$(20\%)1.$ Draw a diagram of an embedded system wihch includes a microcomputer interfaced to external physical devices.

$(60\%)2.$ Design a digital door lock using $3$ switches.

$(30\%)$ a$)$ Identify the general specifications and create a list of requirements and constraints.

$(30\%)$ b$)$ Draw the flowchart of your solution.

$(20\%)3.$ Write a function in C that reads P$3\mathrm{.}2$ and sets P$4\mathrm{.}0=0$ if P$3\mathrm{.}2=0,$ otherwise it should set P$4\mathrm{.}0=1$ if P$3\mathrm{.}2=1.$ Assume that you connrect a swi to P$3\mathrm{.}2$ and a LED to P$4\mathrm{.}0.$ Draw the schematic diagram $($circuit$)$ of your solution.