Long Distance I2C

RE: Long Distance I2C

Mr.NCK — Fri, 10 Dec 2021 05:42:54 GMT

Thank you Jonathan

RE: Long Distance I2C

JONATHAN LL — Fri, 19 Nov 2021 13:25:49 GMT

Hi,

Yes, i am here, but i cant recommend any specific type of wire. I2C is not designed for long distance communication.

The I²C specification allows a line capacitance of 400 pF at most. https://infocenter.nordicsemi.com/topic/ps_nrf5340/twim.html?cp=3_0_0_6_35_9#concept_twim_timings

There are some a bunch of forums discussing best practise on how to go about this solution but we at Nordic do not have any explicit experience with this so i can not recommend anything specific. I dont know how noisy the environment is in your application so difficult to say, but shielded wires could be a good idea to reduce chase of extra noise introduces to the system. Capacitance of the wires might be the biggest issues here so different gauge wires will have different max lengths.

bus - Best way to do I2C/TWI over long distance - Electrical Engineering Stack Exchange
Sending i2c over 7 meters | All About Circuits
I2C Long Distance - Using Arduino / Networking, Protocols, and Devices - Arduino Forum
I2C FAQ - EmSA (esacademy.com)
Maximum I2C Bus Length? - Electrical Engineering Stack Exchange

Extender options
Extending I2C Communication Distance with the DS28E17 (maximintegrated.com)
75016527.pdf (nxp.com)

If you have some development kits you could set up your own test and see how well different lengt and type of wires gauge preform in the given environment.

Regards,
Jonathan

RE: Long Distance I2C

Mr.NCK — Fri, 19 Nov 2021 10:28:02 GMT

Hi Jonathan,

Are you there??

RE: Long Distance I2C

Mr.NCK — Thu, 18 Nov 2021 04:42:09 GMT

Hi Jonathan,

The Sensor which we going to use is mlx90614. It uses SMBus communication which uses 100khz (Standard bitrate) as communication rate. for wire, we need to use nearly 2 meters of length. So, we are expecting some suggestions for wire from you.

Thanks & Regards

Navin

RE: Long Distance I2C

JONATHAN LL — Mon, 15 Nov 2021 16:14:23 GMT

I will look in to this, but there are more factors to consider. What communication rate, what is the total capacitance of the wires at that length? Are the wires shielded or not?

Regards,
Jonathan