I/O interfacing with 12-24 voltage levels.

Hello. I need to control several 12V and 24V logic lines for a project, but the problem is, I need this to be a two-way communication, this is, each line can be an input or output. I used level translators before, but for 3.3-5V and the like, the question is: anybody knows some kind of level translator for voltage levels like 12 and 24 volts? Thanks.

Try this level shifting approach. It is designed for I2C but will work with any bidirectional signal at two voltage levels.

http://ics.nxp.com/support/documents/interface/pdf/an97055.pdf

or look at this:- http://forum.sparkfun.com/viewtopic.php?p=16942

you could try the standard transistor for the arduino switching 12V with a 5V (this is the bit you probably knew :wink: )
As for 12V talking to the arduino if the current is not more than 1A:

You could also go for a voltage regulator that takes in 12-24 V and regulates it to 5V. This might be a 2-stage rocket 24v to 12v and 12v to 5V. The circuits generate heat so heatsink is probably a good idea.

David

@Grumpy_Mike: I didnt think of this solution, just genius ;)

@David Pello: Do take the advise of the electronic god Grumpy_Mike! 8-)

Try this level shifting approach. It is designed for I2C but will work with any bidirectional signal at two voltage levels.

http://ics.nxp.com/support/documents/interface/pdf/an97055.pdf

Ohh nice, that's the point, cause I need that bidirectional way. Now I just need to find some nice fast mosfets that can support 24V. Thanks.