Secure data transfer via TWI(i2c)?

Question

Do it yourself

Now I am making a device for a car on a microcontroller (atmega) and I need to run 5 meters of cable (from the trunk to the hood).
This cable should periodically transmit data using the i2c / TWI protocol (as I liked it). Will a tire of this length work? How big is the chance of catching interference? What do you advise to do?

Answer 1

CAN is ideal, but two more controllers are required (there are atmegas), plus you need to figure out the bus in this particular car, and don't be afraid to get into it. Another plus is that there is almost certainly a CAN output to the cabin, you can debug data from a smartphone. The option with RS232 is also not bad, but in fact, you can safely use i2c, you may need to lower the bus frequency and, of course, a cable with a good screen. More www.nxp.com/products/interface_and_connectivity/i2c/i2c_bus_repeaters_hubs_extenders/series/P82B715.html

Answer 2

you can use the usual RS232, RS422 is better, and it’s really good - CAN (it’s used in cars;)