Python connection with a Device through serial port - python

I need help with a python code to connect with a Router or a Switch via serial port. I use pycharm from a Windows terminal.
This is what I tried:
import keyboard
ser = serial.Serial(port="COM1", baudrate=9600, bytesize=8, timeout=2, stopbits=serial.STOPBITS_ONE)
while True:
ser.write('You got connected\r\n'.encode('Ascii'))
receive = ser.readline()
print(receive.decode('Ascii'))
if keyboard.is_pressed('q'):
print('User need to quit the app.')
break
ser.close()
Tried and I got errors.

What error do you get ?
This would be very helpful if you could copy/paste your errors in here.

Related

Attempting to use pyserial between applications, yet I get terminal

(update)
So I found some documentation on this link
https://elinux.org/RPi_Serial_Connection#Connections_and_signal_levels
If you scroll down you will find a section "S/W: Preventing Linux from using the serial port" It says "By default Linux will grab the serial port and use it as a terminal."
So it appears that this is a thing, however, the instructions it gives is for a Raspberry Pi, and it calls for you to use raspi-config. It doesn't give anything for regular linux use.
Using python I'm attempting to communicate between my laptop and an Up-Board. I'm connecting the Up-board by using an FTDI cable, connected to the serial connection on the board.
(OP)
I've done something similar before with C++ on a different board. The code I'm using I pulled from this site, http://www.varesano.net/blog/fabio/serial%20rs232%20connections%20python
import time
import serial
ser = serial.Serial(
port='/dev/ttyUSB0',
baudrate=115200,
parity=serial.PARITY_NONE,
stopbits=serial.STOPBITS_ONE,
bytesize=serial.EIGHTBITS
)
print ser.isOpen()
input=1
while 1 :
input = raw_input(">> ")
print "Check"
try:
if input == 'exit':
ser.close()
exit()
else:
ser.write(input + '\r\n')
out = ''
time.sleep(1)
while ser.inWaiting() > 0:
out += ser.read(1)
if out != '':
print ">>" + out
except:
ser.close()
break
I'm doing something similar on the Up-board. The only difference is that it waits for a message, then returns the message back to my laptop. Just a loop back between the Upboard and my laptop.
Here's where it gets interest.
I'm having two seperate issues.
1) I'll attempt to send a word, ie "test" and it will only send "e", "tst" doesn't get sent
2) The other issue is, it sends message, and I get a return for a password. So I reset the software and attempt to connect again, this time I send the username as the first message. I get back a reply for password, then I send the password, and now I have terminal access to the Upboard. While, all I really want is to connect to the application on the other end.
Does anyone have any suggestions on what is going on?
So I found the resolution, it appears that the system was configured in grub to connect to terminal on the same port address.
if you go to /etc/default/grub you will find a line
GRUB_CMDLINE_LINUX="console=ttyS0, 115200n8"
I ended up commenting that line, and I now can connect without it giving me console control.

Python raspberry pi serial sim868 Login incorrect

why sometime it is working?
I try to call at command.
How can I fix it?
import serial
import time
port = serial.Serial("/dev/ttyS0", baudrate=115200, timeout=1)
port.write('AT'+'\r\n')
print port.read(10)
time.sleep(.1)
output
Perhaps the serial port is kept open and you need to close it before accessing it again?
Try putting the delay before the read:
time.sleep(.1)
print port.read(10)

How to read data from serial port? Python

Hi please bear my basic question as I am new to python.
I am trying to read data from serial port. Basically serial port is a USB port converted to serial port virtually. I am using arduino.
First i tried this code:
while(True):
ser=serial.Serial('COM6',9600)
bytoread=ser.inWaiting()
val=ser.read(bytoread)
But it gave me error.
Permission Error(13,Access is denied, none 5)
But when i changed my code to
while(True):
ser=serial.Serial()
ser.baudrate=19600
ser.port='COM6'
ser
ser.open()
bytoread=ser.inWaiting()
val=ser.read(bytoread)
Permission error did not come but program is always busy connecting the port. I waited for many minutes but it never moved forward. What I am doing wrong here?
you can do something like :
import serial
ser = serial.Serial('COM6', 9600, timeout=None)
while True:
data = ser.readline()
you can't put ser = serial.Serial('COM5', 9600, timeout=None) in your while loop because it will permanently (re)create the connection...

Receiving data from com port by pyserial

I can't receive data from com port by pyserial! I have compiled program that send data and receive answer from controller correctly! I used comport monitor program to spy request and answer from controller:correct send and answer
But when I send the same request i get nothing((my request without answer
My Python prog:
#!/usr/bin/env python
import sys, os
import serial, time
from serial import *
ser = serial.Serial(
port='COM7',
baudrate=4800,
bytesize=5,#18,
parity='N',
stopbits=1,
timeout=5,
xonxoff=0,#
rtscts=0,#
writeTimeout = 1#1
myz= '\x10\x02\x00\x00\x01\x4e\xf0\x04\x01\xff\x10\x17\x02\x4e\xf0\x04\x02\xff\x10\x17\x10\x03\xff'
while True:
ser.write(myz) #send data
ser.readline()
I was trying different speeds(4800,9600) and got nothing(((
Can anybody tell me where I get mistayke?
You'll not receive your own message on the com port you write it to. Either connect the other side of the cable to a different port, or communicate with a device that will answer you.

Error in working with pyserial module of python

import time
import serial
# configure the serial connections (the parameters differs on the device you are connecting to)
ser = serial.Serial(
port='/dev/ttyS0',
#port='/dev/ttyACM0',
baudrate=115200,
parity=serial.PARITY_ODD,
#stopbits=serial.STOPBITS_TWO,
#bytesize=serial.SEVENBITS
)
ser.isOpen() # returns true
time.sleep(1);
ser.write("some_command \n")
ser.close()
I have a embedded board. It has a serial port which is connected to my computer. I am running above script to access this serial port and run some board specific commands.
My problem
I open my serial port (using minicom in linux) separately and then run above script, It works. If I don't open serial port separately, Script doesn't work.
try
ser.write("some_command \n".encode())
alternatively try
ser.write(bytes(b"some_command \n"))

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