Is there any known protocol, or known practices, in data transfers between various blocks of a printer, especially in HP printers?
For example, a big HP office printer/photo-copier have its blocks spread all over the printer, sometimes at long distance. The motherboard, the display, the keyboard, the scanner or other parts, all need to talk, and some are very high speed. I doubt they re-invent the wheel for each new model of a printer, so how is the data transfers usually implemented internally?
Are there any chances to reuse an entire block from a big HP printer, for example, the touchscreen/keyboard, or the CCD/scanner (or maybe something else) as a standalone module for other projects?
A couple I pulled apart have been USB just with smaller connectors. These were smaller boards such as the card reader on a photo printer.
For some reason I didn't check if it was USB while I was still having access to the working printer. Now I have only the touch screen and a keypad panel from some other smaller HP smaller printer.
Will look at the connectors and see if it could be a USB hidden there, thank you!
If it's USB, that would be great and awful at the same time, because then I will need USB drivers in order to use them somewhere else.
The couple I tore apart had 5 and 10 pin plugs, for power, ground, D+, D- and shield.
Only need drivers for Windows, use a decent OS and they usually work.
USB within devices is more common than you think, maybe the attitude of the manufacturers is something similar to the phrase 'why re invent the wheel'. Some time ago I stripped down a Compaq laptop for spares and both the keyboard and the touchpad used a USB interface but with a different connector.
Many standard microcontrollers have USB, SPI and I2C built in so these would be the first interfaces I would check for.