I am using RJ45 for a 1-wire bus of DS18B20 sensors connected by 3 conductors to +3.3v, ground, and data on a Raspberry Pi 3B+. While I don’t definitively have plans to use I2C over the same cable, I’d like to use a pin-out that would allow that to/from the same RPi. If I used the SparkFun Differential I2C bus extender board, pins 3 and 6 would be available for 1-wire. The main question is, Would I be able to share a line for either VCC or GND for both 1-wire and an I2C bus extender, thus sharing one line of my 1-wire bus with one line of the I2C bus? I suspect it would be “sub-optimal”, but might it work? Any suggestions for the pin-out of such a configuration would be appreciated.
You could share VCC and ground for both I2C and 1 wire if you wanted too. Your data wire for the 1 wire bus would need to connect to either pin 3 or pin 6 on the RJ45 connector though.
Thanks.