This project continues at http://nerdipedia.com
My CIS page.
What is a Intellidge ink chip.
This is the sort of thing I got. No
Convert to binary and some patterns emerge.
Below is one chip being read at startup, there
Below is the complete shutdown stream. Again we
The first 3 bits appear to be the
I’m sure I can reset 3 of the chips
The current set up is for
Shorting the data to ground may be a
1’st October. – reading the chip without the printer.
don’t really need to do this but I wanted to see if I really
understood the protocol. I wrote code for the micro to act as a
master for the chip. I knew the chip was a low voltage part but I
hoped it would be 5 volt tolerant and save me some trouble. After
getting no sense out of two chips and confirming the printer couldn’t
read them either I assume I’ve killed them. I went shopping and
bought 3V3 zeners and 330R resistors to limit the output of the micro
port to 3V3. Data started to flow. The micro would not read it
because is was below the input threshold so I added a pull up to the
data pin (on the micro side of the 330R current limiting resistors so
the inkchip didn’t see 5V). I could then read the contents of the
then spent the afternoon trying to write to it without any success.
2’nd October – reseting the chip without the printer.
sleeping on it, I wrote a better trigger routine for my data-logging
program so I could get a better look at what the printer did
differently. The trace revealed all.
you see here is the printer starting a write sequence at normal speed
then after transmitting the address and write bit the clock (2’nd
from bottom) slowed down to around 1 Khz. I wrote a “slow
write” routine and presto I can write to it. My code simply
writes zeros to the first 8 bits in the chip. I repeat the process 7
timse using every chip address. The proof was to take an empty
cartridge – zap it and feed it to the printer. The printer said yum
and did it’s charging thing – then showed a full cartridge on the
status monitor. I won’t bore you with another image of it. A chip
reseter could be made with a $2 micro and not much else – the
socket is a problem. Most people can’t program micros but for those
who can it is trivial now that the protocol is knonw. My hacked about
code is too ugly to show here.
Alan Chan has sent me this hoping it would help
people ID their chips.
My home page.