Here's a sketch for using a 2.4'' touchscreen without any library. This is necessary since the Utouch-lib needs the IRQ-pin which isn't provided on some shields: here PIN 10 uses the CS-signal. Remember to check, which minimal x- any y-values your screen provides on 'touch'-events (see code remarks below):
#define LCD_RS 19
#define LCD_WR 18
#define LCD_CS 17
#define LCD_REST 16
#define DCLK 15
#define DIN 14
#define CS 10
#define DOUT 8
//#define IRQ 7
unsigned int TP_X,TP_Y,x0,y0;
unsigned int l3=0;
int lx,ly, l2, ry,rx,x3=65,y3=318;
int k=3, vh2=0x84,vl2=0xFF;
void spistar() //SPI Start
{
digitalWrite(CS,LOW);
digitalWrite(DCLK,HIGH);
digitalWrite(DIN,HIGH);
digitalWrite(DCLK,HIGH);
}
//**********************************************************
void WriteCharTo7843(unsigned char num) //SPI Write Data - works also with TCS2046
{
unsigned char count=0;
unsigned char temp;
unsigned nop;
temp=num;
digitalWrite(DCLK,LOW);
for(count=0;count<8;count++)
{
if(temp&0x80)
digitalWrite(DIN,HIGH);
else
digitalWrite(DIN,LOW);
temp=temp<<1;
digitalWrite(DCLK,LOW);
nop++;
nop++;
digitalWrite(DCLK,HIGH);
nop++;
nop++;
}
}
//**********************************************************
unsigned int ReadFromCharFrom7843() //SPI Read Data
{
unsigned nop;
unsigned char count=0;
unsigned int Num=0;
for(count=0;count<12;count++)
{
Num<<=1;
digitalWrite(DCLK,HIGH);//DCLK=1; _nop_();_nop_();_nop_();
nop++;
digitalWrite(DCLK,LOW);//DCLK=0; _nop_();_nop_();_nop_();
nop++;
if(digitalRead(DOUT)) Num++;
}
return(Num);
}
void LCD_Writ_Bus(char VH,char VL)
{
PORTD = VH;
digitalWrite(LCD_WR,LOW);
digitalWrite(LCD_WR,HIGH);
PORTD = VL;
digitalWrite(LCD_WR,LOW);
digitalWrite(LCD_WR,HIGH);
}
void LCD_Write_COM(char VH,char VL)
{
digitalWrite(LCD_RS,LOW);
LCD_Writ_Bus(VH,VL);
}
void LCD_Write_DATA(char VH,char VL)
{
digitalWrite(LCD_RS,HIGH);
LCD_Writ_Bus(VH,VL);
}
void Lcd_Write_Com_Data(int com,int val)
{
LCD_Write_COM(com>>8,com);
LCD_Write_DATA(val>>8,val);
}
void Address_set(unsigned int x1,unsigned int y1,unsigned int x2,unsigned int y2)
{
LCD_Write_COM(0x00,0x46);LCD_Write_DATA(x2,x1);
LCD_Write_COM(0x00,0x47);LCD_Write_DATA(y2>>8,y2);
LCD_Write_COM(0x00,0x48);LCD_Write_DATA(y1>>8,y1);
LCD_Write_COM(0x00,0x20);LCD_Write_DATA(x1>>8,x1);
LCD_Write_COM(0x00,0x21);LCD_Write_DATA(y1>>8,y1);
LCD_Write_COM(0x00,0x22);
}
void LCD_Init(void)
{
digitalWrite(LCD_REST,HIGH);
delay(5);
digitalWrite(LCD_REST,LOW);
delay(5);
digitalWrite(LCD_REST,HIGH);
delay(5);
digitalWrite(LCD_CS,LOW);
Lcd_Write_Com_Data(0x11,0x2004);
Lcd_Write_Com_Data(0x13,0xCC00);
Lcd_Write_Com_Data(0x15,0x2600);
Lcd_Write_Com_Data(0x14,0x252A);
Lcd_Write_Com_Data(0x12,0x0033);
Lcd_Write_Com_Data(0x13,0xCC04);
delay(1);
Lcd_Write_Com_Data(0x13,0xCC06);
delay(1);
Lcd_Write_Com_Data(0x13,0xCC4F);
delay(1);
Lcd_Write_Com_Data(0x13,0x674F);
Lcd_Write_Com_Data(0x11,0x2003);
delay(1);
Lcd_Write_Com_Data(0x30,0x2609);
Lcd_Write_Com_Data(0x31,0x242C);
Lcd_Write_Com_Data(0x32,0x1F23);
Lcd_Write_Com_Data(0x33,0x2425);
Lcd_Write_Com_Data(0x34,0x2226);
Lcd_Write_Com_Data(0x35,0x2523);
Lcd_Write_Com_Data(0x36,0x1C1A);
Lcd_Write_Com_Data(0x37,0x131D);
Lcd_Write_Com_Data(0x38,0x0B11);
Lcd_Write_Com_Data(0x39,0x1210);
Lcd_Write_Com_Data(0x3A,0x1315);
Lcd_Write_Com_Data(0x3B,0x3619);
Lcd_Write_Com_Data(0x3C,0x0D00);
Lcd_Write_Com_Data(0x3D,0x000D);
Lcd_Write_Com_Data(0x16,0x0007);
Lcd_Write_Com_Data(0x02,0x0013);
Lcd_Write_Com_Data(0x03,0x0003);
Lcd_Write_Com_Data(0x01,0x0127);
delay(1);
Lcd_Write_Com_Data(0x08,0x0303);
Lcd_Write_Com_Data(0x0A,0x000B);
Lcd_Write_Com_Data(0x0B,0x0003);
Lcd_Write_Com_Data(0x0C,0x0000);
Lcd_Write_Com_Data(0x41,0x0000);
Lcd_Write_Com_Data(0x50,0x0000);
Lcd_Write_Com_Data(0x60,0x0005);
Lcd_Write_Com_Data(0x70,0x000B);
Lcd_Write_Com_Data(0x71,0x0000);
Lcd_Write_Com_Data(0x78,0x0000);
Lcd_Write_Com_Data(0x7A,0x0000);
Lcd_Write_Com_Data(0x79,0x0007);
Lcd_Write_Com_Data(0x07,0x0051);
delay(1);
Lcd_Write_Com_Data(0x07,0x0053);
Lcd_Write_Com_Data(0x79,0x0000);
LCD_Write_COM(0x00,0x22);
digitalWrite(LCD_CS,HIGH);
}
void Pant(char VH,char VL)
{
int i,j;
Address_set(0,0,240,320);
for(i=0;i<=320;i++)
{
for (j=0;j<=240;j++)
{
LCD_Write_DATA(VH,VL);
}
}
}
void digi(int z3) //print digits indicating the color-code (2 x 0-255) to paint (increased on touch)
{
unsigned char p;
int x2, y2, z2, i,h2=1000;
digitalWrite(LCD_CS,LOW);
for(i=0;i<3;i++)
{
y2=y3;
x2=x3+(10*i);
Address_set(x2+6,y2-15,x2+7,y2);
for(p=0; p<32; p++) LCD_Write_DATA(0xFF,0xFF);
Address_set(x2,y2-15,x2+7,y2-14);
for(p=0; p<16; p++) LCD_Write_DATA(0xFF,0xFF);
Address_set(x2,y2-1,x2+7,y2);
for(p=0; p<16; p++) LCD_Write_DATA(0xFF,0xFF);
Address_set(x2,y2-8,x2+7,y2-7);
for(p=0; p<16; p++) LCD_Write_DATA(0xFF,0xFF);
Address_set(x2,y2-15,x2+1,y2);
for(p=0; p<32; p++) LCD_Write_DATA(0xFF,0xFF);
h2=h2/10;
z2=z3/h2;
z3=z3-z2*h2;
if (z2==0) {
Address_set(x2+2,y2-8,x2+5,y2-7);
for(p=0; p<8; p++) LCD_Write_DATA(0x00,0x00);
}
if (z2==1) {
Address_set(x2,y2-15,x2+5,y2);
for(p=0; p<96; p++) LCD_Write_DATA(0x00,0x00);
}
if (z2==2) {
Address_set(x2,y2-13,x2+1,y2-9);
for(p=0; p<10; p++) LCD_Write_DATA(0x00,0x00);
Address_set(x2+6,y2-6,x2+7,y2-2);
for(p=0; p<10; p++) LCD_Write_DATA(0x00,0x00);
}
if (z2==3) {
Address_set(x2,y2-13,x2+1,y2-9);
for(p=0; p<10; p++) LCD_Write_DATA(0x00,0x00);
Address_set(x2,y2-6,x2+1,y2-2);
for(p=0; p<10; p++) LCD_Write_DATA(0x00,0x00);
}
if (z2==4) {
Address_set(x2,y2-6,x2+5,y2);
for(p=0; p<42; p++) LCD_Write_DATA(0x00,0x00);
Address_set(x2+2,y2-15,x2+5,y2-14);
for(p=0; p<8; p++) LCD_Write_DATA(0x00,0x00);
}
if (z2==5) {
Address_set(x2+6,y2-13,x2+7,y2-9);
for(p=0; p<10; p++) LCD_Write_DATA(0x00,0x00);
Address_set(x2,y2-6,x2+1,y2-2);
for(p=0; p<10; p++) LCD_Write_DATA(0x00,0x00);
}
if (z2==6) {
Address_set(x2+6,y2-13,x2+7,y2-9);
for(p=0; p<10; p++) LCD_Write_DATA(0x00,0x00);
}
if (z2==7) {
Address_set(x2,y2-13,x2+5,y2);
for(p=0; p<84; p++) LCD_Write_DATA(0x00,0x00);
}
if (z2==9) {
Address_set(x2,y2-6,x2+1,y2-2);
for(p=0; p<10; p++) LCD_Write_DATA(0x00,0x00);
}
}
digitalWrite(LCD_CS,HIGH);
}
void newpa(void) //paint the frame
{
unsigned char p;
digitalWrite(LCD_CS,LOW);
Pant(0x00,0x00);
Address_set(0,319,240,319);
for(p=0; p<240; p++) LCD_Write_DATA(0xF8,0x00);
Address_set(0,0,240,0);
for(p=0; p<240; p++) LCD_Write_DATA(0xFF,0xFF);
Address_set(0,300,240,300);
for(p=0; p<240; p++) LCD_Write_DATA(0xFF,0xFF);
Address_set(0,0,0,255);
for(p=0; p<255; p++) LCD_Write_DATA(0xF8,0x00);
Address_set(0,255,0,300);
for(p=0; p<45; p++) LCD_Write_DATA(0xF8,0x00);
Address_set(239,0,239,255);
for(p=0; p<255; p++) LCD_Write_DATA(0xF8,0x00);
Address_set(239,255,239,300);
for(p=0; p<45; p++) LCD_Write_DATA(0xF8,0x00);
Address_set(50,308,59,311);
for(p=0; p<40; p++) LCD_Write_DATA(0x07,0xE0);
Address_set(53,305,56,314);
for(p=0; p<40; p++) LCD_Write_DATA(0x07,0xE0);
Address_set(215,305,239,314);
for(p=0; p<250; p++) LCD_Write_DATA(0xF8,0x00);
digitalWrite(LCD_CS,HIGH);
}
void recan(void) //status bar for painting size and example of selected color
{
int i,j;
digitalWrite(LCD_CS,LOW);
for(i=0;i<7;i++)
{
Address_set(i*5,305,i*5+3,314);
for(j=0; j<40; j++)
{
if (1+i*2<= k) LCD_Write_DATA(0xFF,0xE0); else LCD_Write_DATA(0x00,0x00);
}
}
Address_set(100,305,124,314);
for(i=0; i<250; i++) LCD_Write_DATA(vh2,vl2);
Address_set(125,305,149,314);
for(i=0; i<250; i++) LCD_Write_DATA(vh2,vl2);
digitalWrite(LCD_CS,HIGH);
}
void AD7843(void)
{
digitalWrite(CS,LOW);
WriteCharTo7843(0x90);
digitalWrite(DCLK,HIGH);
digitalWrite(DCLK,LOW);
TP_Y=ReadFromCharFrom7843();
WriteCharTo7843(0xD0);
digitalWrite(DCLK,HIGH);
digitalWrite(DCLK,LOW);
TP_X=ReadFromCharFrom7843();
digitalWrite(CS,HIGH);
}
void setup()
{
unsigned char p;
for(p=0;p<20;p++)
{
pinMode(p,OUTPUT);
}
pinMode(DOUT,INPUT);
x0=1;
y0=1;
LCD_Init();
newpa();
recan();
digi(vh2);
x3=x3+90;
digi(vl2);
spistar();
}
void loop()
{
rx=0;
ry=0;
for(l3=0;l3<8;l3++) //check touch coordinates 8 times to get a good average, skip counting if a zero value is found (prevents noise)
{
AD7843();
lx=0;
ly=-1*TP_Y;
ly=4095+ly; //4095= zero y-Signal
if(ly > 0) lx=1*TP_X; else {lx=0;ly=0;rx=0;ry=0;l3=9; }
rx=rx+lx;
ry=ry+ly;
}
lx=(rx/8-180)/15; //180= minimal x-value for touch-event
ly=(ry/8-240)/11; //240= minimal (> 4095) value for touch-event
if(ly < 1) {lx=0;ly=0; }
if(lx < 1) lx=0;
if(ly > 309-k)
{
ly=0;
if(lx > 200) k=k-2; else if (lx > 160) k=k+2;else
if (lx > 100) vh2++; else if (lx > 40) vl2++; else newpa();
lx=0;
if (k<1) k=1;
if (k>13) k=13;
if (vh2>255) vh2=0;
if (vl2>255) vl2=0;
x3=65;
digi(vh2);
x3=x3+90;
digi(vl2);
recan();
}
if(ly > 299-k) ly=299-k;
if(ly > 0)
{
x0=240-lx;
if(x0 > 240-k) x0=240-k;
y0=ly;
l2=(k+1)*(k+1);
digitalWrite(LCD_CS,LOW);
Address_set(x0,y0,x0+k,y0+k);
for (l3=0; l3<l2; l3++) LCD_Write_DATA(vh2,vl2);
digitalWrite(LCD_CS,HIGH);
}
delay (50);
}