This is from Arz Fine Foods. Their logo is a tree. On this receipt, they’ve got a tree alright, but no-one expected an MS-DOS directory tree. I think, as we sort of say in Scotland, that someone made an arz of this …
(I’m not hating on Arz, btw. They have an epic selection of foods, including fresh Sukkari dates.)
This might be my last post on mini-printers, as I’ve found a driver that just works with CUPS on Raspberry Pi. It also works on Ubuntu on my laptop, and should work (though untried) on Mac OS. You’ll have to build it from source, but it’s not too hard.
The hard part is working out if your thermal printer will work or not. There are many out there, and they’re all slightly different. If they support the ESC/POS bitmap command GS v 0 on 58 mm wide paper, they should work. The ones I’ve tested are:
Catex POS5890U — USB, cheap, fast.
“701” control board panel printer — fairly generic, decent quality printer with serial input. A bit slow for daily use at 9600 baud.
Xiamen Embedded Printer DP-EH600 — as above.
The following should also work, but haven’t been tried:
Sparkfun thermal printer — which now appears to be identical to the Adafruit unit, and is referred to as the “A1 (or A2) micro panel printer” in the documentation.
Known not to work:
BTHT-V6 printer — which uses a completely different command set. (Roughly that of an Epson FX-80 for image commands, if you care.)
If you have a manual for your printer, check it to see if it prints bitmaps by sending a three byte header of 29 118 48 (or 1D 76 30 in hexadecimal). If you’re not sure, try it with a small test image, and be ready by the power switch …
This bit is much more graphical. You’ll need the system-config-printer package:
sudo apt install -y system-config-printer
Open up the printer settings window (Preferences → Print Settings):
Select the Add icon, and the New Printer window opens:
The POS5890U shows up as “Unknown” on my USB port, as Linux doesn’t know the name of this device from its USB ID.
Update (for the slightly desperate): In the land of “Things have changed!”, my Catex printer isn’t showing up at all. I had to resort to this in the Enter URI option:
parallel:/dev/usb/lp0 seems to work. Another option might be looking at the output of
which suggests that usb://Unknown/Printer might work too. (All of this might need to have been preceded by
sudo usermod -a -G lp pi
and a logout or reboot; I did say this was for the slightly desperate …)
If the above doesn’t apply, your printer might have an known ID, or show up as a serial port. Select the right one, and click Forward:
Here, I’m really pleased that the driver is for a Zijiang unit, as it’s conveniently at the end of the list. Click Forward …
No options here, so again, Forward …
I changed the name from the default ZJ-58 to the more unixly zj58. You don’t have to, but either way, Apply the changes.
And there it is, registered as a printer!
Most printers expect paper wider than 58 mm, but mini-printers can’t do that. To tell the system about paper sizes, right click on the printer’s icon, and change the printer settings:
A test page might print properly now, but you should probably go into Printer Options first:
You do want to set the media size to at least 58 × 210 mm. This is just the longest strip it will print in one ‘page’; if your print is shorter, it won’t waste extra paper. You can choose longer prints, but not wider. The default assume your local standard paper size which —be it A4, Letter, or whatever — will not be what you want here. Hit OK.
You could print the self test page, but it’s long and boring. If you’re fairly sure your printer will be supported, try this scaled PDF version of the Raspberry Pi Logo: raspberry-pi-logo. Printed and scanned, it came out like this:
Not the best rendition, but not bad for a $30 receipt printer. My test image came out like this (iffy scan, sorry):
I haven’t covered the intricacies of setting up serial port connections here; maybe another time. Also, there’s a short delay (maybe 10–20 s) between selecting Print and the printer coming to life. CUPS is pretty complex, and is doing things in the background while you wait.
(Seeing as I use their logo prominently up there, I should totes acknowledge that “Raspberry Pi is a trademark of the Raspberry Pi Foundation”. Also, I couldn’t have done all this without the support of Reed Zhao. Though Reed has moved on to bigger things and doesn’t sell printers any more, his help — not to mention the generous loan of a couple of printers — was very welcome.)
Scored this cheapo USB printer on eBay: “High-speed 58mm POS Dot Receipt Paper Thermal Printer USB”. It identifies itself as a CATEX Technolog [sic] POS5890U, with a USB vendor:product ID of b000:0410. After a bit of random fiddling, it shows up as /dev/usb/lp0 on a Raspberry Pi. After turning off CUPS (as it nabs the device, not even letting root near it), you can print images up to 384 dots (48 mm at 8 dots/mm) wide using the ESC-POS GS v 0 command. You can use my esc-pos-image.py script if you wish, and if you need a test image …
(The photo is of Marie Doro; proto-goth 1902 style.)
Over the last few weeks, I’ve been playing with a few small thermal printers. Meant as POS or information booth printers, they make a diverting project for the lo-fi printing enthusiast. While they all have common features — 58 mm/2¼” paper width, 8 pixel/mm resolution, 48 mm print width, serial connection — they all have their quirks. You may have seen these sold as the Adafruit Mini Thermal Receipt Printer or Sparkfun’s Thermal Printer, but there are many others. I’m going to write more on interfacing these directly to Raspberry Pi, Arduino, and (if I can navigate the documentation) a CUPS driver.
For now, I’m just leaving you a list of things I’ve found helpful for the DP-EH600 and 701 printers. Note that the similar-looking BTHT-v6 printer uses a completely different command set.
Replacement paper is sold as 2¼” × 30′. Staples have a box of 30 rolls for under $25 (item 279096, not on their website). Longer rolls don’t fit.
You’ll need a USB→TTL Serial adaptor, preferably one with DTR control. I use one from JY-MCU. In a pinch, you can use a simpler Debug / Console Cable for Raspberry Pi, but you risk serial overruns and dodgy results. Remember that RX on the adaptor goes to TX on the printer, and vice versa.
A good solid power supply is needed; these printers draw ~8 W when printing. Some printers only support 5 V (for which a 3 amp adaptor would be ideal), others 5-9 V. The higher voltage makes text printing faster. You can’t drive these directly from your Raspberry Pi/Arduino power supply.
Linux serial ports are set to some defaults which may have been historically useful, but now corrupt 8-bit data. A trick I picked up here is to first issue the command stty -F /dev/ttyUSB1 0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0
which clears all settings, then set the device up as you need it: stty -F /dev/ttyUSB1 speed 9600 raw cs8
(Most of these printers default to 9600 baud. Your device may be called something different to ttyUSB1.)
I’ve written a couple of Python driver stubs which take an image and produce the relevant binary output:
scruss / esc-pos-image.py – prints an image as a single command. May not work on the SparkFun printer. Does not work on the BTHT-v6.
scruss / esc-pos-image-star.py – prints the image in 24 pixel deep bands. Can sometimes cause visible gaps in the printout, but will work on almost all printers, except the BTHT-v6.
These Python libraries also work, as long as you address the printer properly (right device, right speed):
python-escpos – image support limited to 255 pixels high, for some reason.
Reed Zhao (of Tangram Software) lent me a couple of different printers for testing after I bought a different one from him. He’s put a lot of work into sourcing these printers direct from the manufacturers. Thanks, Reed! NB: Reed doesn’t sell printers any more. Try eBay.