Pin compatible as in "you can stick both in the same socket" then definiltely no, and that's because the Uno has female headers and the Nano has male headers.
Pin compatible as in "they have the same number and designations at their pins" then yes.
Pin compatible as in "you can stick both in the same socket" then definiltely no, and that's because the Uno has female headers and the Nano has male headers.
Pin compatible as in "they have the same number and designations at their pins" then yes.