树莓派，Python：如何通过 usb 串口发送大数据？

Question

I am trying to send a large amount of data from my Raspberry Pi 4 to my computer. I configured the Raspberry Pi as USB OTG Serial Gadget and the data is sent through the usb-c port to my computer.

Please take a look at the following code running on the Raspberry Pi. One MB of data is sent.

import serial

ser = serial.Serial( port='/dev/ttyGS0', baudrate=115200)

packet = bytearray()
for i in range(0, 1000000):
    packet.append(0x2f)

ser.write(packet)

This is the code I am running first on my computer.

import serial
import time

ser = serial.Serial(port='COM30', baudrate=115200)

sum = 0
while 1:
    bytesToRead = ser.inWaiting()
    if bytesToRead > 0:
        serial_line = ser.read(bytesToRead)
        sum += bytesToRead
        print(sum)
    time.sleep(0.01)

I would expect that the received data has always the same length as the sent data. But in this example the computer receives a data length of around 990.000 Bytes in most cases. Even if I run the code without the sleep function on my computer, there are sometimes missing bytes.

How can I make sure that the data is sent and received without data loss?

Answer 1

First, if you have enabled logins on the serial port, you need to disable them first otherwise the port will be inaccessible.

Second, stop getty@ttyGS0.service and disable it.

And then everything will work fine.