ESP-Now 数据吞吐量记录在 GPS 坐标上

Question

我正在使用两块 ESP32 板进行 ESP-Now 通信，其中一个 ESP 正在发送数据包，而另一个正在接收它们，同时将这些数据与 GPS 一起记录，以测量特定坐标处的吞吐量，以便我在移动时获得吞吐率和发送方和接收方之间的变化率。

ESP32 接收器和 GPS 模块连接到 Rpi，Rpi 正在运行从串行 com 端口读取数据、解析数据并将其写入文件的脚本。

import serial
import time
import pandas as pd

# Receiver
esp_com = '/dev/ttyUSB1'
esp_baud = 115200
ser = serial.Serial(port=esp_com, baudrate=esp_baud, timeout=0.1)

# GPS
gps_com = '/dev/ttyUSB0'
gps_baud = 4800
sergps = serial.Serial(port=gps_com, baudrate=gps_baud, timeout=0.1)

# title of the file to write data in
title = 'ESP-NOW LoRa'

# time step at which data is logged
timestep = 1

# create lists
XCV = []

# initial dropped/received packets data
drp = 0
rcv = 0
counter = 0

waiting_for_recv = False

# outputs empty data table
df = pd.DataFrame()

# outputs time in seconds since the timer started
then = time.time()
then1 = time.time()

# clear ESP buffers
ser.flushInput()
ser.flushOutput()

# initial data
RECEIVED = 0
RECEIVED = []
LAT = []
LON = []
T = []
t = 0
gpsdata = ''

# loop
while True:
    try:
        xcv = ser.readline().decode()  # decodes string
        if xcv != '':
            xcv = xcv.split("\r\n")
            for x in xcv:
                if x != '':
                    print(x)
                    XCV.append(x)
                    if 'RECV' in x:
                        RECEIVED = int(x[4:])  # sliced first 4 characters

        while True:
            cvb = sergps.readline()
            if cvb != b'':
                if 'GNGGA' in cvb.decode():
                    gpsdata = cvb.decode()
            else:
                break

        now = time.time()

        if now > then+timestep:
            print(now)
            df.at[counter, 'timestamp'] = now
            df.at[counter, 'received'] = RECEIVED
            drp = 0
            rcv = 0

            RECEIVED = 0
            then = now

            counter += 1

            vbn = gpsdata.split(',')
            if('GNGGA' in vbn[0]) & (vbn[2] != "") & (len(vbn) >= 5):
                print('GPS has a fix')
                tt = vbn[1]
                lat = vbn[2]
                lon = vbn[4]
                lat = int(lat[0:2])+float(lat[2:])/60
                lon = int(lon[0:3])+float(lon[3:])/60
                LAT.append(lat)
                LON.append(lon)
                T.append(t)
                t += 1
                print('LAT: {}, LON: {}'.format(lat, lon))

            else:
                print('GPS does not have a fix')
                LAT.append(0)
                LON.append(0)

            # write data to file every 30 seconds
            if now > then1+30:
                then1 = now
                # print GPS dataframe to columns
                df['lat'] = LAT
                df['lon'] = LON
                df.to_excel(title+'.xlsx')  # writes data to excel file

    except Exception as e:
        print(e)

我遇到了一个问题，一旦 GPS 修复，并开始发送带有坐标的完整 NMEA 消息，接收/丢弃的数据包数据丢失，整个脚本挂起。我可以在我的变量中看到 GPS NMEA 数据被正确解析，当 GPS 没有修复时，一切正常，但是一旦它开始发送带有坐标的完整 NMEA 消息，脚本就会中断。

我自己也搞不清楚为什么，我认为代码本身需要优化。

Answer 1

我看到已经有一段时间了，但我偶然发现了这篇文章。

所以我看到一个问题：

while True:
    cvb = sergps.readline()
    if cvb != b'':
         if 'GNGGA' in cvb.decode():
             gpsdata = cvb.decode()
    else:
        break

在这里，当任何数据来自 GPS 模块时，您将陷入循环。得到

gpsdata

.

后，你可能也想打破

另一件事在这里你有布尔值所以使用

and

（逻辑）而不是

&

（按位）：

vbn = gpsdata.split(',')
    if('GNGGA' in vbn[0]) & (vbn[2] != "") & (len(vbn) >= 5):
        print('GPS has a fix')

在这里阅读更多内容：'and'（布尔值）与'&'（按位）