8 ms·

Man-in-the-Middle PCB Unlocks HP Ink Cartridges

82 points by kidbomb 2y ago

RockRobotRock 2y ago
One of my old professors worked at HP and chatted about his involvement in putting ICs in ink cartridges. From what I remember hearing, each one is flashed with calibration data to improve the print quality. Does anyone know if this is still true, or if it makes that much of a difference?
- blackeyeblitzar 2y ago
  At least on my HP printer, there is a process (I think called alignment?) to self-calibrate new cartridges. I am not sure if that is different from the type of calibration you’re talking about (maybe about colors). However, I’ve personally not found differences between using the printer’s own calibration processes and not doing anything. Nor have I found significant differences between first and third party cartridges. Some third party cartridges will print a little bit ‘fuzzier’, or maybe ‘thicker’ is the right way to put it. But not in a way that makes the printing worse, as much as different.
- whoopdedo 2y ago
  HP cartridges attach the thermal print head to the ink tanks. The calibration is likely for controlling those heads. Each one has tiny heating elements that need to vaporize the ink at a precise temperature. Thermal heads eventually need to be replaced. Compare to Epson printers that use piezoelectric heads. Those mechanically push droplets through. This is more complicated, but makes smaller dots.
- neuralRiot 2y ago
  The interposer could block or spoof just the “ink level” data and let the rest pass through.
Brett_Riverboat 2y ago
As much as I love giving the middle finger to a company as awful as HP, people need to stop supporting garbage companies like this and then this wouldn't be necessary.
- hedora 2y ago
  Yeah. Either buy their printers and throw them away when the sample ink runs out (because, while you are correct about HP, you are also a terrible person that hates the earth), or just buy from a different brand. Having said that, we have an old Samsung laser printer, and the Samsung printer business was bought by HP since we got it. Recently, HP started shorting me on toner in the replacement cartridges (they cartridges go streaky with 25%+ “toner remaining”). Switching to third-party ones that bypasses HP’s authenticity checks was clearly the right move (they’re higher quality, cheaper, and also, screw hp).
- solardev 2y ago
  As an infrequent printer (a few pages every few months), their ink subscription plan (Instant Ink) is awesome for us. For $1/mo you get 10 pages (color included), and overages are 10 cents/pg. So basically for $12 a year we can have a home printer but never have to worry about cartridges. They just show up in the mail when we need more, and the used ones can be recycled in the included mailer.
  - zephyreon 2y ago
    > For $1/mo you get 10 pages (color included), and overages are 10 cents/pg. The math works out when I think about it but for some reason I’m still floored by the fact that $12 only gets you 10 pages of paper for an entire year.
    - askvictor 2y ago
      10 pages per month. So $12 gets you 120 pages.
      - 2y ago
rustcleaner 2y ago
Why no FOSS color pencil or pen plotter with robotic paper stack management (next sheet, and bonus: turn-over), ready to 3D print, flash onto pis, and forever replace the supply chain cumbersome ink and toner-based printing?? We can 3D print, why no easy common pencil/pen printer replacement plotters?!!
- lazide 2y ago
  Edge case of an edge case I imagine. I can’t remember the last time I saw a plotter in a store either. That said, it wouldn’t be hard to convert any standard 3D printer into a plotter. Keep Z at 0, rubber band a marker to the side of the print head is probably all it would take.
- rcxdude 2y ago
  Plotters don't really represent most people's use-cases. They're slow, and hard to use because they work with vector representations, so you can't really just print an arbitrary document and get acceptable results.
- immibis 2y ago
  Because you didn't create it yet.
- mystified5016 2y ago
  Plotters are really only good at drawing vector plots. Graphs, schematics, line drawing kind of stuff. Plotters are very bad at text. I'd wager that something like 99% of all pages printed annually are exclusively text and/or raster images (photos). Very close to nobody has a use for a plotter, and traditional printers can do 99.99% of the jobs a plotter can do. There's simply not one reason for the average consumer to use a plotter. If you're in an industry where you do actually need a plotter, they're available at industrial prices. Plotters are cool, but they were only useful when the only other option was monochrome dot matrix. Even then they were extremely limited and not widely used. If plotters can't compete with dot matrix there's no point even discussing whether they can compete with inkjet or laser.
- eternityforest 2y ago
daghamm 2y ago
I LOVE this! A little bit for sticking it to the man but mostly for doing a crazy MITM for cheap. If anyone here has access to one of these devices, please try to capture the firmware and the traffic for us.
xhkkffbf 2y ago
Certainly very clever. The only thing that bugs me about it is that I like the economic effects of the DRM. I don't print very much and the DRM lets HP sell the printers for next to nothing because they'll make it up on the overpriced ink cartridges. If they're forced to sell the cartridges at close to cost, the printers will soar in price. Epson makes one with big tanks that's much higher in price for those that don't want DRM.
blowsand 2y ago
The Big Ink lobby is alive and well. https://www.dailynews.com/2024/08/13/counterfeit-printer-cartridges-should-be-banned-says-la-councilman/ https://www.dailynews.com/2024/08/13/counterfeit-printer-car...
neuralRiot 2y ago
This remembers me of the “sim unlockers” MITM flex boards.

82 points by kidbomb 2y ago

One of my old professors worked at HP and chatted about his involvement in putting ICs in ink cartridges. From what I remember hearing, each one is flashed with calibration data to improve the print quality. Does anyone know if this is still true, or if it makes that much of a difference?

blackeyeblitzar 2y ago
At least on my HP printer, there is a process (I think called alignment?) to self-calibrate new cartridges. I am not sure if that is different from the type of calibration you’re talking about (maybe about colors). However, I’ve personally not found differences between using the printer’s own calibration processes and not doing anything. Nor have I found significant differences between first and third party cartridges. Some third party cartridges will print a little bit ‘fuzzier’, or maybe ‘thicker’ is the right way to put it. But not in a way that makes the printing worse, as much as different.
whoopdedo 2y ago
HP cartridges attach the thermal print head to the ink tanks. The calibration is likely for controlling those heads. Each one has tiny heating elements that need to vaporize the ink at a precise temperature. Thermal heads eventually need to be replaced. Compare to Epson printers that use piezoelectric heads. Those mechanically push droplets through. This is more complicated, but makes smaller dots.
neuralRiot 2y ago
The interposer could block or spoof just the “ink level” data and let the rest pass through.

Brett_Riverboat 2y ago

As much as I love giving the middle finger to a company as awful as HP, people need to stop supporting garbage companies like this and then this wouldn't be necessary.

hedora 2y ago
Yeah. Either buy their printers and throw them away when the sample ink runs out (because, while you are correct about HP, you are also a terrible person that hates the earth), or just buy from a different brand. Having said that, we have an old Samsung laser printer, and the Samsung printer business was bought by HP since we got it. Recently, HP started shorting me on toner in the replacement cartridges (they cartridges go streaky with 25%+ “toner remaining”). Switching to third-party ones that bypasses HP’s authenticity checks was clearly the right move (they’re higher quality, cheaper, and also, screw hp).
solardev 2y ago
As an infrequent printer (a few pages every few months), their ink subscription plan (Instant Ink) is awesome for us. For $1/mo you get 10 pages (color included), and overages are 10 cents/pg. So basically for $12 a year we can have a home printer but never have to worry about cartridges. They just show up in the mail when we need more, and the used ones can be recycled in the included mailer.
- zephyreon 2y ago
  > For $1/mo you get 10 pages (color included), and overages are 10 cents/pg. The math works out when I think about it but for some reason I’m still floored by the fact that $12 only gets you 10 pages of paper for an entire year.
  - askvictor 2y ago
    10 pages per month. So $12 gets you 120 pages.
    - 2y ago

rustcleaner 2y ago

Why no FOSS color pencil or pen plotter with robotic paper stack management (next sheet, and bonus: turn-over), ready to 3D print, flash onto pis, and forever replace the supply chain cumbersome ink and toner-based printing?? We can 3D print, why no easy common pencil/pen printer replacement plotters?!!

lazide 2y ago
Edge case of an edge case I imagine. I can’t remember the last time I saw a plotter in a store either. That said, it wouldn’t be hard to convert any standard 3D printer into a plotter. Keep Z at 0, rubber band a marker to the side of the print head is probably all it would take.
rcxdude 2y ago
Plotters don't really represent most people's use-cases. They're slow, and hard to use because they work with vector representations, so you can't really just print an arbitrary document and get acceptable results.
immibis 2y ago
Because you didn't create it yet.
mystified5016 2y ago
Plotters are really only good at drawing vector plots. Graphs, schematics, line drawing kind of stuff. Plotters are very bad at text. I'd wager that something like 99% of all pages printed annually are exclusively text and/or raster images (photos). Very close to nobody has a use for a plotter, and traditional printers can do 99.99% of the jobs a plotter can do. There's simply not one reason for the average consumer to use a plotter. If you're in an industry where you do actually need a plotter, they're available at industrial prices. Plotters are cool, but they were only useful when the only other option was monochrome dot matrix. Even then they were extremely limited and not widely used. If plotters can't compete with dot matrix there's no point even discussing whether they can compete with inkjet or laser.
eternityforest 2y ago

daghamm 2y ago

I LOVE this! A little bit for sticking it to the man but mostly for doing a crazy MITM for cheap. If anyone here has access to one of these devices, please try to capture the firmware and the traffic for us.

xhkkffbf 2y ago

Certainly very clever. The only thing that bugs me about it is that I like the economic effects of the DRM. I don't print very much and the DRM lets HP sell the printers for next to nothing because they'll make it up on the overpriced ink cartridges. If they're forced to sell the cartridges at close to cost, the printers will soar in price. Epson makes one with big tanks that's much higher in price for those that don't want DRM.

blowsand 2y ago

The Big Ink lobby is alive and well. https://www.dailynews.com/2024/08/13/counterfeit-printer-cartridges-should-be-banned-says-la-councilman/ https://www.dailynews.com/2024/08/13/counterfeit-printer-car...

neuralRiot 2y ago

This remembers me of the “sim unlockers” MITM flex boards.