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| printer_cartridge [2017/09/14 09:47] – add implementing cartridge chip kingkevin | printer_cartridge [2019/04/15 06:17] – [identifying cartridge chip] update link kingkevin |
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| - the family code (last byte of the ROM ID) "0xb3" (decoded from the trace) doesn't match [[https://github.com/owfs/owfs-doc/wiki/1Wire-Device-List|common lists]] (mTC002 it a for a thermocouple. a different manufacturer might have used the same family code) | - the family code (last byte of the ROM ID) "0xb3" (decoded from the trace) doesn't match [[https://github.com/owfs/owfs-doc/wiki/1Wire-Device-List|common lists]] (mTC002 it a for a thermocouple. a different manufacturer might have used the same family code) |
| - the function commands present in the trace (0x0f, 0xaa, 0xa5) [[http://owfs.sourceforge.net/family.html|match]] a couple of devices | - the function commands present in the trace (0x0f, 0xaa, 0xa5) [[http://owfs.sourceforge.net/family.html|match]] a couple of devices |
| - the [[https://www.maximintegrated.com/en/products/digital/memory-products/DS2432.html|DS2432]] matches the usage: 1-Wire (the protocol used) EEPROM (to store the toner level) with SHA-1 authentication (to prevent counterfeit cartridges). The [[http://datasheets.maximintegrated.com/en/ds/DS2432.pdf|Maxim datasheet]] is abridged and does not contains family code and function command codes (lame security by obscurity), but the [[http://pdf.datasheetcatalog.com/datasheet/maxim/DS2432.pdf|Dallas datasheet]] does | - the [[https://www.maximintegrated.com/en/products/ibutton/memory-products/DS2432.html|DS2432]] matches the usage: 1-Wire (the protocol used) EEPROM (to store the toner level) with SHA-1 authentication (to prevent counterfeit cartridges). The [[http://datasheets.maximintegrated.com/en/ds/DS2432.pdf|Maxim datasheet]] is abridged and does not contains family code and function command codes (lame security by obscurity), but the [[http://pdf.datasheetcatalog.com/datasheet/maxim/DS2432.pdf|Dallas datasheet]] does |
| - based on this datasheet I implemented a DS2432 protocol decoder for sigrok, and the capture matches (no bytes missing or exceeding, and the commands order make sense). Only the family code does not match: 0x33 for DS2432, 0xb3 for our chip | - based on this datasheet I implemented a DS2432 protocol decoder for sigrok, and the capture matches (no bytes missing or exceeding, and the commands order make sense). Only the family code does not match: 0x33 for DS2432, 0xb3 for our chip |
| - even the used SHA-1 hash implementation used for authentication matches (I re-implemented and tested it with key material I found later) | - even the used SHA-1 hash implementation used for authentication matches (I re-implemented and tested it with key material I found later) |
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| Thus this chip is a DS2432, either re-branded or cloned. | Thus this chip is a DS2432, either re-branded or cloned. |
| [[https://electronics.stackexchange.com/questions/171329/help-identifying-this-chip-eeprom|Other printers]] (here a filament cartridge for the Stratasys UPrint SE 3D printer) also use this chip, but in a [[https://www.3dprintforums.com/showthread.php/3153-How2-Refill-the-EEPROM-of-the-HP-DesignJet-3D-aka-uPrint|non-secure]] [[https://github.com/bvanheu/stratasys/issues/21|way]]. | [[https://electronics.stackexchange.com/questions/171329/help-identifying-this-chip-eeprom|Other printers]] (here a filament cartridge for the Stratasys UPrint SE 3D printer) also use this chip, but in a [[https://www.3dprintforums.com/forum/stratasys/how2-refill-eeprom-hp-designjet-3d-aka-uprint-3153/|non-secure]] [[https://github.com/bvanheu/stratasys/issues/21|way]]. |
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| ==== implementing DS2432 ==== | ==== implementing DS2432 ==== |
