Hi
Problem with long cable is noise, that effect to reliability of system.
Long cable is like absorption antenna, and you know rf is allaways arround.
I2C is single end power bus, that make unbalance power between end point. Mean has dc current flow on data bus.
Problem happen is GND is not same in End Point. Have different between GND, cause by unbalance dc current x wire resistance/Impedance.
Different GND make wrong logic level, noise from RF make wrong clock/data. ESD/EMI damage input port/IC.
So, need to reduce these effect to maintenaince data:
1 - Use buffer/switch IC to isolate I2C bus to main MCU/Processor to increase reliablity of system. If I2C bus failed, that don't make MCU shutdown. Or system only connect to sensor when need and reduce effect of noise to main/ MCU.
2 - Reduce clock frequency of I2C to reduce effect of unbalance, impedance of long cable. Use multiple strand wire cable to reduce impedance. Larger core size cable.
3 - Add RC subbber at end point, MCU side and sensore side to reduce ringing on bus.
4 - Calculate resonant rf frequency with cable length then add decoupling capacitor at end point (<~xxx pF).
5 - Add accelerator IC to recover edge/streng of pull-up resitor. Because step 3&4 increase capacitor load. Look:
https://www.analog.com/en/about-adi...vily-loaded-i2c-smbus-system-reliability.html
6 - Add small ferrite bead on SCL, SDA, GND to reduce common mode noise. Because this is unbalance/ sing-end bus so can't use choke to filter.
7 - Use Vcc 5V higher than 3V3 is better. Check the edge of clock and data with falling edge.
8 - MCU have to config repeat deinit & init_i2c() function after define time or when fail reading event. Some amr-core MCU still run when error but has no operation on I2C bus.
9 - Add more decoupling capacitor for VCC at sensor side.
10 - Add TVS at end point to protect ESD.
11 - Use independent or protected power VCC to supply sensor. This will not make shutdown system if issue happen with cable.
12 - Layout with seperate zone, to reduce effect of noise, ferrite filter, decoupling capacitor, TVS, Accellerator, buffer/switch, independent power supply.
The other solution is use RS485/Rs232 bus, you build a small module to convert I2C to Rs485/232 then connect to main board.
You can also I2C Isolator module to reduce more commond mode noise like
https://www.analog.com/en/parametricsearch/11033#/ and power supply need isolation. This make solution cost higher, you can use opto trick to isolated SCL SDA line
(bidirection line )