Maximum cable lenght between two Piicodev moduls

Hi team,

How long would be the maximum length of a cable for connecting PiicoDev modules together? e.g.
4 Wire Telephone Cable, or CAT5e cable.


Hi Farhad,

The PiicoDev modules use the I2C protocol to communicate so their limitations are based on that. As the name, Inter-integrated-circuit implies it’s made for very short distances.
Some sources say around 1 meter is the longest you can get.
Ultimately it is a result of the capacitance between your cables and the pull up resistance of your data lines.
There is some discussion on stack exchange here: Maximum I2C Bus Length? - Electrical Engineering Stack Exchange
And a look into the mathematics behind the limitations here:
I2C Cabling | Analog Devices


Thank you!
Can I use Adafruit LTC4311 I2C Extender at the end ( or beginning) of a chain of Piicodev modules.


Hi Farhad,

Yeah, it looks like this one would be best placed at the start of the chain. JP from Adafruit has a great video on it here: JP’s Product Pick of the Week 12/1/20 LTC4311 I2C Terminator @adafruit @johnedgarpark - YouTube

If you are keen on doing some conversion you can use a voltage to current converter to send the signal down a massive cable.


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