USB barcode scanner read in Python on Raspberry Pi Raspbian

barcode_scanner_raspbian.py

# Props to user brechmos for sharing the code here: https://www.raspberrypi.org/forums/viewtopic.php?t=55100

# Tested with the following barcode scanner
# macbook# ioreg -p IOUSB 
# <snip>
#   | +-o WIT 122-UFS V2.03@14200000  <class AppleUSBDevice, id 0x10000c3c4, registered, matched, active, busy 0 (6 ms), retain 14>

#        WIT 122-UFS V2.03:
#          Product ID: 0x1010
#          Vendor ID: 0x05fe  (CHIC TECHNOLOGY CORP)
#          Version: 0.01
#          Speed: Up to 12 Mb/sec
#          Manufacturer: WIT Electron Company
#          Location ID: 0x14200000 / 4
#          Current Available (mA): 500
#          Current Required (mA): 500
#          Extra Operating Current (mA): 0

import sys

hid = { 4: 'a', 5: 'b', 6: 'c', 7: 'd', 8: 'e', 9: 'f', 10: 'g', 11: 'h', 12: 'i', 13: 'j', 14: 'k', 15: 'l', 16: 'm', 17: 'n', 18: 'o', 19: 'p', 20: 'q', 21: 'r', 22: 's', 23: 't', 24: 'u', 25: 'v', 26: 'w', 27: 'x', 28: 'y', 29: 'z', 30: '1', 31: '2', 32: '3', 33: '4', 34: '5', 35: '6', 36: '7', 37: '8', 38: '9', 39: '0', 44: ' ', 45: '-', 46: '=', 47: '[', 48: ']', 49: '\\', 51: ';' , 52: '\'', 53: '~', 54: ',', 55: '.', 56: '/'  }

hid2 = { 4: 'A', 5: 'B', 6: 'C', 7: 'D', 8: 'E', 9: 'F', 10: 'G', 11: 'H', 12: 'I', 13: 'J', 14: 'K', 15: 'L', 16: 'M', 17: 'N', 18: 'O', 19: 'P', 20: 'Q', 21: 'R', 22: 'S', 23: 'T', 24: 'U', 25: 'V', 26: 'W', 27: 'X', 28: 'Y', 29: 'Z', 30: '!', 31: '@', 32: '#', 33: '$', 34: '%', 35: '^', 36: '&', 37: '*', 38: '(', 39: ')', 44: ' ', 45: '_', 46: '+', 47: '{', 48: '}', 49: '|', 51: ':' , 52: '"', 53: '~', 54: '<', 55: '>', 56: '?'  }

fp = open('/dev/hidraw0', 'rb')


ss = ""
shift = False

done = False

while not done:
    ## Get the character from the HID
    buffer = fp.read(8)
    for c in buffer:
        if ord(c) > 0:
            ##  40 is carriage return which signifies
            ##  we are done looking for characters
            if int(ord(c)) == 40:
                done = True
                break;
            ##  If we are shifted then we have to 
            ##  use the hid2 characters.
            if shift: 
                ## If it is a '2' then it is the shift key
                if int(ord(c)) == 2 :
                    shift = True
                ## if not a 2 then lookup the mapping
                else:
                    ss += hid2[ int(ord(c)) ]
                    shift = False
            ##  If we are not shifted then use
            ##  the hid characters
            else:
                ## If it is a '2' then it is the shift key
                if int(ord(c)) == 2 :
                    shift = True
                ## if not a 2 then lookup the mapping
                else:
                    ss += hid[ int(ord(c)) ]
    print ss

hi,

I'm trying this on my raspberry pi. But I get an error 13 permission denied.

What I'm I doing wrong? Or what should I do to make it work?

Thanks

A permission issue doesn't sound like an issue with the code. Check if your user has permission to execute (sudo and chmod?)

I know it does not have anything to do with the code.
But how can I change the permissions on my raspberry pi?

@romeoGG run it as sudo

try executing below command in terminal:

sudo python Filename.py

Replace python with python3 if using Python 3 or above version.
Filename.py with your filename

I know it does not have anything to do with the code.
But how can I change the permissions on my raspberry pi?

first know the your hid device using below command:
ls -l /dev/hidraw*

than type following to change permission
sudo 777 /dev/hidraw*

replace * with your device number, like /dev/hidraw0

sudo chown $USER: /dev/hidraw0
This command will assign your user as the owner of the device. However it will be reverted once the device is rebooted.
This is supposing the device is /dev/hidraw0

• @romeoGG