I2c cable length

Anyone know off hand is there a limit to how long the jumper cables can be?

I believe the rule of thumb is as short as possible, so immediate connections to neighbouring modules.


what @Catchthehare believes is also the recommendation i remember from going down the rabbit hole of i2c…
however, when i started out to connect a sweet sixteen/16n to the er-301 i had the sweet sixteen sitting in a different case. also, i wanted to keep things flexible. so i soldered a stereo jack to the i2c connections on the er-301 and experimented with simple stereo hifi cables of different lengths between the er-301 and sweet sixteen/16n, which also come with stereo jack outputs for the i2c connection.
today my sweetsixteen is sitting directly in the row above the er-301. and it is still connected with this cheap stereo cable of 1m length behind the panels. so far, i didn’t experience any noticable issues, but maybe my personal requirements aren’t that high. with the exception of latency, which i tested thoroughly when i was experimenting with trigger and “velocity” data thorugh the sweet sixteen.

so, if you have good reasons to use longer connections (e.g. big case or different case/ external devices like a desktop version of a 16n…), you should definitely go and try longer cables and see whether you’re happy with the results. with a jack on the er-301 you can simply swap different cable lengths. though, don’t forget to power down everything before changing connections :wink:


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I’ve got 30cm dupont cables, Ios (disting ex) somewhere said he has tested 40cm with no issues.