Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@...> wrote:
>
> I did some more testing.
> It seems the stupid printer really notices if the value in the chips 
> is  
> different from the value in it's own memory.
> Because i noticed the writing is only done when the power is 
> removed. So i  
> simply pulled the chips before switching off. But at next power up 
> the  
> printer did a cleaning cycle.
> 
> I'm still not sure how the chips work. The readout is clear, there 
> are 4  
> transmissions, i think one for each chip. It's always clock and 
> data, very  
> normal. But for writing there seems also to be some fast clock, and 
> then  
> some slow clock. Any idea what is transmitted there? It is only a 
> single  
> block fast, then slow, not 4 blocks fast/slow fast/slow fast/slow  
> fast/slow as i would have expected. How does it write to the 4 chips 
> then?
> 

Epson printers store the ink level information on the chips, not in 
the printer. If you take one set of cartridges out of the printer, and 
put it in another, it will still show the ink depleted. The printer 
checks for this data, and also checks to see if they are Epson branded 
chips (aftermarket regular chips and auto-reset chips were built from 
scratch to avoid patent infringement, while they work, they are not 
the same, and the printer can tell). The printer should not have a 
problem with the chips being re-set, otherwise the $10 resetters from 
Staples wouldn't work for people who refill their cartridges. Unless 
you mean you are resetting while the printer is still on and not in 
cartridge-change mode, which might confuse it.

If a chip is reset to 100%, the printer will do a very full, intense 
cleaning cycle, as it thinks that a new cartridge has been installed 
and wants to start the ink flow properly. Newer generation auto-reset 
chips only reset to 90%, so the printer never does the full purge 
again. However, Epson printers also tend to do an ink cleaning 
whenever you turn the printer on. This seems like a huge waste of ink, 
but on the C-series printers with OEM Durabrite ink, you do NOT want 
the ink in the cart to run out, and you DO want the printer to run 
massive amounts of cleaning cycles, otherwise the quick dry acrylic 
enamel they call ink will dry up in the printer within days and wreck 
it.