Q$3.(65$ pts$)$ Consider an electronic medical gas alarm panel that continuously monitors the pressures of medical air and medical oxygen delivered by the medical gas distribution system to an intensive care unit and triggers alarms as responses to failure in the pressures.

Pressure is monitored by a digital pressure sensor that outputs logic $\backslash (\backslash$mathbf$\{1\}\backslash )$ for normal pressure and logic $\backslash (\backslash$mathbf$\{0\}\backslash )$ for faulty pressure. The sensor has three terminals namely VCC$,$ OUTPUT and GND $($VCC should be connected to $+5$ Vdc $).$

Visual alarm is triggered regarding the output of the sensor$.$ A green LED is lighted up to indicate "normal pressure" while a red LED is lighted up to indicate "faulty pressure".

Design the electronic circuit, develop the flowchart and write the PBPro program for the alarm panel considering

a$.$ The panel houses a PIC$16$F$877$A microcontroller unit running at $\backslash (\backslash$mathbf$\{20\}\backslash$mathbf$\{$~ M H z$\}\backslash )$

b$.$ The medical air sensor is connected to Port B pin $7$ and the red and green LEDs for the medical air pressure are connected to Port B pins $5$ and $\backslash (\backslash$mathbf$\{6\}\backslash )$ of the microcontroller.

c$.$ The medical oxygen sensor is connected to Port B pin $2$ and the red and green LEDs for the medical oxygen pressure are connected to Port B pins $\backslash (\backslash$mathbf$\{0\}\backslash )$ and $\backslash (\backslash$mathbf$\{1\}\backslash )$ of the microcontroller.