I need a serial device expert!

[Caesars_10th]

Great thank you!

I have been reading up threading and the way I understand it, it is basically expanding your code from vertical to horizontal (running it in parallel). So if you had 5 workers, instead of each waiting for the one before it to be done before it can do its task, they can all do them at the same time. Here is a script from a video I watched:

import threading
import time


def talker(n, name):
    print('{} is sleeping\n'.format(name))
    time.sleep(n)
    print('{} has woken up!\n'.format(name))


start = time.time()

threads_list = []

for k in range(5):
    t = threading.Thread(target=talker, name='thread{}'.format(k),args=(5, 'thread{}'.format(k)))
    threads_list.append(t)
    t.start()


for t in threads_list:
    t.join()

end = time.time()

print('time taken: {}'.format(end-start))

With out threading this task would take 25 seconds. With threading, each worker does the same job at the same time. So the code only runs for 5 seconds:

Output:
thread0 is sleeping

thread1 is sleeping

thread2 is sleeping

thread3 is sleeping

thread4 is sleeping

thread0 has woken up!

thread2 has woken up!

thread3 has woken up!

thread4 has woken up!

thread1 has woken up!


time taken: 5.001632213592529

But how does this work with ser.readline Larz60+. How do I define a function to read the line and write it to a file?

Can I have workers perform different tasks?

Here's what I have tried:

import threading
import time
import datetime
import serial


ser = serial.Serial()
ser.port = 'COM2'
ser.baudrate = 460800
ser.timeout = 0.02
ser.bytesize = 8
ser.stopbits = 1

ser.open()

f = open('thread.txt', 'w')


def reader():
    line = ser.readline()
    time = datetime.datetime.now()
    f.write(str(time) + '    ' + str(line.replace(b'\r\n', b'').decode('utf-8')) + '\n')


while 1:
    start = time.time()

    threads_list = []

    for k in range(5):
        t = threading.Thread(target=reader)
        threads_list.append(t)
        t.start()

    for t in threads_list:
        t.join()

    end = time.time()

    print('time taken: {}'.format(end-start))


ser.close()

and the result:

Output:
2018-12-13 17:11:43.397547    
2018-12-13 17:11:43.397547    
2018-12-13 17:11:43.397547    
2018-12-13 17:11:43.397547    
2018-12-13 17:11:43.397547    
2018-12-13 17:11:43.418060    
2018-12-13 17:11:43.418060    
2018-12-13 17:11:43.418060    
2018-12-13 17:11:43.418060    
2018-12-13 17:11:43.418060    
2018-12-13 17:11:43.438575    
2018-12-13 17:11:43.438575    
2018-12-13 17:11:43.438575    
2018-12-13 17:11:43.438575
...   

It's not even reading the line from the port.