我正在尝试使用MPU-6000加速度计和Raspberry Pi 3 B在挡风玻璃中记录振动数据。我对Python相当陌生，所以请多包涵。
经过一些迭代，我编写了Python 2脚本，该脚本应该对传感器读取和csv写入使用多处理。 该计划将定义两个过程，其中一个过程侦听并捕获加速度计数据，而另一个过程将数据写入CSV文件。我正在使用事件来启动两个过程：传感器捕获的事件是通过按钮中断给出的，而csv写的事件是从传感器捕获过程给出的（当列表达到某个值时）。列表的内容放在队列中，应该由CSV写入过程读取。到目前为止，队列在到达时会放入一个新列表中，然后应该附加到CSV文件中。如果可以选择直接从队列中添加CSV文件，请告诉我。
截至目前，与我希望执行的操作相比，似乎CSV事件设置为随机间隔。最初，我的内部列表限制是2460个条目，并且出于故障排除的目的已将其减少。例如，对于listen_sens_data中的内部accel_list限制为10，则每次我输入listen_sens_data时都会设置CSV事件，因为打印的“ CSV事件状态”是肯定的。数据似乎已放入队列中，但是将数据放入队列后直接调用q.get（）会显示缺少第一个数据点。同样，仅从队列中读取下四个数据点，列表的大小无关紧要。初步测试证明，通过调用csv_event，csv_write_list函数最初在第一次迭代中处于活动状态，但是除了来自其他函数的伪数据之外，没有其他数据被写入CSV文件。 有人看到我犯过任何明显的错误吗？并可能有一种更结构化的方式来执行此特定操作吗？
下面是脚本，下面是运行脚本的图片。
#!/usr/bin/python
import smbus
import math
import csv
import time
import sys
import datetime
import RPi.GPIO as GPIO
import os
from multiprocessing import Queue, Process, Event
# Register addresses
power_mgmt_1 = 0x6b
power_mgmt_2 = 0x6c
samplerate_divider = 0x19
accel_config = 0x1C
I2C_mast_ctrl = 0x24
Mot_Det_Ctrl = 0x69
INT_Enable = 0x38
#Enable analog GPIO pins for LED control and push button ctrl
GPIO.setmode(GPIO.BCM)
GPIO.setup(23, GPIO.IN, pull_up_down=GPIO.PUD_UP)
GPIO.setup(24, GPIO.IN, pull_up_down=GPIO.PUD_UP)
GPIO.setwarnings(False)
GPIO.setup(17, GPIO.OUT)
GPIO.setup(27, GPIO.OUT)
GPIO.output(17, GPIO.HIGH)
GPIO.output(27, GPIO.HIGH)
time.sleep(2)
GPIO.output(17, GPIO.LOW)
GPIO.output(27, GPIO.LOW)
accel_status = 0
green_led_status=False
#Interrupt for starting measurement
def start_meas_callback(channel):
global accel_status
accel_status = 1
accel_event.set()
print "Starting accelerometer measurements, logging to CSV file"
GPIO.output(17, GPIO.HIGH)
GPIO.output(27, GPIO.HIGH)
return accel_event
GPIO.add_event_detect(23, GPIO.FALLING, callback=start_meas_callback, bouncetime=300)
#Interrupt for stopping measurement
def stop_meas_callback(channel):
global accel_status
global green_led_status
accel_status = 0
accel_event.clear()
print "Accelerometer measurements stopped, written to CSV file"
#Closing csv file
csv_close()
GPIO.output(17, GPIO.HIGH)
GPIO.output(27, GPIO.HIGH)
time.sleep(1)
GPIO.output(27, GPIO.LOW)
time.sleep(2)
GPIO.output(17, GPIO.LOW)
return accel_event
GPIO.add_event_detect(24, GPIO.FALLING, callback=stop_meas_callback, bouncetime=300)
#Read functions
def read_byte(reg):
return bus.read_byte_data(address, reg)
def read_word(reg):
h = bus.read_byte_data(address, reg)
l = bus.read_byte_data(address, reg+1)
value = (h <<8)+l
return value
def read_word_2c(reg):
val = read_word(reg)
if (val >= 0x8000):
return -((65535 - val) + 1)
else:
return val
csvwriter = None
filename_total =0
filepath_merge = 0
#Opening / creating a CSV file
def csv_open():
global filename_total
global filepath_merge
filename_time_raw = datetime.datetime.now()
filename_time=filename_time_raw.strftime('%y-%m-%d--%H:%M:%S')
filename_total='accel-data-'+filename_time+'.csv'
filepath = os.path.dirname(os.path.abspath(filename_total))
print "Absolute filepath"
print filepath
filepath_merge = os.path.join(filepath, filename_total)
print "Merged filepath"
print filepath_merge
csvfile = open(filepath_merge, 'a')
global csvwriter
csvwriter = csv.writer(csvfile)
#Closing csv file
def csv_close():
global csvwriter
global filepath_merge
with open(filepath_merge, 'a') as csvfile:
csvwriter.writerow(['File close',' file close',' file close',' file close'])
#Writing content to CSV file
def csv_write(timedelta, accelerometerx, accelerometery, accelerometerz):
global csvwriter
csvwriter.writerow([timedelta, accelerometerx, accelerometery, accelerometerz])
#Write entire content from a list or Queue to CSV file
#def csv_write_list(accel_list_inp, csv_event):
def csv_write_list():
global csvwriter
#global accel_list
#global green_led_status
item = []
print "waiting for CSV event"
csv_event.wait()
if csv_event.is_set():
print " CSV_WRITE event captured!"
print csv_event
#for i in iter(q.get()):
#item.append(q.get())
#print "Q value is \n"
#print q.get()
# print i
print " \n Printing item list if for loop is passed: \n"
print item
csvwriter.writerows(item)
print "\n CSV file written? \n"
#GPIO.output(27, GPIO.LOW)
#GPIO.output(27, green_led_status)
#green_led_status = not green_led_status
#accel_list[:]=[]
item [:] = []
csv_event.clear()
print "State of CSV event now: \n"
print csv_event
#Extend list while sampling data
def list_ext(timedelta_lst, accelerometerx_lst, accelerometery_lst, accelerometerz_lst):
accel_list.extend([[timedelta_lst, accelerometerx_lst, accelerometery_lst, accelerometerz_lst]])
#print (accel_list)
#Function to listen for sensor data. Will be used for multiprocess purpose
def listen_sens_data(accel_event):
#global accel_status
#global accel_list
#global list_length
green_led_status = True
accel_list=[]
list_length = 2460
while True:
accel_event.wait()
if accel_event.is_set():
data_interrupt_read = bus.read_byte_data(address, 0x3A)
if data_interrupt_read == 1:
GPIO.output(27, GPIO.LOW)
GPIO.output(27, green_led_status)
green_led_status = not green_led_status
meas_time = datetime.datetime.now()
accelerometer_xout = read_word(0x3b)
accelerometer_yout = read_word(0x3d)
accelerometer_zout = read_word(0x3f)
#list_ext(meas_time, accelerometer_xout, accelerometer_yout, accelerometer_zout)
accel_list.extend([[meas_time, accelerometer_xout, accelerometer_yout, accelerometer_zout]])
print "State of CSV_event: \n"
print csv_event
if len(accel_list) == 10:
print "accel_list being written \n"
print accel_list
map(q.put, accel_list)
#csv_event.set()
for i in iter(q.get()):
print "Content of Q: \n"
print q.get()
accel_list[:]=[]
print "state of CSV_event after set!!!!: \n"
print csv_event
print "acccel list empty?"
print accel_list
#return csv_event
#GPIO.output(27, GPIO.LOW)
#GPIO.output(27, green_led_status)
#green_led_status = not green_led_status
#break
#csv_write_list(accel_list)
#I2C settings
bus = smbus.SMBus(1) # bus = smbus.SMBus(1)
address = 0x69 # via i2cdetect
# Power management settings
bus.write_byte_data(address, power_mgmt_1, 0)
bus.write_byte_data(address, power_mgmt_2, 0x00)
#Configure sample-rate divider
#bus.write_byte_data(address, samplerate_divider, 0x0C)
bus.write_byte_data(address, samplerate_divider, 0xFF)
#Configure data ready interrupt:
bus.write_byte_data(address,INT_Enable, 0x01)
#Opening csv file and getting ready for writing
csv_open()
csv_write('Time', 'X_Axis', 'Y_Axis', 'Z_Axis')
print
print "Accelerometer"
print "---------------------"
print "This is multi-processing"
print "Write data to list, then to CSV"
print "Please push button 1 to start logging accelerometer data "
print "Push button 2 to stop logging accelerometer data"
if __name__ == '__main__':
q = Queue(maxsize=0)
accel_event = Event()
csv_event = Event()
csv_event.clear()
p1=Process(target=listen_sens_data, args=(accel_event,) )
#p2=Process(target=csv_write_list, args=(q, csv_event,))
p2=Process(target=csv_write_list,)
p1.start()
p2.start()
#q.close()
#q2.close()
#q.join_thread()
#p1.join()
#p2.join()
从终端窗口输出：
pi@raspberrypi:~ $ sudo python accel_pb_multipc.py
Absolute filepath
/home/pi
Merged filepath
/home/pi/accel-data-19-01-09--17:48:04.csv
Accelerometer
---------------------
This is multi-processing
Write data to list, then to CSV
Please push button 1 to start logging accelerometer data
Push button 2 to stop logging accelerometer data
waiting for CSV event
Starting accelerometer measurements, logging to CSV file
State of CSV_event:
<multiprocessing.synchronize.Event object at 0x761c6810>
State of CSV_event:
<multiprocessing.synchronize.Event object at 0x761c6810>
State of CSV_event:
<multiprocessing.synchronize.Event object at 0x761c6810>
State of CSV_event:
<multiprocessing.synchronize.Event object at 0x761c6810>
State of CSV_event:
<multiprocessing.synchronize.Event object at 0x761c6810>
State of CSV_event:
<multiprocessing.synchronize.Event object at 0x761c6810>
State of CSV_event:
<multiprocessing.synchronize.Event object at 0x761c6810>
State of CSV_event:
<multiprocessing.synchronize.Event object at 0x761c6810>
State of CSV_event:
<multiprocessing.synchronize.Event object at 0x761c6810>
State of CSV_event:
<multiprocessing.synchronize.Event object at 0x761c6810>
accel_list being written
[[datetime.datetime(2019, 1, 9, 17, 48, 5, 594852), 52, 228, 47700], [datetime.datetime(2019, 1, 9, 17, 48, 5, 607713), 40, 208, 47760], [datetime.datetime(2019, 1, 9, 17, 48, 5, 639358), 96, 408, 47808], [datetime.datetime(2019, 1, 9, 17, 48, 5, 671228), 65532, 184, 47712], [datetime.datetime(2019, 1, 9, 17, 48, 5, 702824), 16, 232, 47700], [datetime.datetime(2019, 1, 9, 17, 48, 5, 734651), 124, 308, 47644], [datetime.datetime(2019, 1, 9, 17, 48, 5, 766272), 168, 136, 47588], [datetime.datetime(2019, 1, 9, 17, 48, 5, 798043), 324, 308, 47808], [datetime.datetime(2019, 1, 9, 17, 48, 5, 829792), 176, 212, 47644], [datetime.datetime(2019, 1, 9, 17, 48, 5, 861571), 65480, 160, 47848]]
Content of Q:
[datetime.datetime(2019, 1, 9, 17, 48, 5, 607713), 40, 208, 47760]
Content of Q:
[datetime.datetime(2019, 1, 9, 17, 48, 5, 639358), 96, 408, 47808]
Content of Q:
[datetime.datetime(2019, 1, 9, 17, 48, 5, 671228), 65532, 184, 47712]
Content of Q:
[datetime.datetime(2019, 1, 9, 17, 48, 5, 702824), 16, 232, 47700]
state of CSV_event after set!!!!:
<multiprocessing.synchronize.Event object at 0x761c6810>
acccel list empty?
[]
State of CSV_event:
<multiprocessing.synchronize.Event object at 0x761c6810>
State of CSV_event:
<multiprocessing.synchronize.Event object at 0x761c6810>
State of CSV_event:
<multiprocessing.synchronize.Event object at 0x761c6810>
State of CSV_event:
<multiprocessing.synchronize.Event object at 0x761c6810>
State of CSV_event:
<multiprocessing.synchronize.Event object at 0x761c6810>
State of CSV_event:
<multiprocessing.synchronize.Event object at 0x761c6810>
State of CSV_event:
<multiprocessing.synchronize.Event object at 0x761c6810>
State of CSV_event:
<multiprocessing.synchronize.Event object at 0x761c6810>
State of CSV_event:
<multiprocessing.synchronize.Event object at 0x761c6810>
State of CSV_event:
<multiprocessing.synchronize.Event object at 0x761c6810>
accel_list being written
[[datetime.datetime(2019, 1, 9, 17, 48, 5, 893203), 88, 184, 47736], [datetime.datetime(2019, 1, 9, 17, 48, 5, 924978), 65516, 188, 47852], [datetime.datetime(2019, 1, 9, 17, 48, 5, 956636), 92, 220, 47728], [datetime.datetime(2019, 1, 9, 17, 48, 5, 988486), 132, 124, 47728], [datetime.datetime(2019, 1, 9, 17, 48, 6, 20205), 156, 172, 47944], [datetime.datetime(2019, 1, 9, 17, 48, 6, 51899), 92, 260, 47724], [datetime.datetime(2019, 1, 9, 17, 48, 6, 83681), 72, 320, 47840], [datetime.datetime(2019, 1, 9, 17, 48, 6, 115352), 108, 216, 47736], [datetime.datetime(2019, 1, 9, 17, 48, 6, 147018), 44, 228, 47708], [datetime.datetime(2019, 1, 9, 17, 48, 6, 178720), 36, 140, 47696]]
Content of Q:
[datetime.datetime(2019, 1, 9, 17, 48, 5, 766272), 168, 136, 47588]
Content of Q:
[datetime.datetime(2019, 1, 9, 17, 48, 5, 798043), 324, 308, 47808]
Content of Q:
[datetime.datetime(2019, 1, 9, 17, 48, 5, 829792), 176, 212, 47644]
Content of Q:
[datetime.datetime(2019, 1, 9, 17, 48, 5, 861571), 65480, 160, 47848]
state of CSV_event after set!!!!:
<multiprocessing.synchronize.Event object at 0x761c6810>
acccel list empty?
[]