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Topic: Hi can somebody please confirm what the max distance i2c (Read 384 times) previous topic - next topic

johnsmith23

Hi can somebody please confirm what the max distance between arduino can be using  i2c i've trawled the net and there 100s of different answers some say 1 meter and some say 20 and 6 meters

My project will be 5 meters max and 8 ARD Megas some paired and the rest grouped the biggest gap will be 4 meters between groups

Thanks in advance


retrolefty

I2C bus was designed to allow for communications among IC chips on the same PCB or at most within a single chassis at best. However with proper I2C driver/repeaters components added along a bus, I guess it would be possible to extend it to any practical distance required. One could using a O-scope probably optimize a given length/run by adjusting the I2C pull-up resistor values for best observable waveform shape, but there are other interface buses designed for long runs.

I would suggest some extensive real world testing before committing to use I2C.

Lefty  


johnsmith23

OK thanks for the rapid reply I guess when my Ard's arrives in post I should just physically test them out then maybe try a BUS EXTENDER P82B715PN

though there is very limited info on setting up and using one


robtillaart

backgrounder about I2C - http://www.gammon.com.au/forum/?id=10896 -
Rob Tillaart

Nederlandse sectie - http://arduino.cc/forum/index.php/board,77.0.html -
(Please do not PM for private consultancy)

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