xtest17_5.c

AT91sam7s 256 B/D example

/* ========================================================================== */
/*	      Xtest17_5.c : Digital Oscilloscope on GLCD Module		      */
/* ========================================================================== */
/*			  Designed and programmed by Duck-Yong Yoon in 2007.  */

#include "AT91SAM7S256.h"
#include "lib_AT91SAM7S256.h"
#include "OK7S256ads.h"
#include "OK7S256GLCD.h"

volatile unsigned int n;			// interrupt count (0-110)
volatile unsigned int AD_data, AD_flag;		// A/D data and flag
unsigned int ydot;

void PIT_ISR(void)				/* PIT interrupt service routine */
{ unsigned int i, sum;

  AT91F_PITGetPIVR(AT91C_BASE_PITC);		// clear PITS

  sum = 0;
  for(i=0; i<16; i++)
    { AT91F_ADC_StartConversion(AT91C_BASE_ADC); // start conversion
      while(!(AT91F_ADC_GetStatus(AT91C_BASE_ADC) & AT91C_ADC_EOC5)); // wait for EOC
      sum += AT91F_ADC_GetConvertedDataCH5(AT91C_BASE_ADC); // add A/D result 16 times
      Delay_ms(1);
    }
  sum >>= 4;				// divide sum by 16 for average value
  AD_data = (int)((float)sum*33./1024. + 0.5);	// voltage = 10*(sum*3.3/1024)

  n++;
  if(n == 111) n = 0;

  AD_flag = 1;
}

void GLCD_xy_temp(unsigned int x,unsigned int y) /* set character position */
{ xcharacter = x;
  ydot = y;

  GLCD_command(GLCD_CS2|GLCD_CS1, 0xB8+xcharacter); // X address

  if(ydot <= 63)				// if y <= 63, CS1 Y address
    GLCD_command(GLCD_CS1, 0x40+ydot);
  else						// if y >= 64, CS2 Y address
    GLCD_command(GLCD_CS2, 0x40+ydot-64);
}

void GLCD_English_temp(unsigned int attribute, unsigned char character)
						/* display a character */
{ unsigned int i, cs, x;

  GLCD_xy_temp(xcharacter, ydot);
  if(ydot <= 63)				// if y <= 63, CS1
    cs = GLCD_CS1;
  else						// if y >= 64, CS2
    cs = GLCD_CS2;
  for(i = 0; i <= 4; i++)
    { x = font[character-0x20][i];
      if((cursor_flag == 1) && (xcharacter == xcursor) && (ycharacter == ycursor))
        x |= 0x80;
      if(attribute == 0x01)			// reverse ?
        x = ~x;
      GLCD_data(cs, x);
    }
  x = 0x00;					// last byte of font
  if(attribute == 0x01)
    x = ~x;
  GLCD_data(cs, x);

  ydot += 6;					// go next character position
}

void GLCD_string_temp(unsigned int x, unsigned int y, unsigned int attribute, char *string)
						/* display a string */
{ xcharacter = x;
  ydot = y;

  while(*string != '\0')
     { GLCD_English_temp(attribute, *string);	// display a charcater
       string++;
     }
}

void Line_temp(int xx1, int yy1, int xx2, int yy2) /* draw a straight line */
{ int x, y;

  if(xx1 != xx2)				// if xx1 != xx2, x is variable
    { if(xx1 < xx2)				//              y is function
        for(x = xx1; x <= xx2; x++)
          { y = yy1 + (x - xx1)*(yy2 - yy1)/(xx2 - xx1);
            Dot(x,y);
          }
      else
        for(x = xx1; x >= xx2; x--)
          { y = yy1 + (x - xx1)*(yy2 - yy1)/(xx2 - xx1);
            Dot(x,y);
          }
    }
  else if(yy1 != yy2)				// if yy1 != yy2, y is variable
    { if(yy1 < yy2)				//              x is function
        for(y = yy1; y <= yy2; y++)
          { x = xx1 + (y - yy1)*(xx2 - xx1)/(yy2 - yy1);
            Dot(x,y);
          }
      else
        for(y = yy1; y >= yy2; y--)
          { x = xx1 + (y - yy1)*(xx2 - xx1)/(yy2 - yy1);
            Dot(x,y);
          }
    }
  else						// if xx1 == xx2 and yy1 == yy2,
    Dot(xx1,yy1);				//             it is a dot
}

int main(void)
{ unsigned int i, x, y, xo, yo;
  unsigned int xaxis = 10, yaxis = 53;

  MCU_initialize();				// initialize AT91SAM7S256 & kit
  Delay_ms(50);					// wait for system stabilization
  LCD_initialize();				// initialize text LCD module
  GLCD_clear();		               		// initialize GLCD screen

  LCD_string(0x80,"  Oscilloscope  ");		// display title
  LCD_string(0xC0," for VR1 Voltage");
  Beep();

  AT91F_PITC_CfgPMC();				// enable peripheral clock for PIT
  AT91F_PITInit(AT91C_BASE_PITC,1,48);		// enable and initialize PIT
  AT91F_PITSetPIV(AT91C_BASE_PITC,300000-1);	// 48MHz/16/300000 = 10Hz
  
  AT91F_PITEnableInt(AT91C_BASE_PITC);		// initialize PIT interrupt
  AT91F_AIC_ConfigureIt(AT91C_BASE_AIC,AT91C_ID_SYS,7,1,PIT_ISR);
  AT91F_AIC_EnableIt(AT91C_BASE_AIC,AT91C_ID_SYS);

  AT91F_ADC_CfgPMC();				// enable peripheral clock for ADC
  AT91F_ADC_SoftReset(AT91C_BASE_ADC);		// clear all previous ADC settings
  *AT91C_ADC_MR = 0x02020400;			// SHTIM=2, STARTUP=2, 4.8MHz, 10 bit
  AT91F_ADC_EnableChannel(AT91C_BASE_ADC, AT91C_ADC_CH5); // select CH5 for VR1

  n = 0;					// initial interrupt count
  AD_flag = 0;

  while(1)
    { Clear_screen();				// initialize GLCD screen

      Line_temp(yaxis,xaxis-1,yaxis,125);	// draw X axis
      Line_temp(yaxis-2,123,yaxis,125);
      Line_temp(yaxis+2,123,yaxis,125);
      for(y=xaxis+10; y<=xaxis+110; y += 10)
        Line_temp(yaxis-1,y,yaxis+1,y);
      for(y=xaxis, i=0; y<=xaxis+80; y += 20, i += 2)
        { GLCD_xy_temp(7, y-2);
          GLCD_English_temp(0,i+'0');
        }
      GLCD_string_temp(7,108,0,"sec");

      Line_temp(0,xaxis,yaxis+1,xaxis);		// draw Y axis
      Line_temp(2,xaxis-2,0,xaxis);
      Line_temp(2,xaxis+2,0,xaxis);
      for(x=3; x<=43; x += 10)
        Line_temp(x,xaxis-1,x,xaxis+1);
      GLCD_xy_temp(6,2); GLCD_English_temp(0,'0');
      GLCD_xy_temp(0,2); GLCD_English_temp(0,'V');

      yo = xaxis;				// initial point of old data
      xo = yaxis;

      while(n)
        { while(!AD_flag);			// wait until new A/D data
          AD_flag = 0;

	  y = xaxis + n;			// draw line from old point
	  x = yaxis - AD_data;			//           to new point
	  Line_temp(xo,yo,x,y);

	  yo = y;				// old point <-- new point
	  xo = x;
        }
    }
}