ps2key.c

usage of graphical LCD in C (assembly)

#include <AT89S8253.H>

//declare global variables
unsigned char idata address;
unsigned char data LCDCont = 0x00; //00100000, [CS1] [CS2] [write] [command]
unsigned char cKeyStroke; // store keystroke 
unsigned char cLastKey0; // the last key stroke
unsigned char cLastKey1; // the pervious key of last key
long iTimeOutTimer = 0; //  reset, when  PS2 unpressed too long
unsigned char cKeyStrokeBitCount = 0; // counter for PS2 keystroke bits
unsigned char idata row_count = 0x01; //the row number of 8*8 LED martrix
unsigned char idata mData[] = {0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80}; // store column data for 8*8 LED martrix
// PS2 keyboard key mapping table
//0			1             2             3             4              5             6               7               8             9               A	          B             C               D             E             F//
unsigned char code cKeyChar[] = {
0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 
0x21, 0x21, 0x21, 0x21, 0x21, 0x51, 0x21, 0x21, 0x21, 0x21, 0x5A, 0x53, 0x41, 0x57, 0x21, 0x21, 
0x21, 0x43, 0x58, 0x44, 0x45, 0x21, 0x21, 0x21, 0x21, 0x2D, 0x56, 0x46, 0x54, 0x52, 0x21, 0x21, 
0x21, 0x4E, 0x42, 0x48, 0x47, 0x59, 0x21, 0x21, 0x21, 0x21, 0x4D, 0x4A, 0x55, 0x21, 0x21, 0x21, 
0x21, 0x21, 0x4B, 0x49, 0x4F, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x4C, 0x21, 0x50, 0x21, 0x21, 
0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 
0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x31, 0x21, 0x34, 0x37, 0x21, 0x21, 0x21, 
0x30, 0x2E, 0x32, 0x35, 0x36, 0x38, 0x21, 0x21, 0x21, 0x2B, 0x33, 0x2D, 0x2A, 0x39, 0x21, 0x21
};

// declare subroutin
void delay(unsigned long);
void tlcd_wc(unsigned char); // write control word to TEXT LCD
void tlcd_wd(unsigned char); // write data word to TEXT LCD
void init_timer0_m1(); // timer0 in mode1, 16bit counter

void main()
{
//=== initialize =====================
address = 0xF6;
init_timer0_m1(); // timer0, mode 1(16-bit counter) 
EX1 = 1; // Enable external interrupt 1 for PS2 keyboard
IT1 = 1; // external interrupt 1 negative edge trigger
EA = 1; // Eanble selected interrupt
TR0 = 1; // turn on Timer0, Timer0 for dot matrix LED

// test program for TEXT LCD ============================================================
tlcd_wc(0x0E); 	// TEXT LCD ON 		0000 1111, [1] [display on] [cursor on] [blinking off]
tlcd_wc(0x38);	// 2lines and 5x7	0011 1000, 001[8bit],[2 lines][5x7]xx
tlcd_wc(0x01); delay(500); 	// CLEAR display 00000001,  0000000[clear display], delay 2ms
tlcd_wc(0x02); delay(500);	//00000010,  000000[return home]0, delay 2ms

//mData[1] = 0xff;
while(1)
	{
	iTimeOutTimer ++;
	if(iTimeOutTimer >100000) // PS2 keystroke hasn't been pressed with a long time 
		{
		cKeyStrokeBitCount = 0;  
		cKeyStroke = 0x00;
		iTimeOutTimer = 0;
		}
	} // end of --- while loop


} // end of --- "main"

////== Other SUBROUTINEs start here ===================================
////==================================================================
/* Delay program */
void delay( unsigned long value)   
	{
	while(value>0) value--;
	}

/* init Timer0 mode1 (16-bit counter) , user have to turn on TR0 */
void init_timer0_m1()
	{
	TR0 = 0; // set timer_0 run control 'STOP'
	TMOD = (TMOD & 0xF0) | 0x01; //mode_1
	ET0 = 1; //set tiemr0 interrupt ON
	}	
	
/* write command word to TEXT LCD*/
void tlcd_wc(unsigned char cTempdata)
	{
	TR0=0; //temperoray stop timer0 (dot matrix LED)
	P0 = (LCDCont & 0x0F)|0x00; //CONTROL WORD=0000xxxx, [CS2] [CS1] [write] [command],
	P2 = (address & 0xF0)|0x0E;	//latch LCDCont to U20
	P2 = address; //unselect U20
	P0 = cTempdata;
	P2 = (address & 0xF0)|0x0C; 	//select (pulse trigger) TEXT LCD
	P2 = address;
	TR0=1; //resume dot matrix LED scanning
	delay(10); // for LCD requirement 46us
	}  //end of --- tlcd_wc
 
/* write data to TEXT LCD */
void tlcd_wd(unsigned char cTempdata)
	{
	//TR0=0; //temperoray stop timer0 (dot matrix LED)
	P0 = (LCDCont & 0x0F) | 0x10; //0001xxxx,  [CS2] [CS1] [write] [data]
	P2 = (address & 0xF0) | 0x0E;  // latch LCDCont to U20
	P2 = address; // unselect U20 
	P0= cTempdata;
	P2 = (address & 0xF0) | 0x0C; //select TEXT LCD
	P2 = address; //  unselect (pulse trigger)TEXT LCD
	//TR0=1; //resume dot matrix LED scanning
	delay(10); // for LCD requirement 46us
	} // end of  ---- tlcd_wd
	
//=== Interrupt subroutine start here=========================
// interrupt routine for PS2 keyboard, (interrupt 2)
void PS2() interrupt 2 using 1 
	{
	cKeyStrokeBitCount ++;
	if (cKeyStrokeBitCount==1) 
		{
		cKeyStroke= 0x00;
		P1_0 =1;		
		}
	else
		{
		if (P3_4 == 1) //if the bit of keystroke is '1'
			{
			switch(cKeyStrokeBitCount) //LSB first
				{
				case 2: cKeyStroke = cKeyStroke | 0x01;  break; 
				case 3: cKeyStroke = cKeyStroke | 0x02;  break;
				case 4: cKeyStroke = cKeyStroke | 0x04;  break;
				case 5: cKeyStroke = cKeyStroke | 0x08;  break;
				case 6: cKeyStroke = cKeyStroke | 0x10;  break;
				case 7: cKeyStroke = cKeyStroke | 0x20;  break;
				case 8: cKeyStroke = cKeyStroke | 0x40;  break;
				case 9: cKeyStroke = cKeyStroke | 0x80;  break;																					
				}
			if (cKeyStrokeBitCount >10) //end of get  key
				{
				cKeyStrokeBitCount = 0; // reset the keystroke counter
				iTimeOutTimer = 0; // reset time out counter
				if ((cKeyStroke != 0xF0) & (cLastKey0!= 0xF0) & cKeyStroke<0x7F) //0xF0 means release a key
					{
					tlcd_wd(cKeyChar[cKeyStroke]);
					} 
				mData[0] =  cKeyStroke;
				cLastKey1 = cLastKey0;
				cLastKey0 = cKeyStroke;
				}
			}
		}
	} /* end of ----interrupt routine for PS2 keyboard, (interrupt 2) */
	
void timer0() interrupt 1 using 1 
	{
	TR0 = 0; // temporary suspend timer0, and restore data
	row_count++;
	if (row_count==8) row_count=0;
	P0 = mData[row_count] ; //put data to matrix column
	P2 = (address & 0xF8) | 0x0D; // select matrix column
	P2 = address; // unselect matrix column and restore default address bus value
	P0 = row_count | LCDCont; //put dat to matrix row	
	P2 = (address & 0xF8) | 0x0E; // select matrix row
	P2 = address; // unselect matrix row and restore default address bus value
	TL0=0; //reload counter for next row
	TH0=240; //margin value is 235
	TF0=0;  // clear the flag of  timer0 overflow
	TR0 = 1; // resume timer0 for counting
	} /* end of ----interrupt routine for timer 0, (8x8 Dot matrix LED) */
	
// <<<<<< end of "Interrupt subroutine"	
//end  of program