Dymo 550 Thermal Printer DRM Hacking

[tooki]

And for those that want an alternative to the Dymo label software, and have support for countless printers including the old Dymos, I've been talking to the author of this software:
https://label.live/
He's also close to releasing his own printer as well.

Looks like a nice app! Do you know whether it will support thermal transfer printers? For durability (both against abrasion as well as against fading in long-term storage or staining due to chemical exposure) they’re practically mandatory.

I’d also love to see it support laminated labels like the Brother p-touch.

[mistial_dev]

And here's 2.25 in x4 in.

[okdc]

I attempted this with the compiled firmware from github and can't seem to get it to work on my 5XL. Any pointers? I appreciate any and all help. I've never worked with a stm32, really only ever toyed with arduino. I flashed the stm32 with a uart and with st-link. Same results. I'm on windows, so compiling isn't as simple as it should be, was trying to avoid making this any more difficult than it already is. Do I need to flash this with linux? I've double checked my solder job and I was actually quite pleased with my work, so I really don't think it's that. The color order was different, but I made sure they all matched up.

The dymo software detects the label properly for about a second and then it returns to unknown label detected.  I've also tried using the reader with the rfid off the roll that came with printer. No change.

The printer power light just flashes like it can't detect anything.

[wraper]

What are those parts with black blobs? Do not look like usual resistors which are needed. Look more like thermistors.

[js_12345678_55AA]

@okdc:

In the pictures it looks like the 2 yellow BOOT jumpers are still both at the "1" position.
This will let the device always enter it's bootloader and the firmware is never run.

=> After flashing the firmware put the boot jumper back to the normal "0" position.

Have a look here:

https://circuitdigest.com/sites/default/files/inlineimages/u/STM32-Operating-and-Programming-Mode.jpg

JS

[okdc]

Thanks for the replies, yes it's a thermistor, it's what I had on hand. I've ordered standard resistors and they'll arrive tomorrow.

Here is what I'm experiencing. I went in programming mode and flashed the pre-compiled firmware using the STM32CubeProgrammer application. I put it back into operating mode and then gave it a go.

Here is a video of the results.
https://photos.app.goo.gl/PuknEDYjVevKyaZ18

Should I remove the reader just to rule that out? Your help is greatly appreciated!

[js_12345678_55AA]

Here is what I'm experiencing. I went in programming mode and flashed the pre-compiled firmware using the STM32CubeProgrammer application. I put it back into operating mode and then gave it a go.
Here is a video of the results.https://photos.app.goo.gl/PuknEDYjVevKyaZ18

The video shows that the printer did not communicate with the STM32 properly. You should observe the same behaviour when you unplug the STM32 completely.

Should I remove the reader just to rule that out? Your help is greatly appreciated!

You can remove the RFID board connection for troubleshooting. The emulation works without RFID board attached.

The emulation will set SKU S0722430  (54 mm x 101 mm / 2.125 in x 4 in / 220 pcs). The PC software should show this.

Questions:

There is a second LED on the blue pill pcb (labeled PC13) which should blink whenever the printer sends something to the STM32.
=> Do you see this LED blinking at all (should blink several times after printer is started / woken up from power save)?

[okdc]

I removed the reader and sured up my solder job. There wasn't any change, also no blinky.  Reflashed it, still no change. I feel like I'm missing something simple here. I've ensured the STM32 is in operating mode.

Update:

Just for the heck of it, I tried a new STM32 and a new Dymo 5XL. Same results. I only ever get a solid power LED, even when the printer isn't "on" and the printer is in sleep mode.

[SaltyDog]

I am having the same issue with the 550... Just a solid red light.

[SaltyDog]

Could it be because I used a STM32F103C6T6? Are you using more than one i2c port?

[js_12345678_55AA]

Could it be because I used a STM32F103C6T6? Are you using more than one i2c port?

The STM32F103C6T6 is a different MCU which only has half of the RAM, half of FLASH and most problematic, only ONE I2C port (the project uses two).
==> This CAN NOT WORK.

However, the complete source and .ioc file is available in the github repo, so you can change the MCU in ST's "STM32CubeMX" software, generate the code, *REMOVE* the second I2C (which is used to connect to the original RFID board) and just create a custom version for your MCU with emulation only.

JS

@OKDC: Could you check the MCU soldered to your blue pill? Maybe it is not a "STM32F103C8Tx"

[okdc]

Ughh, seems to be the potential problem. Good catch!

I should have known better than to trust Amazon. This is what was ordered https://www.amazon.com/dp/B09MLHTHRC (Do not buy)
All text in description, title, etc. says STM32F103C8T6 but the photos show what I received (STM32F103C6T6)

Which is a good thing, I guess. I was losing my mind trying to figure out what I did wrong. I had even ordered a Label Writer 550 just to make sure. It'll be here soon.

[js_12345678_55AA]

Hi,

SaltyDog was spotting the C6T6 problem. I just asked you to check if by chance you have the same issue.

Anyway, I added a warning to the github readme to check for correct STM32F103C8T6.

JS

[SaltyDog]

I can confirm that the new boards I ordered, the correct ones worked straight away, without issue Thank you!

[okdc]

Mind linking where you purchased? My new ones don't arrive until sometime next week.

[SaltyDog]

I am sure you will find them cheaper elsewhere, but I wanted them right away.

https://www.amazon.com/HiLetgo-STM32F103C8T6-Minimum-Development-Learning/dp/B07VKSVM21/ref=sr_1_1_sspa?crid=10ECKNKM29581&keywords=stm32f103c8t6&qid=1649905956&sprefix=STM32F103C%2Caps%2C76&sr=8-1-spons&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEzNENXSkMxTTk0UUVIJmVuY3J5cHRlZElkPUEwODkwMTU2MUZaRFlOMTlIUU1WTCZlbmNyeXB0ZWRBZElkPUEwMTE1NTI4M1ZPU1YwU0cySTY4WSZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU&th=1

[SaltyDog]

I would also like to note that there is no need to mess with the jumper blocks, when you program via STLink.

I prefer this utility. https://www.st.com/en/development-tools/stsw-link004.html

[okdc]

Got it all working when I got the correct blue pill. Thanks so much for everything.

Attached is the FreeDmo TagDump of a 2 5/16 x 4 in (59mm x 104mm) 300 count spool.

Fun fact, I was able to scan the tag without opening the box. Do what you will with that information.

[SirOsis]

Thanks for all your work on this. Ordered my stuff today should have it Friday and hopefully a working printer on Monday!

Would it be possible to disable the capability of the RFID board to write updated values by introducing an open on the voltage line or is that the same voltage that is used to read. Hope that makes sense.

[johnny32]

Pirate Ship supports all LabelWriter 450 models. The Dymo 450 is not as great as the Munbyn thermal labels printer; you can definitely use it with Pirate Ship! Head to Settings > General Settings and change your Label Size to 2x7".

[jonpaul]

We use 450/450 turbo, 450 twin.
Bought some for $5 ea at fleas.

Indeed Zebra printers are the best, but Dymo has adress label correction and USPS barcode

Jon

[jonpaul]

The older model Turbo/450/twin have no DRM or RFID and work fine with clone labels as long as the registration hole is good.

We find these at garage sales, fleas, etc for $5,,25,

550 is hardly worth the effort!

j

[abefroman]

How is everyone mounting the blue pill when everything is programmed correctly? 

[Darxtek]

OK I’m not the biggest programmer or flasher, but I’m stuck at this part I can’t seem to get the matching pins , and my colors are off lol.
Can anyone help.


Soooo close!

[js_12345678_55AA]

OK I’m not the biggest programmer or flasher, but I’m stuck at this part I can’t seem to get the matching pins , and my colors are off lol.
Can anyone help.

What are you trying to do? All the definitions and code is available for STM32F103C8 already. The Pinout definition would only be needed if you want to port it to another STM32 variant.
There are even pre compiled binaries of the firmware available which you just need to flash:

https://github.com/free-dmo/free-dmo-stm32

Scroll down and read the instrcutions, look at "Firmware" => use "option 3" and download a pre compiled firmware, then follow the steps outlined under "Download the firmware to the STM32F103 bluepill board"

JS