In this lab exercise you will program the MSP 430 board to play either the Star

Question

In this lab exercise you will program the MSP 430 board to play either the Star Wars Empire March or a

tone when the four switches are set to different values. Specifically:

1. When the switches are 0x0 (binary 0000), the March will play. It will finish before the switches

are examined again.

2. When the switches are 0x1 to 0xF (binary 0001 to 1111), an audible tune will play. It will play

for a very short time, after which the switches are examined again. You may not notice the

break when the switches are examined.

3. Suggestion: wire the switches to Port 2, bits 0 to 3. Wire the speaker to Port1.1

How do put the code in the main part (the on with the color red)? i just don't get it .

// This macro identifies the ports available and provides the delay function

#include "msp430g2553.h"

//These macro define the frequencies for the tunes

#define c 261

#define d 294

#define e 329

#define f 349

#define g 391

#define gS 415

#define a 440

#define aS 455

#define b 466

#define cH 523

#define cSH 554

#define dH 587

#define dSH 622

#define eH 659

#define fH 698

#define fSH 740

#define gH 784

#define gSH 830

#define aH 880

// Prototype functions - always prototype function you use

// that means, identify in inputs and outputs

void delay_ms(unsigned int ms );

void delay_us(unsigned int us );

void beep(unsigned int note, unsigned int duration);

void march();

//****************************************************************************

//

// function main

// Input: Port 2 switches

// Output: none - but calls beep which plays a tune on Port 1.1

// Main driver of Lab 4 - reads switches, calls

// Plays audible tunes - either the Star Wars Empire March or an annoying beep

//

//****************************************************************************

int main( void ){

// Disable the watchdog timer

//PUT YOUR CODE HERE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

//Set the direction for the speaker port and switch ports

//PUT YOUR CODE HERE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

//You will need several lines here

// Define variable that identifies if the switches are slid

int SwitchP2_0 = 0;

int SwitchP2_1 = 0;

int SwitchP2_2 = 0;

int SwitchP2_3 = 0;

int FrequencyTotal = 0; //Relates to 12 Hz, lowest audible frequency

int FrequencyChange = 100; //Relates to 1332 Hz change

//PUT YOUR CODE HERE THAT MAKES A FOREVER LOOP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!   

//Read the slide switches, set the variables based on switch values

//MODIFY THIS CODE BELOW!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

SwitchP2_0 = xxxxxxxxxxxxx;

SwitchP2_1 = xxxxxxxxxxxxx;

SwitchP2_2 = xxxxxxxxxxxxx;

SwitchP2_3 = xxxxxxxxxxxxx;

//If all of switches are 0000, play the Empire March

//MODIFY THIS CODE BELOW!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

if(xxxxxxxxx){

march();

delay_ms(2000);

} // end of if code

else {

//The switches are between 0001 and 1111. Play a tone instead. Based

//on the switches slid, the speaker makes a low (0001) or high (1111) tone

//Feel free to experiment with different settings

if (SwitchP2_0) FrequencyTotal = FrequencyTotal + FrequencyChange*1;

if (SwitchP2_1) FrequencyTotal = FrequencyTotal + FrequencyChange*2;

if (SwitchP2_2) FrequencyTotal = FrequencyTotal + FrequencyChange*4;

if (SwitchP2_3) FrequencyTotal = FrequencyTotal + FrequencyChange*8;

//Make sound proportional to switches

beep(FrequencyTotal, 100);

// Resets frequency total

FrequencyTotal = 0;

} // end of else code

} // end of while loop

} // end of the main program

//YOU SHOULD NOT CHANGE ANY CODE BELOW HERE

//****************************************************************************

//

// function delay_ms

// Input: int ms

// Output: none

// delays for ms milliseconds

// Requires to be linked to the subroutine __delay_cycles (is in msp430g2553.h)

//

//****************************************************************************

void delay_ms(unsigned int ms ){

unsigned int i;

for (i = 0; i<= ms; i++)

__delay_cycles(500);

}

//****************************************************************************

//

// function delay_us

// Input: int us

// Output: none

// delays for us microseconds

// Requires to be linked to the subroutine __delay_cycles (is in msp430g2553.h)

//

//****************************************************************************

void delay_us(unsigned int us ){

unsigned int i;

for (i = 0; i<= 2 * us; i++)

__delay_cycles(1);

}

//****************************************************************************

//

// function beep

// Input: note value and duration of note.

// Output: outputs a pulse on Port 1.1

// Requires to be in the same file as the subroutines delay_us

// Note: Also reads Port 2 -if no switches are set (play the Empire March)

// then add a short delay to improve the sound of the March

//

//****************************************************************************

void beep(unsigned int note, unsigned int duration){

unsigned int i;

unsigned int delay = 10000/note; //This is the semiperiod of each note.

unsigned int time = (duration*100)/(delay*2); //This is how much time we need to spend on the note.

for (i=0;i<time;i++){

P1OUT |= BIT1; //Set P1.1...

delay_us(delay); //...for a semiperiod...

P1OUT &= ~BIT1; //...then reset it...

delay_us(delay); //...for the other semiperiod.

}

if (!P2IN) delay_ms(50); //Add a little delay to separate the single notes

}

//****************************************************************************

//

// function march

// Input: none

// Output: none (beep does this)

// Plays the Star Wars Empire March tune

// Requires to be in the same file as the subroutines beep and delay_ms

//

//****************************************************************************

void march() {

beep( a, 500); beep( a, 500); beep( a, 500); beep( f, 350);

beep( cH, 150); beep( a, 500); beep( f, 350); beep( cH, 150);

beep( a, 650); delay_ms(450);

//first bit

beep( eH, 500); beep( eH, 500); beep( eH, 500); beep( fH, 350);

beep( cH, 150); beep( gS, 500); beep( f, 350); beep( cH, 150);

beep( a, 650); delay_ms(450);

//second bit...

beep( aH, 500); beep( a, 300); beep( a, 150); beep( aH, 400);

beep( gSH, 200); beep( gH, 200); beep( fSH, 125); beep( fH, 125);

beep( fSH, 250); delay_ms(250);

beep( aS, 250); beep( dSH, 400); beep( dH, 200); beep( cSH, 200);

//start of the interesting bit

beep( cH, 125); beep( b, 125); beep( cH, 250); delay_ms(250);

beep( f, 125); beep( gS, 500); beep( f, 375); beep( a, 125);

beep( cH, 500); beep( a, 375); beep( cH, 125); beep( eH, 650);

//more interesting stuff (this doesn't quite get it right somehow)

beep( aH, 500); beep( a, 300); beep( a, 150); beep( aH, 400);

beep( gSH, 200); beep( gH, 200); beep( fSH, 125); beep( fH, 125);

beep( fSH, 250); delay_ms(250);

beep( aS, 250); beep( dSH, 400); beep( dH, 200); beep( cSH, 200);

//repeat... repeat

beep( cH, 125); beep( b, 125); beep( cH, 250); delay_ms(250);

beep( f, 250); beep( gS, 500); beep( f, 375); beep( cH, 125);

beep( a, 500); beep( f, 375); beep( cH, 125); beep( a, 650);

}

Explanation / Answer

I have modified only the main program. Please let me know if you need any thing else.

modified main is as below

int main( void )

{

// Disable the watchdog timer

WDTCTL = WDTPW + WDTHOLD; // Stop watchdog timer

//Set the direction for the speaker port and switch ports

// port2, 0 to 3 are input and port 1.1 is output

P2SEL &= 0xF0 ; 2.0-3 are GPIO -> clear lower 4 bits

P2DIR &= 0xF0 ; 2.0-3 are input -> lower 4 bits to cleared for input

P1SEL &= 0xFD ; 1.1 is GPIO -> clear 1st bit

P1DIR |= 0x02 ; 1st bit to be set for output

// Define variable that identifies if the switches are slid

int SwitchP2_0 = 0;

int SwitchP2_1 = 0;

int SwitchP2_2 = 0;

int SwitchP2_3 = 0;

int FrequencyTotal = 0; //Relates to 12 Hz, lowest audible frequency

int FrequencyChange = 100; //Relates to 1332 Hz change

while(1)

{

//Read the slide switches, set the variables based on switch values

SwitchP2_0 = P2IN & 0x01; // reading the input value of 0th bit

SwitchP2_1 = P2IN & 0x02; // reading the input value of 1st bit

SwitchP2_2 = P2IN & 0x04; // reading the input value of 2nd bit

SwitchP2_3 = P2IN & 0x08; // reading the input value of 3rd bit

// if all the inputs are 0 then P2IN & 0x0F will be zero else 1

if(P2IN & 0x0F)

{

//some input is 1

/*if (SwitchP2_0) FrequencyTotal = FrequencyTotal + FrequencyChange*1;

if (SwitchP2_1) FrequencyTotal = FrequencyTotal + FrequencyChange*2;

if (SwitchP2_2) FrequencyTotal = FrequencyTotal + FrequencyChange*4;

if (SwitchP2_3) FrequencyTotal = FrequencyTotal + FrequencyChange*8;*/

FrequencyTotal = FrequencyTotal + FrequencyChange*(P2IN&0x0F);

//Make sound proportional to switches

beep(FrequencyTotal, 100);

// Resets frequency total

FrequencyTotal = 0;

}//end of if

else

{

//all the swithes are zero

march();

} // end of else

// large delay between reading of switches

delay_ms(2000);

} //end of while loop

}

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