Re: Sending USB commands with Python

2012-08-30 Thread Tim Roberts
"Adam W." wrote: > >You are correct about the 2 being the number of bytes written. However when I >issue a read command I get: > ep.write('\x1BA') >4 ep.read(1) >usb.core.USBError: [Errno None] b'libusb0-dll:err [_usb_setup_async] invalid >endpoint 0x02\n' USB endponts only go in one

Re: Sending USB commands with Python

2012-08-30 Thread Cameron Simpson
On 30Aug2012 05:51, Adam W. wrote: | On Thursday, August 30, 2012 12:55:14 AM UTC-4, Dennis Lee Bieber wrote: | > How many bytes did it claim to send? | | 11, which is what I expected. But I changed the byte value to 16 | (because I was having trouble getting single digit hex values working |

Re: Sending USB commands with Python

2012-08-30 Thread Adam W.
On Thursday, August 30, 2012 12:55:14 AM UTC-4, Dennis Lee Bieber wrote: > > How many bytes did it claim to send? > 11, which is what I expected. But I changed the byte value to 16 (because I was having trouble getting single digit hex values working in the command) and sent this command:

Re: Sending USB commands with Python

2012-08-29 Thread Adam W.
On Wednesday, August 29, 2012 10:07:54 PM UTC-4, Dennis Lee Bieber wrote: > On Wed, 29 Aug 2012 16:45:10 -0700 (PDT), "Adam W." > > I'm a tad curious if using the notation > > > > b'\x1bA' > > > > without the .encode() would work. > > > > My concern is that you ma

Re: Sending USB commands with Python

2012-08-29 Thread MRAB
On 30/08/2012 00:45, Adam W. wrote: On Wednesday, August 29, 2012 6:56:16 PM UTC-4, Dennis Lee Bieber wrote: BUT you do give a possible clue. Is the OP using a 3.x Python where strings are Unicode -- in which case the above may need to be explicitly declared as a "byte string" rather

Re: Sending USB commands with Python

2012-08-29 Thread Adam W.
On Wednesday, August 29, 2012 6:56:16 PM UTC-4, Dennis Lee Bieber wrote: > > BUT you do give a possible clue. Is the OP using a 3.x Python where > > strings are Unicode -- in which case the above may need to be explicitly > > declared as a "byte string" rather than text (unicode) string. >

Re: Sending USB commands with Python

2012-08-29 Thread Cameron Simpson
On 30Aug2012 08:29, I wrote: | UTF-16? ISTR that Windows often uses big endian UTF-16 [...] Sorry, little-endian. Anyway... -- Cameron Simpson Ed Campbell's pointers for long trips: 3. Stop and take a break before you really need it. -- http://mail.python.org/mailman/listinfo/python-list

Re: Sending USB commands with Python

2012-08-29 Thread Cameron Simpson
On 29Aug2012 17:57, Dennis Lee Bieber wrote: | On Wed, 29 Aug 2012 14:21:30 -0700 (PDT), "Adam W." | declaimed the following in | gmane.comp.python.general: | > You are correct about the 2 being the number of bytes written. However when I issue a read command I get: | > | > >>> ep.write('\x1BA

Re: Sending USB commands with Python

2012-08-29 Thread Adam W.
On Wednesday, August 29, 2012 4:09:49 PM UTC-4, Dennis Lee Bieber wrote: > > Don't the commands require an character? "\x1BA" (or >"\x1B\x41") > > OTOH, if the is issued behind the scenes, I'm not sure which esc char it is asking for, I don't think libusb is providing its own,

Re: Sending USB commands with Python

2012-08-29 Thread Adam W.
On Wednesday, August 29, 2012 2:45:17 AM UTC-4, Tim Roberts wrote: > Which operating system are you using? If you are on Windows, then the > > operating system has already loaded a printer driver for this device. > > > The libusb or libusbx libraries can be used to talk to USB devices. There

Re: Sending USB commands with Python

2012-08-28 Thread Tim Roberts
"Adam W." wrote: > >So I'm trying to get as low level as I can with my Dymo label printer, >and this method described the PDF >http://sites.dymo.com/Documents/LW450_Series_Technical_Reference.pdf >seems to be it. > >I'm unfamiliar with dealing with the USB interface and would greatly >appreciat

Re: Sending USB commands with Python

2012-08-28 Thread hamilton
On 8/28/2012 11:04 PM, alex23 wrote: On Aug 29, 1:03 pm, hamilton wrote: The OP posted the link to the manual. If your not going to at least look it over, . Speaking for myself, I _don't_ go out of my way to read extra material But, you will give advice that has no value. Anything

Re: Sending USB commands with Python

2012-08-28 Thread alex23
On Aug 29, 1:03 pm, hamilton wrote: > The OP posted the link to the manual. > If your not going to at least look it over, . Speaking for myself, I _don't_ go out of my way to read extra material to help someone with a problem here. If it's worth mentioning, mention it in the question. --

Re: Sending USB commands with Python

2012-08-28 Thread hamilton
On 8/28/2012 8:54 PM, Dennis Lee Bieber wrote: 2) does the printer appear as a serial port by the OS? Or as a printer device? The OP posted the link to the manual. If your not going to at least look it over, . USB Printer Interface The LabelWriter 450 series printers al

Re: Sending USB commands with Python

2012-08-28 Thread Jorge Mazzonelli
Hi, I recommend the use of the module PyUSB in sourceforge: http://pyusb.sourceforge.net/ Also take a look to the tutorial : http://pyusb.sourceforge.net/docs/1.0/tutorial.html as far as I can remember, you'll need to first find the device based on the idvendor / idproduct (provided in the pdf).