DSP Applications and Student Projects - Digital Signal Processing and Applications with the C6713 and C6416 DSK - page 365

// EMIF.LCD.c Core C program. Displays spectrum to LCDs through EMIF
#define IOPORT 0xA1111111 //EMIF address

int *ioport = (int *)IOPORT; //pointer to get data out

int input, output; //temp storage

void set_LCD_characters(); //prototypes

void send_LCD_characters();
void init_LCD();
void LCD_PUT_CMD(int data);
void LCD_PUT_CHAR(int data);
void delay();
float bandage[16]; //holds FFT array after downsizing

short k=0, j=0;
int toprow[16] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int botrow[16] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
short rowselect = 1; //start on top row

short colselect = 0; //start on left of LCD

#define LCD_CTRL_INIT 0x38 //initialization for LCD

#define LCD_CTRL_OFF 0x08
#define LCD_CTRL_ON 0x0C
#define LCD_AUTOINC 0x06
#define LCD_ON 0x0C
#define LCD_FIRST_LINE 0x80
#define LCD_SECOND_LINE 0xC0

//address of second line

main()
{
..
init_LCD(); //init LCD

while(1) //infinite loop

{
for(k=0; k<16; k++){ //for 16 bands

float sum = 0; //temp storage

for(j=0; j<8; j++) //for 8 samples per band

sum += x1[8*k+j]; //sum up samples

bandage[k] = (sum/8); //take average

}
set_LCD_characters(); //set up character arrays
send_LCD_characters(); //put them on LCD
} //end of infinite loop
} //end of main

interrupt void c_int11() //ISR

{
output_sample(bandage[buffercount/16]); //out from iobuffer
..
}
void set_LCD_characters()

//to fill arrays with characters

{
int n = 0; //temp index variable

for (n=0; n<16; n++)
{
if(bandage[n] > 40000) //first threshold

{
toprow[n] = 0xFF; //block character

botrow[n] = 0xFF;
}

FIGURE 10.13. Core C program using a C-coded FFT function to display the spectrum to
LCDs through EMIF ( EMIF_LCD.c ).