Add support for YT01 model

[williamd1k0]

I bought this model recently and ended up getting a little frustrated because the only way to use it was through a suspicious mobile app.
I will be very grateful if you can add support for this model. I can help you with any information, testing and maybe even coding.

Recommended app: (iBleem) https://play.google.com/store/apps/details?id=com.bleem.liugm

Thank you so much for working on this project.

[NaitLee]

I see it's yet another brand.
I'm gonna try another app, because it's a) by same vendor, b) looks cleaner ok, still that dirty, c) seems made for world I think it's also machine translated... "also"...
I don't think it's a fast process, since it's really different.

[NaitLee]

Hi, you may help me to find the Bluetooth "Characteristics" of YT01.
Use nRF Connect, open the printer, find it with "Scanner" and see what's inside.

(the original app has really bad UI logic)

[williamd1k0]

(the original app has really bad UI logic)

Yeah 😅, I've tried this "Fun Print" now and it's actually the same as iBleem with slight differences in the UI.

Some pics:

Use nRF Connect, open the printer, find it with "Scanner" and see what's inside.

Ok, I will try it out.

[williamd1k0]

Screenshots

Log 2022-05-04 02_47_13.txt

nRF Connect, 2022-05-04
YT01 (33:9F:3E:E3:1F:63)
V	02:45:45.750	Connecting to 33:9F:3E:E3:1F:63...
D	02:45:45.750	gatt = device.connectGatt(autoConnect = false, TRANSPORT_LE)
D	02:45:46.935	[Broadcast] Action received: android.bluetooth.device.action.ACL_CONNECTED
D	02:45:46.974	[Callback] Connection state changed with status: 0 and new state: CONNECTED (2)
I	02:45:46.975	Connected to 33:9F:3E:E3:1F:63
D	02:45:46.980	wait(1600ms)
V	02:45:48.582	Discovering services...
D	02:45:48.582	gatt.discoverServices()
D	02:45:48.617	[Callback] Services discovered with status: 0
I	02:45:48.617	Services discovered
V	02:45:48.669	Generic Access (0x1800)
- Device Name [R W] (0x2A00)
Unknown Service (0000ae30-0000-1000-8000-00805f9b34fb)
- Unknown Characteristic [WNR] (0000ae01-0000-1000-8000-00805f9b34fb)
- Unknown Characteristic [N] (0000ae02-0000-1000-8000-00805f9b34fb)
   Client Characteristic Configuration (0x2902)
- Unknown Characteristic [WNR] (0000ae03-0000-1000-8000-00805f9b34fb)
- Unknown Characteristic [N] (0000ae04-0000-1000-8000-00805f9b34fb)
   Client Characteristic Configuration (0x2902)
- Unknown Characteristic [I] (0000ae05-0000-1000-8000-00805f9b34fb)
   Client Characteristic Configuration (0x2902)
- Unknown Characteristic [R W] (0000ae10-0000-1000-8000-00805f9b34fb)
Unknown Service (0000ae3a-0000-1000-8000-00805f9b34fb)
- Unknown Characteristic [WNR] (0000ae3b-0000-1000-8000-00805f9b34fb)
- Unknown Characteristic [N] (0000ae3c-0000-1000-8000-00805f9b34fb)
   Client Characteristic Configuration (0x2902)
D	02:45:48.670	gatt.setCharacteristicNotification(0000ae02-0000-1000-8000-00805f9b34fb, true)
D	02:45:48.673	gatt.setCharacteristicNotification(0000ae04-0000-1000-8000-00805f9b34fb, true)
D	02:45:48.677	gatt.setCharacteristicNotification(0000ae05-0000-1000-8000-00805f9b34fb, true)
D	02:45:48.681	gatt.setCharacteristicNotification(0000ae3c-0000-1000-8000-00805f9b34fb, true)

[NaitLee]

Oh thank you, it's very detailed 😄
Next step for me is to trick the app to send data, dump it & analyze.
The tool is also nRF Connect.
And I feel these steps are universal and worth to make a tutorial later 🙃

The printer is completely different, maybe including communication "magic data".
Let me gather more...

[NaitLee]

Oh, wait, Services/Characteristics UUID needs to be full.
Long tap on each entry (and sub-entry) in connected YT01 "Client", on right-top there's copy button.
Put them in a text file, and be sure to label corresponding Properties (read, write, notify, etc)
It's a repeating process, but maybe worthwhile 😉

[NaitLee]

Some side notes:

• the original app is actually in JavaScript
• it also support many other models, of their own
• the real code is in assets (of apk). but obfuscated
• rough stat: more than 50 js files, each is around 100kib in average. after prettify there will be 10,000 lines per file
• that doesn't mean it's better than similar things: bad naming convention, pinyin variable names & english typos, poorly managed processing logic (aka Spaghetti Code, for example using if everywhere for different printer models)
• above is got with minified code. just think about how's their codebase.
• the communication "magic data" is buried in these obscure code. it will take some time to dig its logic out, but our traffic dumping technique may improve efficiency
• inside, the only thing I feel good about is i18n

In order to really support all YTXX I think we need more people, for sharing & testing.
But I have no ability to do them all by myself 😢

I will continue slowly.

EDIT: just now I see the "magic data" is likely to be the same (or very similar) as GBXX models.

[williamd1k0]

Oh, wait, Services/Characteristics UUID needs to be full. Long tap on each entry (and sub-entry) in connected YT01 "Client", on right-top there's copy button. Put them in a text file, and be sure to label corresponding Properties (read, write, notify, etc) It's a repeating process, but maybe worthwhile 😉

No problem, I'll do that as soon as possible! (I'm a bit busy right now)

[williamd1k0]

It's a repeating process, but maybe worthwhile

Thanks to KDE Connect I was able to share the text directly to my PC instead of copying/pasting everything manually 😅

Let me know if anything is still missing.

Generic Access:
  UUID: 0x1800
  PRIMARY SERVICE:
    Device Name:
      UUID: 0x2A00
      Properties: READ, WRITE
      Parsed value: YT01
      Raw value: (0x) 59-54-30-31, "YT01"

Unknown Service:
  UUID: 0000ae30-0000-1000-8000-00805f9b34fb
  PRIMARY SERVICE:
    Unknown Service:
      UUID: 0000ae01-0000-1000-8000-00805f9b34fb
      Properties: WRITE NO RESPONSE
    Unknown Service:
      UUID: 0000ae02-0000-1000-8000-00805f9b34fb
      Properties: NOTIFY
    Unknown Service:
      UUID: 0000ae03-0000-1000-8000-00805f9b34fb
      Properties: WRITE NO RESPONSE
    Unknown Service:
      UUID: 0000ae04-0000-1000-8000-00805f9b34fb
      Properties: NOTIFY
    Unknown Service:
      UUID: 0000ae05-0000-1000-8000-00805f9b34fb
      Properties: INDICATE
    Unknown Service:
      UUID: 0000ae10-0000-1000-8000-00805f9b34fb
      Properties: READ, WRITE
      Parsed value: (0x) 00-00-00-00
      Raw value: (0x) 00-00-00-00

Unknown Service:
  UUID: 0000ae3a-0000-1000-8000-00805f9b34fb
  PRIMARY SERVICE:
    Unknown Service:
      UUID: 0000ae3b-0000-1000-8000-00805f9b34fb
      Properties: WRITE NO RESPONSE
    Unknown Service:
      UUID: 0000ae3c-0000-1000-8000-00805f9b34fb
      Properties: NOTIFY

[NaitLee]

I see they are just very alike.
Please test if this brute way would work:

• Pick a release, or clone repo & install deps
• Open file printer_lib/models.py, inside add a model YT01 as the same as any other:

   Models = {
       'YT01': Model(384, False),
       'GB01': Model(384, False),
       # ...
   }

• Try to print...

Edit: I've made this change in newest commit. You can simply try it by cloning repo.

[williamd1k0]

It's working!!

[NaitLee]

Ah great 😄
So next times I should not overlook other models. They have big chance to be the same 😅
But who knows when I will meet a really different one...

Side note: this appearance (printer face) is the newest kind of my local Online store
Off-topic: our laptop is very similar

[williamd1k0]

Off-topic: our laptop is very similar

Hehe, mine is a Lenovo Ideapad S145.

So, I will close the issue now. Thanks again for working on this project, it's really helpful.
I will definitely help improve the app (UI, features, i18n etc) in the future, one thing I was looking forward to before buying the printer was this specific project: https://github.com/receiptline/receiptline (I really like to automate things through the command-line 😅).

[braintapper]

FWIW, I was able to get my cat printer model (MX05) to work using the YT01 settings.

[NaitLee]

So there are many "unknown but supported" models.
That may mean I should put a "Test other devices" feature, with existing settings :)