sha016 / adafruit_circuitpython_gps

GPS parsing module for CircuitPython. Meant to parse NMEA data from serial GPS modules.

Introduction

GPS parsing module. Can send commands to, and parse simple NMEA data sentences from serial and I2C GPS modules to read latitude, longitude, and more.

Dependencies

This driver depends on:

• Adafruit CircuitPython

Please ensure all dependencies are available on the CircuitPython filesystem. This is easily achieved by downloading the Adafruit library and driver bundle.

Installing from PyPI

On supported GNU/Linux systems like the Raspberry Pi, you can install the driver locally from PyPI. To install for current user:

pip3 install adafruit-circuitpython-gps

To install system-wide (this may be required in some cases):

sudo pip3 install adafruit-circuitpython-gps

To install in a virtual environment in your current project:

mkdir project-name && cd project-name
python3 -m venv .env
source .env/bin/activate
pip3 install adafruit-circuitpython-gps

Usage Example

See examples/gps_simpletest.py for a demonstration of parsing and printing GPS location.

Important: Feather boards and many other circuitpython boards will round to two decimal places like this:

>>> float('1234.5678')
1234.57

This isn't ideal for GPS data as this lowers the accuracy from 0.1m to 11m.

This can be fixed by using string formatting when the GPS data is output.

An implementation of this can be found in examples/gps_simpletest.py

import time
import board
import busio

import adafruit_gps

RX = board.RX
TX = board.TX

uart = busio.UART(TX, RX, baudrate=9600, timeout=30)

gps = adafruit_gps.GPS(uart, debug=False)

gps.send_command(b'PMTK314,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0')

gps.send_command(b'PMTK220,1000')

last_print = time.monotonic()
while True:

    gps.update()

    current = time.monotonic()
    if current - last_print >= 1.0:
        last_print = current
        if not gps.has_fix:
            print('Waiting for fix...')
            continue
        print('=' * 40)  # Print a separator line.
        print('Latitude: {0:.6f} degrees'.format(gps.latitude))
        print('Longitude: {0:.6f} degrees'.format(gps.longitude))

These two lines are the lines that actually solve the issue:

print('Latitude: {0:.6f} degrees'.format(gps.latitude))
print('Longitude: {0:.6f} degrees'.format(gps.longitude))

Note: Sending multiple PMTK314 packets with gps.send_command() will not work unless there is a substantial amount of time in-between each time gps.send_command() is called. A time.sleep() of 1 second or more should fix this.

Documentation

API documentation for this library can be found on Read the Docs.

Contributing

Contributions are welcome! Please read our Code of Conduct before contributing to help this project stay welcoming.

Documentation

For information on building library documentation, please check out this guide.