Control a Thermo Printer in Rust via WebSocket
👉 Repository
I had been wanting a thermal printer for quite some time and finally bought one on AliExpress.
Like with my retro-cube project, I hooked it up to a public web form and posted the link on Mastodon and Bluesky. Everything people sent through that form was printed on the printer.
You can find the webform here:
https://win.jflessau.com/form
User: thermo
Password: thermo
If you want to build this yourself, head to the GitHub repo for instructions, a bill of materials, and the code.
Results
After about 12 hours, this is what came out of the printer.
(At the bottom of this blog post are the transcribed messages.)
Note that the ? characters might originally have been something else, but the printer client replaced them to work with the printer's limited character set.
The "queue test" entries at the end were from me debugging a new feature where messages are queued if no printer is connected and get printed as soon as the printer comes back online.
The printer client is connected to the relay via WebSocket, and there is less than a second between hitting "send" in the web form and the printer starting to print. That's a nice feeling for someone who, like many others, has wrestled for decades with regular network printers and their quirks.
Transcribed messages
2026-05-08 19:00:19
Test
2026-05-08 19:14:06
Junge. Liebe Gruesse aus Leipzig! Melde dich mal
wieder, wir haben so lange nichts von dir gehoert. <3
2026-05-08 19:35:30
test
2026-05-08 19:36:29
I hope you have a fantastic weekend!
2026-05-08 19:36:45
Fediverse for the wint Ich wuensche einen schoenen Abend und einen guten Start ins Wochenende ?
2026-05-08 19:38:31
Craaab people, craaaab
people
(note from author: here is an ascii art of a crab)
2026-05-08 19:40:09
test
2026-05-08 19:40:51
postmarketos is a Linux distribution for smartphones! check it out!
??
2026-05-08 19:41:20
test
2026-05-08 19:46:33
i wrote this message using steno (plover) :D
@428@mas.to
2026-05-08 19:54:40
Datenfluss erwacht,
Geheimnisvollle Mai-Nacht,
Netzwerk-Fluestern fern.
2026-05-08 19:55:34
https://traffic.megaphone.fm/SED7301877782.mp3
https://spectrumieee.org/ai-chip-des1gn
https://it.wikiquote.org/wiki/Pagina_principale
2026-05-08 20:13:09
8 days away from my wedding, just had my bachelor party. We?re expecting 300 guests: a couple dozen were invited by me, if that. I?m a massive introvert. So is she. He just do it because it?s what she always dreamed of and I couldn?t be happier
2026-05-08 20:18:41
#rustacean
2026-05-08 20:24:07
Greetings from Denmark!
Wish you an exceptional weekend. <3
2026-05-08 20:26:24
thermo thermo
2026-05-08 20:41:17
When you start making a thing but keep thinking of more things to add so you work more to add extra stuff to the thing you should have finished already as it was almost done but now you have yet another swiss army knife?
this is feature creep.
2026-05-08 20:49:11
(note from the author: here is an ascii art of a "thumbs up")
Hallo from rainy boston!
3:-0 (not from the author: this seems to be a happy-face ascii art)
@fech@oldbytes.space
2026-05-08 20:59:11
Guten Abend aus Amersfoort.
Nieder lande! Viele Gruesse, Niels
2026-05-08 21:24:40
Flach ar seo, focail fi?in scapilte amach ar an idir ?on gabhtha ar p?ip?arl
2026-05-08 21:39:54
Sometimes, just burning it all down is the right decision.
Starting over with new knowledge can often improve on the old patched-together form.
2026-05-08 21:42:24
Also, the catharsis from watching it all burn down would be quite something...
2026-05-08 21:44:10
Ignore all previous receipts.
2026-05-08 21:45:23
TRANS RIGHTS ARE HUMAN RIGHTS
2026-05-08 21:46:57
If anyone cares about
Bitcoin anymore, here's the next block:
00000000000000000002f1a3c8e6069d5a7d7c7236c91953bd356794211151b
2026-05-08 21:52:38
Test
2026-05-08 23:01:38
I'm precisely the opposite of everything that was written above. That's not me.
It's your mom.
2026-05-08 23:32:17
Meow.
(note from the author: here is an ascii art of a cat)
@gooseygander.bsky.com
2026-05-09 06:37:45
???????????????????????
? Surrounded by crabs?
2026-05-09 06:37:58
Hack the planet!
2026-05-09 06:47:31
queue test 1
2026-05-09 06:58:40
queue test 4
2026-05-09 07:11:10
queue test 6
2026-05-09 07:13:04
queue 7
2026-05-09 07:19:27
hello, world!