hosseinzr:
For the relay channel temperature, ..well, it still becomes hot when the relay is connected.
That's exactly what we needed to know. If that relay is very hot to touch, and if you've done the measurements on applied input voltage, and input current....and coil resistance measurement, and you're confident that you've done everything correctly ...... then it could be time for an upgrade and get some beefier relay that can handle the situation better.
If you get a multimeter and measure the applied input voltage.... and if it's 5V DC, then that's good. If the measured input current conforms to specs, then that's good too. If everything is as it should be, and if you get this heating issue, then you could consider trying those other kinds of relays --- even ones with heat-sinks on them.
In your diagram, the arduino is not even connected up. So it's impossible to guess what's going on.