We will be having Diwali Festival holidays from 18th October to 24th October. Any orders placed during that time will ship from 25th October onwards. Good Wishes for a joyous Diwali and a Happy New Year with plenty of Peace and Prosperity.
SUNROM ELECTRONICS

Touch Screen, 2.8 inch + Serial Output

Decoder outputs touch coordinates at 9600 baud rate

Touch Screen, 2.8 inch + Serial Output

Sunrom Part# 1255

Available We dispatch same day if ordered by 4PM (excluding holidays), then courier usually takes 2-5 days.
Quantity Pricing
Quantity :
Price (Discount%)
1-4 :
Rs.890/- (0%)
5-9 :
Rs.863/- (3%)
10-24 :
Rs.828/- (7%)
25-49 :
Rs.801/- (10%)
50-74 :
Rs.783/- (12%)
75-99 :
Rs.757/- (15%)
100-249 :
Rs.730/- (18%)
250-499 :
Rs.712/- (20%)
500-999 :
Rs.694/- (22%)
1000+ :
Rs.668/- (25%)

Downloads

Terminal-PC

This product is a combination of resistive touch screen and a controller which decodes the cordinates and output as serial data at 9600 bps. The data can be fed to any controller or passed to PC to view and further development. This resistive touch screen can be used with a stylus or fingertip and is easy to use with a microcontroller. You can put it over a paper overlay for a touch control panel or attach it to an LCD to DIY a touch-activated display.

Touch Screen Specifications

  • 2.2" x 2.75" (55mm x 70mm) overall dimensions, 1.5mm thick
  • 3.2" diagonal active area, 80mm
  • Adhesive backing to attach easily to LCDs
  • Serial output at 9600 bps, X, Y & Z co-ordinates with LED indication

Electrical Specifications

Name

Typ

Unit

Working Voltage

3-5

V DC Regulated

Output Reading Rate Every

50

Mili Seconds

Data Format (Fixed Length)

22

Byte ASCII

UART baud rate (8 bit data, no parity, 1 stop bit)

9600

bps


Use any microcontroller with RX pin to receive the data from controller or read serial data on PC and develop application.

Pinouts

Pin

Pin Name

Details

TX-O

Transmit Output

Output serial data of 3-5V logic level, Usually connected to RXD pin of microcontrollers/PC/RS232. Note: Do not connect this pin to direct PC serial port without MAX232. It will damage the module since direct PC serial port has +12V voltage level.

+3-5V

Power Supply

Regulated 3V or 5V supply input or any voltage in between.

GND

Ground

Ground level of power supply. Must be common ground with microcontroller.

Data Format

The output of data from sensor is in 22 bytes fixed length ASCII characters. The baud rate of output is 9600 bps. It output X, Y and Z values. The XY are cordinates of touch and Z is pressure value.

Example output string on screen would be strings like below,

X:0065 Y:0089 Z:0029

X:0066 Y:0089 Z:0030

X:0066 Y:0089 Z:0030

X:0062 Y:0090 Z:0026

Count->

22

21

20

19

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

 

Start

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

End

ASCII->

 

X

:

0-9

0-9

0-9

0-9

‘ ‘

Y

:

0-9

0-9

0-9

0-9

‘ ‘

Z

:

0-9

0-9

0-9

0-9

 

Fixed HEX ->

0x0A

0x58

0x3A

Value of X in 4 digits

0x20

0x59

0x3A

Value of Y in 4 digits

0x20

0x5A

0x3A

Value of Z in 4 digits

0x0D

The string starts with 0x0A which is new line as well as start of string idenfier. The string ends with 0x0D which is acting as line feed character or End of string idenfier.

Terminal software

We recommend this Terminal software which can be used receive serial data for testing purpose on PC side.

Interfacing with Microcontrollers

Just connect board output to MCU's RXD pin.

Following code is C language to decode incoming serial data and covert to Integers.   

// Compiler: Keil, Processor any 8051 core
#include <REGX51.H> // standard 8051 defines
// -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
// -=-=-=-=- Hardware Defines -=-=-=-=-=-=-=
// -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
 
char sbuffer[30], ch;
unsigned char pos;

unsigned int Xval;
unsigned  int  Yval;
unsigned  int  Zval;
 
//receive serial character from serial port
char mygetchar(void)
{
    char c;
    while(!RI);
    RI =0;
    c = SBUF;
    return SBUF;
}
 
// -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
// -=-=-=-=- Main Program -=-=-=-=-=-=-=
// -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
void main()
{
    // -=-=- Intialize variables -=-=-=
    pos = 0;
         
    // -=-=- Intialise Serial Port -=-=-=
    //Sets up MCU to use 9600 bps @ 11.059 MHz Crystal
    SCON = 0x52; // 8-bit UART mode
    TMOD = 0x20; // timer 1 mode 2 auto reload
    TH1= 0xfd; // 9600 8-n-1
    TR1 = 1; // run timer1
     
    // -=-=- Program Loop -=-=-=
    while(1)
    {
                ch = mygetchar(); //loop till character received
                if(ch==0x0D) // if received character is <CR>, 0x0D, 13 then process buffer
                {
                    pos = 0; // buffer position reset for next reading
                     
                    // extract data from serial buffer to 8 bit value
                    // convert data from ASCII to decimal
                    Xval = ((sbuffer[3]-'0')*1000) + (sbuffer[4]-'0')*100) + ((sbuffer[5]-'0')*10) +(sbuffer[6]-'0');
                    Yval = ((sbuffer[10]-'0')*1000) + (sbuffer[11]-'0')*100) + ((sbuffer[12]-'0')*10) +(sbuffer[13]-'0');
                    Zval = ((sbuffer[17]-'0')*1000) + (sbuffer[18]-'0')*100) + ((sbuffer[19]-'0')*10) +(sbuffer[20]-'0');

                    // Do whatever you wish to do with this integer variables
                    // Show on LCD or Do some action as per your application
                    // Value of sensor will be between 0-1024 (10 bit value)
                    // You can do something like below
                        //if(Xval > 100)
                        //  RELAY = 1
                                         
                } else { //store serial data to buffer
                    sbuffer[pos] = ch;
                    pos++;
                }
       } // end while
}// end main


Bestselling Products

Sunrom Electronics & Sunrom Technologies are two companies, that are the foremost online e-commerce stores since 2004, providing innovative embedded systems, components & services. Our aim is to empower you to Make In India. We work closely with electronics manufacturing companies & individuals to understand & solve the challenges faced during production. We do not just sell things, We use them ourselves in our products, and provide you with high quality tested components for trouble free experience.

Sunrom Electronics GSTIN: 24AFBPT4632H1ZJ
Handles Online Payment by CCAvenue
Sunrom Technologies GSTIN: 24AJLPP4029L1ZW
Handles Offline Bank Payments / NEFT / P.O. / Telr