Arduino nano just stops randomly

Other Hardware Home Automation
10

Or this doesn't reset whole arduino?

My understanding from reading Wire.cpp is that it does not reset the whole Arduino.

Sets the TWI timeout.
*

  • This limits the maximum time to wait for the TWI hardware. If more time passes, the bus is assumed
  • to have locked up (e.g. due to noise-induced glitches or faulty slaves) and the transaction is aborted.
  • Optionally, the TWI hardware is also reset

How big should be capacitor?

As big as you've got. 100uf or larger.