Pyserial设置缓冲区大小失败

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问题描述

使用set_buffer_size()设置缓冲区大小后，buffer size仍为默认的4096

import time
import serial
ser = serial.Serial(baudrate=9600, timeout=0.5)
ser.port = 'COM1'
ser.set_buffer_size(rx_size=8192)
ser.open()
while True:
    if input('Wait:') == 'q':
        break
    else:
        print('Buffer:', ser.inWaiting())
    time.sleep(1)
ser.close()

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原因分析

set_buffer_size()需要在串口打开后才能调用

"""\
Recommend a buffer size to the driver (device driver can ignore this
value). Must be called after the port is opened.
"""

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解决方案

先打开串口，再设置buffer size

ser = serial.Serial(baudrate=9600, timeout=0.5)
ser.port = 'COM1'
ser.open()
ser.set_buffer_size(rx_size=8192)

或者改为

ser = serial.Serial(port='COM1', baudrate=9600, timeout=0.5)
ser.set_buffer_size(rx_size=8192)

buffer size设置成功