Task $2$: Exploring Sleep Modes with Wake$-$Up Button

$1.$ Objective: Put the Arduino into Power$-$down sleep mode to conserve power and wake it up using a button interrupt.

$2.$ Instructions:

$-$ Configure the Arduino to enter Power$-$down mode when idle.

$-$ Attach a button to pin $\backslash (\backslash$mathbf$\{3\}\backslash )$ to wake the Arduino when pressed.

$-$ In sleep mode, all unnecessary functions are disabled, and the Arduino only wakes up when the button interrupt is triggered.

$3.$ Code Template:

$```$

#include

#include

const int buttonPin $=3$;

void setup$()\{$

pinMode$($buttonPin$,$ INPUT$\_$PULLUP$)$; $//$ Set button as input with pull$-$up

attachInterrupt$($digitalPinToInterrupt$($buttonPin$),$ wakeUp, FALLING$)$; $//$ Interrupt

on button press

Serial.begin$(9600)$; $//$ Optional: for monitoring in Serial

Monitor

$\}$

void loop$()\{$

Serial.println$("$Going to sleep..."$)$:

delav$(1000)$;

$//$ Configure sleep mode

set sleep$\_$mode$($SLEEP$\_$MODE$\_$PWR$\_$DOWN$)$;

sleep enable$()$;

sleepmode$()$; $//$ Put the Arduino to sleep

$//$ The Arduino resumes here after wake$-$up

Serial.println$("$Woke up$!"\backslash )$;

delay$(1000)$: $//$ Wait a moment before going back to

sleep

$\}$

void wakeUp$()\{$

$//$ This function just interrupts sleep mode; no code needed

$\}$

$```$

Questions and Analysis

$1.$ Task $1$: Describe how CTC mode allows for precise timing control without using delav$().$ How does changing the prescaler or compare match value affect the blink interval?

$2.$ Task $2$: How does Power$-$down mode save power compared to other sleep modes? Describe the function of the button interrupt in waking up the Arduino from sleep mode.