Ink jet print head question...

I'm a new Arduino user so excuse my misunderstandings.

I'm going to use an inkjet print head to dose very small amounts of liquid.

I don't need anything "extra" on it, like motors shifting it left and right. I just want each color bay to either fire, or do nothing. (on/off, only "variable" is how long I run it for) Looking at the print head assembly, it has 50 gold contact points with the cable that connects to the rest of the printer.

If I want to run this outside of the printer off of an Arduino board, how do I do that? Run a print command from the computer for one color, then measure the voltages being sent to each contact point?

By doing that, I can learn what the voltage is, and to which contact points, right? I'd then able to use that to program the Arduino.

Thanks!

AFAIK, inkjet head specifications for current generation stuff tends to be very proprietary. There was an HP inkjet development kit for one of their older cartridges that might give you some clues:

http://www.parallax.com/dl/docs/prod/robo/InkjetKitDocs-v1.0.pdf

(I don't know if it's still available.)

Yeah, I had seen that when I was looking around, had trouble finding anything on their site though.

You're probably right about the current generation equipment being very proprietary, my thought was that if all I need to do is get it to dispense a little bit of the fluid, that I could do that by just measuring the signals being sent to each connection when I send a command to print a specific color.

my thought was that if all I need to do is get it to dispense a little bit of the fluid, that I could do that by just measuring the signals being sent to each connection when I send a command to print a specific color

You’re going to need some very sophisticated and expensive signal analysis tools to do this. Even the cheapest low-end Canon inkjet printer has 1,472 nozzles. Good luck decoding and reverse engineering the data stream for that!

If you need to drive a lot of outputs (especially if they require a lot of current), Micrel makes some nice all-in-one serial drivers that can drive a lot of current. You can daisy-chain lots of these together to drive many lines up to 500mA, and use the Arduino's shiftOut call to send the outputs. Internally, they're a Darlington array like that Basic Stamp printer controller uses, but with a serial shift register attached for ease of use.

http://www.micrel.com/page.do?page=product-info/power_drivers.shtml

The MIC5891 would be good for what you're trying - use 1 for every 8 nozzles you need to drive.

-Paul

etracer - I don't need control over each one, just all of them together, or as many as I can easily get.

This inkjet stuff is turning out to be a bit more complex than I thought initially, I might just go down the path of a pump or something, that seems to be about a hundred times easier.