Dymo 550 Thermal Printer DRM Hacking

[js_12345678_55AA]

Meanwhile I created a new release (v1.1.1 on Github) which should fix the pass through problem introduced with v1.1.0.
=> https://github.com/free-dmo/free-dmo-stm32/releases/tag/v1.1.1

Next few days I should have some more time to check everything with my 550 Rev. K.

JS

[Axis-3790]

Rev I
550 Turbo QF4

I have tested v1.1.1 and it is showing improvement compared to the previous version. It will now detect official dymo branded labels w/ the bluepill. No flashing lights. It did not take the default 30336 label when I tried testing an after market roll.

[Bastelwastl]

@JS, thanks for the early x-mas present, works fine

@Axis-3790, did you try to flash another precompiled .bin from the v1.1.1 ZIP File?

[Axis-3790]

I did not use a precompiled. I have been compiling my own firmware via WSL everytime. I can use a precompiled firmware if that is the recommended method.

[lemonotype]

Hello everyone!

I signed up to:
1. Thank everyone involved for doing god's work and letting me use a machine I paid for as I see fit.
2. Report my experience / findings as I didn't see them outlined here exactly.

Here's how it went:
1. I bought the machine (5XL) mid-December off Amazon, flashed 1.1.1 on Bluepill and it immediately worked fine.
2. A day or two (and less than 10 labels) later it started showing up as empty on Dymo software.
3. The only way to get it to print was to send labels to print, get the empy error, then turn it off and on, it would print all labels then start flashing again.
4. Today I decided to dig up a solution, found this thread, opened it up again and looked for the two pins to short... but the chip wasn't there.
5. I found it hiding on the bottom of the board, joined the pins, and the printer has correctly been reporting 219 labels and online for a few hours now... fixed?

PCB says RevD

Adding a couple photos, maybe it's useful to someone, thanks again and... see you next time it stops working 

EDIT: Welp the issue came back again, guess I'll lurk around and wait for a fix lol.

[Cali250402864]

Forgive me for the stupid questions...  I recently fell into the Dymo 550 trap. From what I understand from this thread, the hack requires modification to the hardware in order to modify the code/program?

Is it possible to clone the NFC code onto blank tags? Has anyone tried yet?

[Axis-3790]

This thread is related to a bypass of reading the chip on the 550's. It is through the method of installing an STM32 board between the NFC reader and the main board. You do not necessarily "modify" the hardware but add to it. The STM32 is emulating the chipped labels and just modifying the label count on the NFC. I believe we cannot clone the NFC onto a blank one due to the label count being stored in the dymo itself. I highly recommend reading through the 9 pages of this thread if you are wanting anymore info. I am just another user who is thankful for the bypass as the cost of labels is a literal 10x price difference.

Github w/ instructions on what to do: https://github.com/free-dmo/free-dmo-stm32