Maximum Length of an I2C cable

[copterrichie]

I am thinking of adding a Compass to my VTOL (Only have a MPU-6050 now) and was thinking of mounting it on the tail or somewhere in between. Question, how long can the I2C cable be or is there any limitations?

Thank you.

[copterrichie]

I guess I could just try it and see what happens.

[copterrichie]

Just thought I would share the results, now to put this to the test.

What is the maximum distance of the I2C bus?

This depends on the load of the bus and the speed you run at. In typical applications, the length is a few meters (9-12ft). The maximum capacitive load has been specified (see also the electrical Spec's in the I2C FAQ). Another thing to be taken into account is the amount of noise picked up by long cabling. This noise can disturb the signal transmitted over the bus so badly that it becomes unreadable.

The length can be increased significantly by running at a lower clock frequency. One particular application - clocked at about 500Hz - had a bus length of about 100m (300ft). If you are careful in routing your PCB's and use proper cabling (twisted pair and/or shielded cable), you can also gain some length.

http://www.esacademy.com/en/library/technical-articles-and-documents/miscellaneous/i2c-bus/frequently-asked-questions/i2c-faq.html

[Peter]

Thanks, I was also curious. I have a 25cm cable to the compass on the rear of my quad...