等待 TCP 连接时 LED 闪烁

Question

I want to blink LED on my Raspberry Pi TCP server when it waits for a connection to be established. After the transmission is opened, LED should stay on.

At this point my server looks like this:

connectioStatus = False
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.bind((host, port))
s.listen()
While True: 
    try:
        led_connection_indicator(connectioStatus)
        clientSocket, address = s.accept()
        connectioStatus = True
        while True:
        measure and send data
    except ConnectionResetError:
        handle error
        connectioStatus = False

and led_connection_indicator fucntion looks like this:

def led_indicator(status):
if status is True:
    GPIO.output(Led, GPIO.HIGH)
else:
    while status is False:
        GPIO.output(Led, GPIO.HIGH)
        sleep(1)
        GPIO.output(Led, GPIO.LOW)
        sleep(1)
        if connectionStatus is True: break

Of course, this is not working at all, the program is stuck in while loop. At first I thought that placing GPIO.HIGH and GPIO.LOW in the main While server loop will solve this but the program stops at s. Accept ().

Is this job for threads? I tried to use signals, but no luck

I wrote a simple TCP client in Qt for server. What is weird for me that after I connect from the client to the server, socket status in Qt, returns "QAbstractSocket:: ConnectedState" but no data is received.

Answer 1

socket.accept is blocking. You probably want to use select.select() which allows you to specify a timeout.