate that the GPS receiver is using to transmit data:
gps.begin(115200);*bool read(gpsData gpsData_ptr) *read(gpsData gpsData_ptr) reads data from the uBlox receiver and parses the UBX-NAV-PVT packet. When a complete packet is received with a valid checksum, *read(gpsData gpsData_ptr) returns true and the parsed UBX-NAV-PVT packet data is available from the gpsData structure. For example, placing the following code in the loop function will print the latitude, in degrees, to the screen at the GPS update frequency.
if( gps.read(&uBloxData) ){
Serial.println(uBloxData.lat,10);
}Please refer to the Teensy pinout diagrams for hardware serial port pin information. For development purposes, the uBlox NEO 7P receiver available from CSG Shop and the uBlox M8 receiver available from HobbyKing were used.
For the uBlox M8 receiver available from HobbyKing, taking the red wire as pin 1, the following is the GPS receiver pinout:
| Pin | Description |
|---|---|
| 1 | Not Connected |
| 2 | Not Connected |
| 3 | 5V |
| 4 | RX (connect to Teensy TX) |
| 5 | TX (connect to Teensy RX) |
| 6 | GND |