# Simple GPS module demonstration. # Will wait for a fix and print a message every second with the current location # and other details. import time import board import busio import adafruit_gps # Create a serial connection for the GPS connection using default speed and # a slightly higher timeout (GPS modules typically update once a second). # These are the defaults you should use for the GPS FeatherWing. # For other boards set RX = GPS module TX, and TX = GPS module RX pins. uart = busio.UART(board.TX, board.RX, baudrate=9600, timeout=10) # for a computer, use the pyserial library for uart access # import serial # uart = serial.Serial("/dev/ttyUSB0", baudrate=9600, timeout=10) # If using I2C, we'll create an I2C interface to talk to using default pins # i2c = board.I2C() # Create a GPS module instance. gps = adafruit_gps.GPS(uart, debug=False) # Use UART/pyserial # gps = adafruit_gps.GPS_GtopI2C(i2c, debug=False) # Use I2C interface # Initialize the GPS module by changing what data it sends and at what rate. # These are NMEA extensions for PMTK_314_SET_NMEA_OUTPUT and # PMTK_220_SET_NMEA_UPDATERATE but you can send anything from here to adjust # the GPS module behavior: # https://cdn-shop.adafruit.com/datasheets/PMTK_A11.pdf # Turn on the basic GGA and RMC info (what you typically want) gps.send_command(b"PMTK314,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0") # Turn on just minimum info (RMC only, location): # gps.send_command(b'PMTK314,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0') # Turn off everything: # gps.send_command(b'PMTK314,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0') # Tuen on everything (not all of it is parsed!) # gps.send_command(b'PMTK314,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0') # Set update rate to once a second (1hz) which is what you typically want. gps.send_command(b"PMTK220,1000") # Or decrease to once every two seconds by doubling the millisecond value. # Be sure to also increase your UART timeout above! # gps.send_command(b'PMTK220,2000') # You can also speed up the rate, but don't go too fast or else you can lose # data during parsing. This would be twice a second (2hz, 500ms delay): # gps.send_command(b'PMTK220,500') # Main loop runs forever printing the location, etc. every second. last_print = time.monotonic() while True: # Make sure to call gps.update() every loop iteration and at least twice # as fast as data comes from the GPS unit (usually every second). # This returns a bool that's true if it parsed new data (you can ignore it # though if you don't care and instead look at the has_fix property). gps.update() # Every second print out current location details if there's a fix. current = time.monotonic() if current - last_print >= 1.0: last_print = current if not gps.has_fix: # Try again if we don't have a fix yet. print("Waiting for fix...") continue # We have a fix! (gps.has_fix is true) # Print out details about the fix like location, date, etc. print("=" * 40) # Print a separator line. print( "Fix timestamp: {}/{}/{} {:02}:{:02}:{:02}".format( gps.timestamp_utc.tm_mon, # Grab parts of the time from the gps.timestamp_utc.tm_mday, # struct_time object that holds gps.timestamp_utc.tm_year, # the fix time. Note you might gps.timestamp_utc.tm_hour, # not get all data like year, day, gps.timestamp_utc.tm_min, # month! gps.timestamp_utc.tm_sec, ) ) print("Latitude: {0:.6f} degrees".format(gps.latitude)) print("Longitude: {0:.6f} degrees".format(gps.longitude)) print("Fix quality: {}".format(gps.fix_quality)) # Some attributes beyond latitude, longitude and timestamp are optional # and might not be present. Check if they're None before trying to use! if gps.satellites is not None: print("# satellites: {}".format(gps.satellites)) if gps.altitude_m is not None: print("Altitude: {} meters".format(gps.altitude_m)) if gps.speed_knots is not None: print("Speed: {} knots".format(gps.speed_knots)) if gps.track_angle_deg is not None: print("Track angle: {} degrees".format(gps.track_angle_deg)) if gps.horizontal_dilution is not None: print("Horizontal dilution: {}".format(gps.horizontal_dilution)) if gps.height_geoid is not None: print("Height geo ID: {} meters".format(gps.height_geoid))