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

Download.c

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

#include "Download.h"

/*-------------------------- Module Constants -----------------------------*/

const static char diskWait_ms = 2; //max switch bounce time

const static int downloadWait_ms = 750; //wait time per LED for DL progress

const static int blinkTime_ms = 250; //blink time (on and off) while LEDS are blinking

/*------------------------- Module Definitions ----------------------------*/

typedef enum { NOT_STARTED,

RUNNING,

STOPPED,

COMPLETED,

BLINKING

} DL_STATE_t; //internal state representation

/*-------------------------- Module Variables -----------------------------*/

static char waitingOnDiskEject; //Used to ensure disk is reinserted before download begins

static DL_STATE_t myState; //Internal state

static char diskIn; //Disk status (in or out)

static char downloadProgress; //Number between 0 and 8

static char blinkStatus; //When in blink mode, indicates if the LEDs are on or off

static unsigned int lastUpdateDLTime; //Used to update download progress

static unsigned int lastDiskTime; //Used to update disk status (debounce the switch)

static unsigned int lastBlinkTime; //Used to update blinking of the LEDs when in blink mode

/*-------------------------- Module Functions -----------------------------*/

static void advanceDisplay(void); //Advances LED progress bar to indicate download status

static void pulseShift(void); //Pulses the shift line for the shift register

static void checkDiskStatus(void); //Reads the disk switch with debouncing software

/*---------------------------- Module Code --------------------------------*/

void initDownload(void) {

unsigned int myTime;

myState = NOT_STARTED; //Initialize internal download state

diskIn = !(PTM & BIT0HI); //Read disk status

if (diskIn) //If disk starts in, can’t start download until it

waitingOnDiskEject = 1; //is ejected and then reinserted

else

waitingOnDiskEject = 0;

downloadProgress = 0; //Reset download progress variable

blinkStatus = 0; //When blinking, the LEDs will first turn on

myTime = TMRS12_GetTime(); //Update all the timer variables with the current time

lastUpdateDLTime = myTime; //this needs to be done to make the timing algorithms work

lastDiskTime = myTime;

lastBlinkTime = myTime;

clearDownloadDisplay(); //turn off all LEDs

}

void resetDownload(void) {

initDownload(); //reset download is just a wrapper for initDownload

}

char isDiskIn(void) {

checkDiskStatus(); //read disk status with debouncing software

return (diskIn);

}

void clearDownloadDisplay(void) {

int i;

//clear out shift register with all zeros

for (i=0; i<10; i++) {

PTAD = PTAD & BIT6LO;

pulseShift();

}

}

DOWNLOAD_EVENT_t checkDownloadEvents(void) {

unsigned int myTime = TMRS12_GetTime();

checkDiskStatus(); //read disk status with debouncing software

//state machine using internal state

switch(myState) {

case NOT_STARTED:

if(diskIn) {

if (!waitingOnDiskEject) {

myState = RUNNING;

downloadProgress = 1;

advanceDisplay();

lastUpdateDLTime = myTime;

return DOWNLOAD_STARTED_EVENT;

}

else {

blinkDownloadLEDs();

return DOWNLOAD_NO_EVENT;

}

}

else {

waitingOnDiskEject = 0;

blinkDownloadLEDs();

return DOWNLOAD_NO_EVENT;

}

break;

case RUNNING:

if(diskIn) {

//check if enough time has passed to progress progress bar (LEDs)

if((myTime - lastUpdateDLTime) > downloadWait_ms) {

lastUpdateDLTime = myTime;

downloadProgress++;

advanceDisplay();

//if all 8 LEDs are already lit up, download is complete

if(downloadProgress > 8) {

myState = COMPLETED;

return DOWNLOAD_COMPLETE_EVENT;

}

}

}

else {

//if disk isn’t in, download cannot progress

myState = STOPPED;

return DOWNLOAD_STOPPED_EVENT;

}

break;

case STOPPED:

if(diskIn) {

lastUpdateDLTime = myTime;

myState = RUNNING;

return DOWNLOAD_STARTED_EVENT;

}

break;

case COMPLETED:

//once the download is complete, just blink LEDs

blinkDownloadLEDs();

return DOWNLOAD_COMPLETE_EVENT;

break;

}

return DOWNLOAD_NO_EVENT;

}

void blinkDownloadLEDs(void) {

char i = 0;

unsigned int myTime = TMRS12_GetTime();

//check if enough time has passed for the LEDs to be blinked (switch from on to off or vise versa)

if ((myTime - lastBlinkTime) > blinkTime_ms) {

lastBlinkTime = myTime;

//fill shift register with zeros or ones

for (i=0; i<8; i++) {

if (blinkStatus)

PTAD = PTAD & BIT6LO;

else

PTAD = PTAD | BIT6HI;

pulseShift();

}

blinkStatus = !blinkStatus;

}

}

static void checkDiskStatus(void) {

unsigned int myTime = TMRS12_GetTime();

//update diskIn if diskWait_ms worth of time has passed (debounce)

if ((myTime - lastDiskTime) > diskWait_ms) {

diskIn = !(PTM & BIT0HI);

lastDiskTime = myTime;

}

}

static void advanceDisplay(void) {

//load a 1 into the shift register (turns on the next LED)

PTAD = PTAD | BIT6HI;

pulseShift();

}

static void pulseShift(void) {

int j=0;

PTAD = PTAD & BIT7LO;

for (j=0; j<100; j++) {

}

PTAD = PTAD | BIT7HI;

}