Afternoon all,
I have a webpage that is being used to write NFC tags. When I submit the form on the page PHP sends the variables to the python script. This script (write.py) checks that the read.py script is killed and processes the write request. This part works fine.
The issue I have is when I recall the read.py, it contains a loop which is preventing the web page from refreshing once the write is complete. I have tried calling the read.py from inside the PHP script and at the end of the write.py and the same thing happens. I have also tried adding a & to the end of the read.py command.
Could someone please have a look at what I have so far and let me know what I am doing wrong and how I would go about fixing it please.
Cheers,
Blinky
HTML/PHP
<?php
session_start();
if( !empty( $_POST ) )
{
echo "Write to card using python";
$company = $_POST[ 'company' ];
$name = $_POST[ 'name' ];
$email = $_POST[ 'email' ];
$cmd = "sudo python write.py '$company' '$name' '$email' &";
$resp = shell_exec( $cmd );
if( strpos( $resp, 'written' ) !== false )
{
header("Location: http://192.168.1.176/index.php");
}
unset( $_POST );
}
?>
<form action="<?php echo $_SERVER["PHP_SELF"]; ?>" method="post">
<input type="text" name="name" id="name">
<input type="text" name="email" id="email">
<select name="company" id="company">
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
</select>
<input type="submit">
</form>
read.py
#!/usr/bin/env python
# -*- coding: utf8 -*-
import RPi.GPIO as GPIO
import MFRC522
import signal
import MySQLdb
import os
from datetime import datetime
os.system("sudo kill $(ps aux | grep 'write.py' | awk '{print $2}')")
db = MySQLdb.connect(host="", user="", passwd="", db="")
cursor = db.cursor()
continue_reading = True
# Capture SIGINT for cleanup when the script is aborted
def end_read(signal,frame):
global continue_reading
print "Ctrl+C captured, ending read."
continue_reading = False
GPIO.cleanup()
# Hook the SIGINT
signal.signal(signal.SIGINT, end_read)
# Create an object of the class MFRC522
MIFAREReader = MFRC522.MFRC522()
# Welcome message
print "Welcome to the MFRC522 data read example"
print "Press Ctrl-C to stop."
# This loop keeps checking for chips. If one is near it will get the UID and authenticate
while continue_reading:
# Scan for cards
(status,TagType) = MIFAREReader.MFRC522_Request(MIFAREReader.PICC_REQIDL)
# If a card is found
if status == MIFAREReader.MI_OK:
print "Card detected"
# Get the UID of the card
(status,uid) = MIFAREReader.MFRC522_Anticoll()
# If we have the UID, continue
if status == MIFAREReader.MI_OK:
uid_str = str(uid[0])+"."+str(uid[1])+"."+str(uid[2])+"."+str(uid[3])
# Print UID
#print "Card read UID: "+str(uid[0])+","+str(uid[1])+","+str(uid[2])+","+str(uid[3])
#print "\n".join(str(uid))
# This is the default key for authentication
key = [0xFF,0xFF,0xFF,0xFF,0xFF,0xFF]
# Select the scanned tag
MIFAREReader.MFRC522_SelectTag(uid)
# Authenticate
status = MIFAREReader.MFRC522_Auth(MIFAREReader.PICC_AUTHENT1A, 8, key, uid)
# Check if authenticated
if status == MIFAREReader.MI_OK:
print "Inserting data"
data = MIFAREReader.MFRC522_Read(8)
try:
date_time = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
query = "INSERT INTO %s (tag_uid, company, date_time, card_data) VALUES ('%s', '%s', '%s', '%s')"%('attendance_reader',uid_str,1,str(date_time),data)
cursor.execute(query)
db.commit()
print "Data committed"
except (MySQLdb.Error, MySQLdb.Warning) as e:
print(e)
print "Error: the database is being rolled back"
db.rollback()
MIFAREReader.MFRC522_StopCrypto1()
else:
print "Authentication error"
write.py
#!/usr/bin/env python
# -*- coding: utf8 -*-
import RPi.GPIO as GPIO
import MFRC522
import signal
import sys
import binascii
import os
import time
from random import randint
os.system("sudo kill $(ps aux | grep 'read.py' | awk '{print $2}')")
company = sys.argv[1]
name = sys.argv[2]
email = sys.argv[3]
ident_code = [int(company)]
for x in range(0,15):
ident_code.append(randint(001, 255))
print ident_code
continue_reading = True
# Capture SIGINT for cleanup when the script is aborted
def end_read(signal,frame):
global continue_reading
print "Ctrl+C captured, ending read."
continue_reading = False
GPIO.cleanup()
# Hook the SIGINT
signal.signal(signal.SIGINT, end_read)
# Create an object of the class MFRC522
MIFAREReader = MFRC522.MFRC522()
# This loop keeps checking for chips. If one is near it will get the UID and authenticate
while continue_reading:
# Scan for cards
(status,TagType) = MIFAREReader.MFRC522_Request(MIFAREReader.PICC_REQIDL)
# If a card is found
if status == MIFAREReader.MI_OK:
print "Card detected"
# Get the UID of the card
(status,uid) = MIFAREReader.MFRC522_Anticoll()
# If we have the UID, continue
if status == MIFAREReader.MI_OK:
# This is the default key for authentication
key = [0xFF,0xFF,0xFF,0xFF,0xFF,0xFF]
# Select the scanned tag
MIFAREReader.MFRC522_SelectTag(uid)
# Authenticate
status = MIFAREReader.MFRC522_Auth(MIFAREReader.PICC_AUTHENT1A, 8, key, uid)
#print "\n"
# Check if authenticated
if status == MIFAREReader.MI_OK:
#print "Sector 8 will now be filled with 0xFF:"
# Write the data
MIFAREReader.MFRC522_Write(8, ident_code)
# Stop
MIFAREReader.MFRC522_StopCrypto1()
#time.sleep(5)
continue_reading = False
os.system( "sudo python read.py" )
# os.system( "sudo python read.py &" )
# os.system( "sudo kill $(ps aux | grep 'write.py' | awk '{print $2}')" )
# Make sure to stop reading for cards
else:
print "Authentication error"
