Among my favorite failed dorking around experiences is pre-Raspberry, when the Arduino was still hobby-level equipment. This was over a decade ago...
With only a few kilobytes of code, you could send a UDP packet directly to your phone, with an app you "wrote" with just a few lines of code (to receive, without auto-confirmation).
With only a few kilobytes of code, you could send a UDP packet directly to your phone, with an app you "wrote" with just a few lines of code (to receive, without auto-confirmation).