Printing QR codes with Thermal Printer

[russg]

I'm wondering if any of you guys could help me?

I'm fairly new to Raspberry Pi's and Python, but I'm trying to get mine to print QR codes off from a thermal printer to eventually print off Bitcoin private and public keys.

Does anyone have any source code I could use to print QR codes and a bit of a layman's guide to getting it to print off. I've managed to get the printer to work, so I guess it's just adapting the code to print off what I want now?

[DougieLawson]

https://learn.adafruit.com/mini-thermal ... r/overview

sudo apt-get install qrencode imagemagick
qrencode -o qr.png -t png "Hello World"
will generate a PNG image that you can convert to BMP with ImageMagick
convert qr.png qr.bmp

[russg]

Thanks, but I'm not wanting to just print a PNG image, I'm wanting to generate a QR code from a bitcoin public and private key.

I have been following this guys blog for instructions, but i'm stuck with this error message:

Traceback (most recent last):
File “printkeys.py”, line 62, in
Piper.genAndPrintKeys(rememberkeys, rememberKeys, numCopies, “”)
File “/home/pi/Piper/piper.py”, line 226, in genAndPrintKeys
btckeys.genKeys()
File “/home/pi/Piper/genkeys.py”, line 32, in genKeys
process = Popen([“./vanitygen”, “-q”, “-t”,”l”,”-s”, “/dev/random”,”-X”, addrVersion, addrPrefix ], stdout=PIPE)
File “/usr/lib/python2.7/subprocess.py”, line 679, in __init__
errread, errwrite)
File “/usr/lib/python2.7/subprocess.py”, line 1259, in _execute_child
raise child_exception
OSError: [Errno 13] Permission denied