arduino diy controller help

[djmx2002]

Hi All,

I am working on my DIY Arduino controller, and i planned to run i2c cables from the controller to the outlet (which has i2c > IO chip). The cable runs about 30' and i found out that it just doesn't work :-/

I think that the i2c can't go that far... does anyone have any ideas on how to make it work? kind of stuck at the moment, cant really figure out what to do....

[sleepydoc]

why so far? Can you have the arduino any closer?

As I recall, I2C requires pull up resistors, do you have these in place? THey may clean up the signal enough. Beyond that, it's difficult to tell. It's quite possible that the cable you're using has enough intrinsic capacitance to cloud the signal. What kind of cable are you using? A different type of cable may make a difference as well.

[djmx2002]

i am running it that far, because the arduino will be placed underneath the aquarium, The same arduino will also be controlling all the equipment in the fish room (adjacent room to the aquarium).

right now i am using the intercom cable, 5 conductors, 5V, GND, 1 digital pin, SDA and SCL.

yet, got the resistors on it.

[djmx2002]

Would something like that solve my issue?

http://www.ebay.com/itm/Active-I2C-Long-Cable-Extender-P82B715-Module-for-Arduino-and-Other-MCUs-/110958301350

[Gorgok]

Apparently there are ICs designed for this job. Here is one: TI P82B715P (http://www.mouser.com/ProductDetail/Texas-Instruments/P82B715P/?qs=sGAEpiMZZMtGSqm70BnklxZAsqaOniqAVwNaoeg64XI%3d)

From the datasheet it sounds like you need 2 of these, one at each end of a long cable used for the bus, with the other side of the chips connecting to the devices/controllers on the bus. Sounds like you could have this long cable with the chips at the end be thought of as an extension cord.

[djmx2002]

Thanks going to give it a shot