thanks for your time.

Im getting some headhaches with a python script that takes the uID from RC522 tag reader then open a specific URL with the UID in a web browser..

It was working great on my RPI model B+ (Raspbian Wheezy) Now, i'been upgraded to a RPI 3 B+ (for a better performance) and the scripts read the uID but i can't get the browser open... i have been searching a lot of hours into google but no answer to my question.

Here is the output:

    Detected: 10
Card read UID: 23,96,179,17
Setting tag
Selecting UID [23, 96, 179, 17, 213]



Changing auth key and method to None
--user-data-dir --disable-quic --enable-tcp-fast-open --ppapi-flash-path=/usr/lib/chromium-browser/libpepflashplayer.so --ppapi-flash-args=enable_stagevideo_auto=0 --ppapi-flash-version=
[3535:3535:0806/065332.412397:ERROR:zygote_host_impl_linux.cc(89)] Running as root without --no-sandbox is not supported. See https://crbug.com/638180.
--user-data-dir --disable-quic --enable-tcp-fast-open --ppapi-flash-path=/usr/lib/chromium-browser/libpepflashplayer.so --ppapi-flash-args=enable_stagevideo_auto=0 --ppapi-flash-version=
[3557:3557:0806/065333.223510:ERROR:zygote_host_impl_linux.cc(89)] Running as root without --no-sandbox is not supported. See https://crbug.com/638180.
/usr/bin/xdg-open: 870: /usr/bin/xdg-open: firefox: not found
/usr/bin/xdg-open: 870: /usr/bin/xdg-open: iceweasel: not found
/usr/bin/xdg-open: 870: /usr/bin/xdg-open: seamonkey: not found
/usr/bin/xdg-open: 870: /usr/bin/xdg-open: mozilla: not found
No protocol specified
Unable to init server: Could not connect: Connection refused
Failed to parse arguments: Cannot open display: 
/usr/bin/xdg-open: 870: /usr/bin/xdg-open: konqueror: not found
/usr/bin/xdg-open: 870: /usr/bin/xdg-open: chromium: not found
--user-data-dir --disable-quic --enable-tcp-fast-open --ppapi-flash-path=/usr/lib/chromium-browser/libpepflashplayer.so --ppapi-flash-args=enable_stagevideo_auto=0 --ppapi-flash-version=
[3594:3594:0806/065334.420571:ERROR:zygote_host_impl_linux.cc(89)] Running as root without --no-sandbox is not supported. See https://crbug.com/638180.
/usr/bin/xdg-open: 870: /usr/bin/xdg-open: google-chrome: not found
/usr/bin/xdg-open: 870: /usr/bin/xdg-open: www-browser: not found
/usr/bin/xdg-open: 870: /usr/bin/xdg-open: links2: not found
/usr/bin/xdg-open: 870: /usr/bin/xdg-open: elinks: not found
/usr/bin/xdg-open: 870: /usr/bin/xdg-open: links: not found
/usr/bin/xdg-open: 870: /usr/bin/xdg-open: lynx: not found
/usr/bin/xdg-open: 870: /usr/bin/xdg-open: w3m: not found
xdg-open: no method available for opening 'http://localhost/verperfil/rfid.php?rfid=239617917'

and here is the code

import signal
import time
import sys
import webbrowser
from pirc522 import RFID
#chrome = chromium-browser()

run = True
rdr = RFID()
util = rdr.util()
util.debug = True

def end_read(signal,frame):
    global run
    print("\nCtrl+C captured, ending read.")
    run = False

signal.signal(signal.SIGINT, end_read)

while run:

    (error, data) = rdr.request()
    if not error:
        print("\nDetected: " + format(data, "02x"))

    (error, uid) = rdr.anticoll()
    if not error:
        print("Card read UID: "+str(uid[0])+","+str(uid[1])+","+str(uid[2])+","+str(uid[3]))

        print("Setting tag")

        #util.auth(rdr.auth_a, [0x12, 0x34, 0x56, 0x78, 0x96, 0x92])
        #util.auth(rdr.auth_b, [0x74, 0x00, 0x52, 0x35, 0x00, 0xFF])


i can't run chromium with root permissions

  • 1
    You don't seem to have any browsers installed. Aug 6, 2019 at 9:30
  • Yes, i have installed (with sudo apt-get) chromium-browser and midori.
    – obdb
    Aug 6, 2019 at 13:34

1 Answer 1


Well, i was "closed-in-to-just-one-posibility" -or not thinking clear- The MFRC522-Python lib "Read.py" cannot be executed without sudo AND the chromium-browser CANNOT BE EXECUTED as SUDO, so... Afters a lot of Coffee and hours i found that i can execute the Read.py as SUDO and inside of it, the web browser directly with another username

basicly i have modified my script and replace this


to this:

os.system('sudo -upi chromium-browser http://localhost/verperfil/rfid.php?rfid='+str(uid[0])+''+str(uid[1])+''+str(uid[2])+''+str(uid[3])+'')

Of course,

import os
import system

at the top+

and the browser just starts perfectly, one thing, is i dont know why the script get paused when browser is opened.. but this topic is ended :) THANKS TO ALL OF US

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