Hello,

I don't know if this forum is still active, but I try to ask for help

Until now I was using a PCF8574 home made i2c sensor to multiplex on/off RCX sensors. This works fine since years on my NXT, event with that latest version of RobotC.

I tried to used this sensor with my EV3 with the same program and it doesn't work at all. After having tried lots of modification, I finally used the i2C Test utility.
I send only a byte to the right port . On my NXT, it answers the states of my contactors in a reply byte. On my EV3, it answers a byte that has no sense and doesn't represents the states of my inputs. I tried all configurations of input ports.
Can someone explain me how it is possible to have such behavior difference between NXT and EV3 for a so simple i2C communication test? Is it possible that my electronic stuff has issues not viewable on NXT but only on EV3? Is it a known issue on RobotC?

Thx for your help.