I’m trying to connect elm327 Bluetooth with my raspberry pi and use the obd lib in python code to get car speed.

I’ve bind the device as below:
sudo rfcomm bind /dev/rfcomm0 xx:xx:xx:xx:xx:xx

Result of that when writing sudo rfcomm:
rfcomm0: xx:xx:xx:xx:xx:xx channel 1 clean

Now my python script:

import obd
import time

def connect_to_obd():
    connection = None
    while connection is None or not connection.is_connected():
        try:
            connection = obd.OBD("/dev/rfcomm0")
        except :
            print("Failed to connect to OBD-II adapter. Retrying in 5 seconds...")
            time.sleep(5)
    return connection

def get_vehicle_speed(connection):
    if connection.is_connected():
        cmd = obd.commands.SPEED  # select an OBD command (sensor)
        response = connection.query(cmd)  # send the command, and parse the response
        if response.value:
            return response.value.to("km/h").magnitude
    return 0

connection = connect_to_obd()
vehicle_speed = get_vehicle_speed(connection)
print(f"Vehicle Speed: {vehicle_speed} km/h")

Error MSG when ruining my code:

serial.serialutil.SerialException: device reports readiness to read but returned no data (device disconnected or multiple access on port?)

I did make sure that no other process is using the /dev/rfcomm0 port

Please any solution?

After connecting the ELM327 using Bluetooth and downloading all required lbs I expected my code run without errors and shows the car speed, which is did not.