arduino with touch screen to achieve handwrite

The LCD connection is the same as that in “ITDB02-2.4 8Bit Mode Demo“, and the touch screen connection is :

DCLK to D14(A0) pin of Arduino CS to D15(A1) pin of Arduino DIN to D16(A2) pin of Arduino
DOUT to D18(A4) pin of Arduino IRQ to D19(A5) pin of Arduino

The display code is the same as we have released , now we just give a brief introduction of SPI and touch IC control.

SPI Start:

void spistar()
{ digitalWrite(CS,HIGH); digitalWrite(DCLK,HIGH); digitalWrite(DIN,HIGH); digitalWrite(DCLK,HIGH); } SPI Write Data function:

void WriteCharTo7843(unsigned char num)
{ unsigned char count=0; unsigned char temp; unsigned nop; temp=num; digitalWrite(DCLK,LOW); for(count=0;count[HTML_REMOVED]8;count++) { if(temp[HTML_REMOVED]0x80) digitalWrite(DIN,HIGH); else digitalWrite(DIN,LOW);

temp=temp<<1; 
digitalWrite(DCLK,LOW);                
nop++;
nop++;
digitalWrite(DCLK,HIGH);
nop++;
nop++;

} } SPI Read Data function:

unsigned int ReadFromCharFrom7843()
{ unsigned nop; unsigned char count=0; unsigned int Num=0; for(count=0;count[HTML_REMOVED]12;count++) { Num[HTML_REMOVED][HTML_REMOVED]=1; digitalWrite(DCLK,HIGH);
nop++; digitalWrite(DCLK,LOW); nop++; if(digitalRead(DOUT)) Num++; } return(Num); } Get coordinates:

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); } Download the code into Arduino , and you can see the handwrite effects as the previous image shown :

Note : ITDB02 the touch and LCD is 3V3 , so if you want to use the Arduino 5V pin to connect it , reduction voltage and limiting current part is necessary .

You can find more information and whole project here: http://iteadstudio.com/application-note/itdb02-touch-screen-handwrite-demo