//-----------------------------------------------------------------

// Name: Brian Yarbrough

// Class: ECE 382 Section T5, Capt Trimble

// Start: Coulston

// File: lab5.c

// Date: Fall 2014

// Purp: Implement LCD Etch-a-Sketch with the IR remote

//-----------------------------------------------------------------

#include <msp430g2553.h>

#include "head06.h"

int16 packetData[34];

int8 packetIndex = 0;

/*

* main.c

* Initializes the robot

* Waits for a new IR packet to be recieved, then handles the request

*/

void main(void) {

initMSP430(); //initialize system

initIR();

P1DIR |= BIT0 | BIT6; // Enable updates to the LED

P1OUT &= ~(BIT0 | BIT6); // An turn the LED off

GO_STOP;

while(1){

if(packetIndex == 34){

handlePress();

_delay_cycles(LONG_T);

initIR();

}

}

}

/*

* initMSP430()

* Responsible for configuring pins to timers and enables interrupts

* Must be called prior to driving motors

* TACCR1 is the duty cycle %.

* It must be < 60 to prevent burning the motor chip

*/

void initMSP430(){

IFG1=0; // clear interrupt flag1

WDTCTL=WDTPW+WDTHOLD; // stop WD

BCSCTL1 = CALBC1_8MHZ; //calibrate clock

DCOCTL = CALDCO_8MHZ;

P1DIR &= ~BIT3;

P1REN |= BIT3;

P2DIR |= BIT2; // P2.2 is associated with TA1CCR1

P2SEL |= BIT2; // P2.2 is associated with TA1CCTL1

P2DIR |= BIT4; // P2.4 is associated with TA1CCR2

P2SEL |= BIT4; // P2.4 is associated with TA1CCTL2

//ports for direction

P2DIR |= BIT0 | BIT1 | BIT3 | BIT5;

TA1CTL = ID_3 | TASSEL_2 | MC_1; // Use 1:8 presclar off MCLK

TA1CCR0 = 1000; // set signal period

TA1CCR1 = 500;

TA1CCTL1 = OUTMOD_3; // set TACCTL1 to Reset / Set mode

TA1CCR2 = 500;

TA1CCTL2 = OUTMOD_3; // set TACCTL1 to Reset / Set mode

}

/*

* initIR()

*readies the IR sensor to recieve a signal from the remote

* must be recalled after initMSP430() is called

*/

void initIR(){

//IR Pins

P2SEL &= ~BIT6; // Setup P2.6 as GPIO not XIN

P2SEL2 &= ~BIT6;

P2DIR &= ~BIT6;

P2IFG &= ~BIT6; // Clear any interrupt flag

P2IE |= BIT6; // Enable PORT 2 interrupt on pin change

TACTL &= ~TAIFG; // clear flag before enabling interrupts = good practice

TACTL = ID_3 | TASSEL_2 | MC_1 | TAIE; // Use 1:1 presclar off MCLK and enable interrupts

_enable_interrupt();

}

/*

* handlePress()

* copied from Lab05

* decodes which button was pressed on remote

* modified to call appropriate drive function

*/

void handlePress(){

_disable_interrupt();

int32 result = 0;

int32 setter = 0x80000000; //1 in the MSB

char i;

for(i = 2; i<34; i++){ //traverse array

int16 current = packetData[i]; //current element

packetData[0] = 0; //clear element

if(current/10 < 100){ //is a zero

result &= ~setter; //clear bit

}

else {

result |= setter; //set bit

}

setter >>= 1; //rotate setter

}

packetIndex++; //ensure the loop is not reentered

switch(result){ //take appropriate action

case UP:

P1OUT ^= BIT0;

drive(FORWARD);

break;

case DOWN:

P1OUT ^= BIT6;

drive(BACKWARD);

break;

case LEFT:

P1OUT |= (BIT0 | BIT6);

drive(LEFT_T);

break;

case RIGHT:

P1OUT ^= (BIT0 | BIT6);

drive(RIGHT_T);

break;

case EXIT:

drive(STOP);

break;

case CH_UP:

break;

case CH_DW:

break;

case MUTE:

break;

}

initIR();

}

/*

* drive()

* accepts a direction and moves the robot in that direction

*/

void drive(direction movement){

GO_STOP;

_delay_cycles(SHORT_T);

switch(movement){

case FORWARD:

TA1CCTL1 = OUTMOD_7;

TA1CCTL2 = OUTMOD_7;

GO_FORWARD;

break;

case BACKWARD:

TA1CCTL1 = OUTMOD_3;

TA1CCTL2 = OUTMOD_3;

GO_BACKWARD;

break;

case LEFT_T:

TA1CCTL1 = OUTMOD_7;

TA1CCTL2 = OUTMOD_3;

GO_FORWARD;

GO_LEFT;

break;

case RIGHT_T:

TA1CCTL1 = OUTMOD_3;

TA1CCTL2 = OUTMOD_7;

GO_FORWARD;

GO_RIGHT;

break;

case STOP:

GO_STOP;

break;

}//end switch

ENABLE_MOTORS;

}

/*

* interrupt for the PWM

*/

#pragma vector = PORT2_VECTOR // This is from the MSP430G2553.h file

__interrupt void pinChange (void) {

int8 pin;

int16 pulseDuration; // The timer is 16-bits

if (IR_PIN) pin=1; else pin=0;

switch (pin) { // read the current pin level

case 0: // !!!!!!!!!NEGATIVE EDGE!!!!!!!!!!

pulseDuration = TAR;

TACTL = 0;

packetData[packetIndex++] = pulseDuration;

LOW_2_HIGH; // Setup pin interrupr on positive edge

break;

case 1: // !!!!!!!!POSITIVE EDGE!!!!!!!!!!!

TAR = 0x0000; // time measurements are based at time 0

TA0CCR0 = 0xFF00; // create a 16mS roll-over period

TACTL &= ~TAIFG; // clear flag before enabling interrupts = good practice

TACTL = ID_3 | TASSEL_2 | MC_1 | TAIE; // Use 1:1 presclar off MCLK and enable interrupts

HIGH_2_LOW; // Setup pin interrupr on positive edge

break;

} // end switch

P2IFG &= ~BIT6; // Clear the interrupt flag to prevent immediate ISR re-entry

} // end pinChange ISR

// -----------------------------------------------------------------------

// This interrupt is a way of reseting the reciever when something gets messed up

// It also resets packetIndex after the final pulse is recieved

// It is only active while IRPIN is high

//

// Only active when IR pin is being read

// -----------------------------------------------------------------------

#pragma vector = TIMER0_A1_VECTOR // This is from the MSP430G2553.h file

__interrupt void timerOverflow (void) {

initMSP430();

packetIndex = 0;

TACTL &= ~TAIFG; //clear flag

}