Optically Isolated Parallel Port I2C Adapter

parport i2c

I2C is a simple communications bus similar to 1-wire, which we’ve talked about earlier. [hnch] has built a really simple I2C parallel port interface. It’s optically isolated so you don’t have to worry about a mistake frying your computer. I2C modules already come with the Linux kernel. It will even treat temperature sensors you attach exactly like the ones you have on your motherboard so you can monitor them using ordinary software like gkrellm. There are lots of other devices that use I2C as well. [hnch] has a nerdity gallery and will gladly write up any other project you’d like information on.

20 thoughts on “Optically Isolated Parallel Port I2C Adapter

  1. hmmm, you cant really say that this is a hack.
    i mean, if he used resistors from junk and stuff, it would be okey, but since he dont, why dont eliot just call it buy-electroincs-from-the-store-and-make-stuff-out-of-it-day?
    im not saying this was cool, im saying that it aint a hack…

    mahder bitch

  2. hi all, im steve preece’s mental doctor. i cant tell you clasified information, but i can tell you this, steve preece is either retarded or 9 years old.

  3. mastershake916 / steve preece’s phsycysatrist, thanks guys. And steve if you yell at me before I say something, then you allready know what you put is retarded enough that I’m going to say something, so why would you put it in the first place? You don’t have any relation to Anthony Rico do you?

  4. @ bitch,
    How is this not a hack? This is a lot better then some of the stuff I’ve seen recently. by your logic anything using off the shelf components doesn’t count. I think you just feel left out because you can’t solder and you use winblows.

  5. Yawn… These little flame wars are becoming tiresome. I say from now on Steve just doesn’t exist. Who’s with me?

    Anyway, neat little hack to add external i2c support. Great for adding new temp sensors and the such. I wonder how hard software to control other i2c devices like digital volume controls would be to write? Hmmm… Network controlled amp anyone?

  6. #12 agreed
    #15 nay — its a good thing that every submission requires an email response… you really can’t get more demanding from the users than that (other than requiring more information every time you post)

    Eventually s/he’s gonna say something to piss off the admin… which in turn his/her eMail will be posted and s/he’ll expirience the wrath of the hackaday mob in addition to whatever free porn subscriptions users happen to find :P

  7. @no.13: get yourself the data sheet of the i2c device, and write into the corresponding registers. the sources of the i2c package from lm_sensors could be of interest. simply open() /dev/i2c-X, ioctl() to the corresponding slave address and read()/write(). the infrastructure is included in the stock linux kernel (for instance, tv cards implement a system-wide generic i2c bus, usually by bit-banging some GPIO lines on the chip, this bus is needed for the tuner or for the switching the input on multi-input capture cards).

  8. I have need to optically isolate an HP Oscilloscope and a printer using a parallel bus. We are making HV measurements with the scope (floating ground) and need to talk to the printer which is grounded. Is there a device already out there that will do what I want?

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.