所以我正在使用 GPS 模块、Python 和 MySQL 数据库制作一个应用程序。
所以我编写了一些代码，尝试从 GPS 捕获数据并将其存储在数据库中。我正在使用一个名为“pynmea2”的插件来解析一些数据（经度和纬度）。然而，我需要更多的数据，所以，我已经尝试了很多不同的事情，但我的程序一直崩溃。有人可以帮我解决这个问题吗？
大多数时候我从串行连接获取所有数据，但我希望能够从中剥离数据。我得到的例子：
[b'$GPGGA,093512.000,,,,,0,3,,,M,,M,,*47\r\n', b'$GPGLL,,,,,093512.000,V,N*76\r\n', b'$GPGSA,A,1,,,,,,,,,,,,,,,*1E\r\n', b'$GPGSV,3,1,11,15,72,214,,24,52,276,,13,48,141,,17,31,093,29*70\r\n', b'$GPGSV,3,2,11,18,28,292,,28,27,049,25,19,24,120,24,12,23,211,13*7E\r\n', b'$GPGSV,3
嗯，从中提取数据并不是那么简单，但是使用 pynmea2 库（唯一我允许使用的库）效果很好。
所以，我现在需要速度、纬度和经度，但速度现在困扰着我。它给出了
ValueError: could not convert string to float: "22*49\\r\\n'"
这是我当前正在使用的代码；
from model.GPSParser import GPSParser
from model.DB import DB
import serial
import time
import datetime
import pynmea2
#########################################
# This is the main code to setup the
# serial connection with the GPS module.
# it needs to be OR runt as root OR as
# pi with all the root rights.
#########################################
port = "/dev/ttyAMA0"
ser = serial.Serial(port, 9600, timeout=0)
#########################################
# These are all the global variables
# to be used. All defined and set to
# zero or their standard 'Null' value.
#########################################
lat = 0.0
lon = 0.0
cur_speed = 0.0
while True:
try:
# Get the data from the serial monitor.
data = str(ser.readlines()).lstrip("b'")[:-3]
# print(data)
#########################################
# Find the speed, to check if we're
# standing still or not. Save it in a
# @var speed
#########################################
if data.find('$GPVTG') != -1:
cur_speed = data.split(",")[7]
#########################################
# Get the Latitude and Longitude
#########################################
if data.find('$GPGGA') != -1:
print(data)
# Check whether the data strings are empty or not.
if GPSParser.parseLatitude(data) != "" and GPSParser.parseLongitude(data) != "":
lat = GPSParser.parseLatitude(data)
lon = GPSParser.parseLongitude(data)
# Debug printing
# print("Latitude: " + GPSParser.parseLatitude(data))
# print("Longitude: " + GPSParser.parseLongitude(data))
# print("Speed: " + cur_speed)
#########################################
# Insert the coordinates into the database
# Be sure to check of we are really driving
# So when the speed is higher then 5 km/u
# Store everything into the database.
#########################################
if float(cur_speed) > 5.0:
db = DB()
db.insertCoordinates(lat, lon, datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S"))
# Wait a bit to not overload the Serial port
time.sleep(0.5)
############################################################
# The error handling
############################################################
except serial.serialutil.SerialException:
ser.close()
port = "/dev/ttyAMA0"
ser = serial.Serial(port, 9600, timeout=0)
continue
except pynmea2.ParseError:
# print("Error on parsing object, continuing...")
continue
except BlockingIOError:
# print("Blocking I/O error, continuing...")
continue
except TypeError:
# print("Type error, continuing...")
continue
except IndexError:
# print("To catch an error...")
continue
except KeyboardInterrupt:
print("\nProgram stopped.")
exit()
所以从模型导入并没有做太多的事情，只有数据库连接和“gps解析器”只是解析一串数据然后返回它的pynmea。
所以我想要的是这样的：
它每秒获取一次脉冲的所有数据， 然后它会将其全部分割成以
$GPVTGGGA希望大家能够理解我并帮助我。
不确定这是否能解决您的问题，但 pynmea2 有速度属性，在 talker.py中定义。
import pynmea2
for i, line in enumerate(open('/tmp/nmea.txt').readlines()):
# parsing via pynmea
msg = pynmea2.parse(line.strip())
if msg.sentence_type == 'VTG':
print ('parsing line %s with pynmea:' % i, float(msg.spd_over_grnd_kmph))
# parsing via manually
if line.startswith('$GPVTG'):
cur_speed = line.split(",")[7]
print ('parsing line %s manually:' % i, float(cur_speed))
退货：
parsing line 1 with pynmea: 91.626
parsing line 1 manually: 91.626
parsing line 10 with pynmea: 90.842
parsing line 10 manually: 90.842
parsing line 19 with pynmea: 89.676
parsing line 19 manually: 89.676
我正在开发一个类似的程序，其中我从 GLL NMEA 句子收集数据。我使用了 try/ except 结构来丢弃不完整的数据，因此您永远不会有空的或损坏的 NMEA 句子。希望它能有所帮助：
# Libraries
import pynmea2
import serial
import io
# --------------------------------------------------------------------------------------------------------------------------------------------------- #
# Variables
lat_Rover1 = []
lat_Rover2 = []
lon_Rover1 = []
lon_Rover2 = []
# --------------------------------------------------------------------------------------------------------------------------------------------------- #
# Defining serial port to a variable
# ROVER 1
serial_port_Rover1 = 'COM3'
ser_Rover1 = serial.Serial(serial_port_Rover1, timeout=3)
# ROVER 2
serial_port_Rover2 = 'COM4'
ser_Rover2 = serial.Serial(serial_port_Rover2, timeout=3)
sio_Rover1 = io.TextIOWrapper(io.BufferedRWPair(ser_Rover1, ser_Rover1))
sio_Rover2 = io.TextIOWrapper(io.BufferedRWPair(ser_Rover2, ser_Rover2))
# --------------------------------------------------------------------------------------------------------------------------------------------------- #
while True:
# Reading NMEA data from Rovers
line_Rover1 = sio_Rover1.readline()
line_Rover2 = sio_Rover2.readline()
try:
msg_Rover1 = pynmea2.parse(line_Rover1, check=False)
msg_Rover2 = pynmea2.parse(line_Rover2, check=False)
except (pynmea2.ChecksumError, pynmea2.ParseError) as e:
print("Error parsing data: " + repr(line_Rover1))
print("Error parsing data: " + repr(line_Rover2))
# --------------------------------------------------------------------------------------------------------------------------------------------------- #
# Appending data to latitude and longitude list values
if msg_Rover1.sentence_type == 'GLL':
with open("NMEAOutputs_Rover1.txt", "a") as outputs:
# Getting only
# lat and lon as GLL
lat_Rover1.append(msg_Rover1.latitude)
lon_Rover1.append(msg_Rover1.longitude)
print(msg_Rover1.latitude,";",msg_Rover1.longitude,";", msg_Rover1.timestamp, file=outputs)
if msg_Rover2.sentence_type == 'GLL':
with open("NMEAOutputs_Rover2.txt", "a") as outputs:
# Getting only lat and lon as GLL
lat_Rover2.append(msg_Rover2.lat)
lon_Rover2.append(msg_Rover2.lon)
print(msg_Rover2.latitude,";",msg_Rover2.longitude,";", msg_Rover2.timestamp, file=outputs)
要获取速度，您可以使用 VTG NMEA 语句，其中地面速度以节为单位显示。要解析此数据，您可以使用：
# Filter for only GPS satellites
if msg_Rover1.talker == 'GP':
# Filter for only VTG NMEA Sentences
if msg_Rover1.sentence_type == 'VTG':
print(msg_Rover1.data[4])
我知道你说过你想将行分成几块，然后从逗号到逗号读取数据。但这是一个简单的方法。
在此示例中，我将纬度、经度和时间戳值存储在 txt 文件中，但您可以对它们执行任何操作。