The Thermal Printer is working!

Finally, the thermal printer is working!

The size of thermal paper is 57 * 50. I followed guide here, DevTerm/Code/thermal_printer at main · clockworkpi/DevTerm · GitHub

It’s time to figure out how to print sth except test word.



The driver seems work perfectly. I tried print sth by LibreOffice Writer and it works!



Wow, really nice! A graceful device.


Does it make a loud noise when it is running?


echo -e “Hello DevTerm\n\n\n\n\n\n” > /tmp/DEVTERM_PRINTER_IN


Yes it does, more than an thermal printer from a POS system


Are you able to print something really long? For example: can you easily setup a page size so that you can print a meter of text?

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Get it procedurally print out Pi. Ha! Topical!
Unlike say the old Gameboy printer, the paper should be fairly cheap to buy, if you’re using POS receipts.
I’m more worried about excessive use potentially wearing out the printer unit. But bring thermal based, it sounds like it should be as bullet proof as a dot matrix ribbon printer.

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I think you may run out of paper before the head die, I mean printer in POS are heavily used and they don’t seems to die easily, the only moving part is the paper and the rolls to move the paper, the head does not move on this type of printer (that’s also why they tend to be more reliable in general)


I have a few thermal printers for TRS-80 pocket computers that are still working from the '80s

I tried to print a PDF file via qpdfview (Ctrl+P) and via lp -d devterm_printer test.pdf.
In both cases the printer starts to rattle but instantly stops. I can print any text directly from terminal. Is there another way to print a PDF file? Images are working fine too.

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Whell I made it working with this function:

printpdf() {
 #try to fit pdf
 lp -d devterm_printer -o fit-to-page -o media=A8 -o scaling=200 "$1"

I placed the function in my ~/.profile and us it like printpdf file.pdf


Is there any detailed manual on how to use the printer? Especially how to print documents and images in editing software?
Any best practice advices?

and here is how to use lp to print png file

export LPDEST=devterm_printer
lp some.png

You can always send a pull request also :slight_smile: if you find mistakes or improvements.


And also reporting such issues on github is probably a better place than lost somewhere on this forum.

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I have a situation where pigments from the paper seem to stick to the head, I dont know if its from the paper, I will try to get another one but it will take time. This one I got locally and I have 10 rolls :sweat_smile:

Its driving me nuts, I will order some rolls from Amazon and try again.

@Petrakis, easy way to test the paper is to take a heat gun (or hairdryer on high) and run it back and forth over the paper. The nose of the gun should be about 1/2 inch from the paper. The paper will slowly get blue/grey then black. You will see any defects in the paper roll that way.

Also it looks like there are some shiny streaks on the paper. Do those run the length of the roll? Or just after the paper goes over the print head?

If the streaks are only showing after the paper is run then that could indicate debris on or before the print head. Although your second picture looks clean.

The shiny streaks is the debris on the head grinding on the paper and they vary their location. On the second picture if you follow the black line on the head you will see black dots, thats it, and thats what makes the shiny lines.

If I take a piece of paper and clean them they are gone for some time and they appear again wherever the debris got deposited on the head again.

You can clean the print head with 99% isopropyl alcohol on a cotton swab.

Turn the device off first; let it dry completely before powering back on.