Convert analogic to digital (print)

Hello everybody,

I'm french and I don't speak english very good, so excuse my language mistakes :slight_smile:

I'm going to try to print with an Arduino board.

I explain :

I've got an Arduino Mega 2560, a computer which it has an USB port and an old printer which it has a DB25 port.
USB is digital and DB25 is analogic. So I would like that my arduino could convert the prints that it receive in USB to the DB25 port from my printer.
(I print from my computer to my old printer via my arduino) or if you prefer (I print from my computer to my Arduino which it send it to my printer)

It's only for the fun and the people who will answer "buy a new printer" or others like that won't really help me.

Thanks a lot ! :slight_smile:

d DB25 is analogic

Not in my experience.
If it RS232, then you need level converters, like a MAX232, but if it is Centronics, you don't.

Since the printer is old and has a 25 pin connector, it's likely RS232. If so, you'll need something such as a MAX232 to convert from the Arduino's TTL voltage to that appropriate to RS232 devices. Given that, a trivial sketch would collect data from the serial port and use softserial to push it out to the printer.

Your problem will be converting the USB data into something suitable to send down to your Centronics printer. (BTW this is digital not analogue)
Keep the printer but buy a USB to Centronics printer adaptor like this http://www.amazon.co.uk/USB-Parallel-Centronics-Printer-Cable/dp/B000Q6LTIA

The Mega has a device USB port, not a host USB port, you will need a host shield. It might be easier to use the digital pins as serial.

what printer type is it?

Okey. This is a HP Deskjet 710C. I tried a DB25->USB converter but that didn't work. I dont know how to plug the USB signal in so if I must use digital pins I Will use digital pins :slight_smile: You're the chief :wink: You say DB25 isn't analogic, ok, I thougt it.

A slightly more expensive USB 2 Centronics cable that says it's HP compatible http://www.amazon.co.uk/MY-Link-Parallel-Printer-parrallel-parralell/dp/B000PLXR8G still cheaper that a new printer or an arduino interface.

Ok,

that could work ? http://www.amazon.fr/gp/product/B002JV0X50?qid=1354102748&ref_=sr_1_4&sr=8-4
or maybe http://www.amazon.fr/ABC-Products®-Adaptateur-parallèle-Imprimante/dp/B0011W9JTO/ref=pd_sim_computers_2

The difference is the price, I think.

Again, you will need a USB host shield to drive any interface.

KeithRB:
Again, you will need a USB host shield to drive any interface.

Not needed as OP wanted to use arduino as interface between PC and printer.

(I print from my computer to my old printer via my arduino) or if you prefer (I print from my computer to my Arduino which it send it to my printer)