Example Code for Arduino-Touch Screen Calibration

Hardware Preparation

• 3.5 TFT Resistive Touch Shield (SKU:DFR0348) × 1, Purchase Link: https://www.dfrobot.com/product-1268.html
• Arduino Compatible Board × 1, Purchase Link: https://www.arduino.cc/en/Guide/HomePage

Software Preparation

• Arduino IDE (Latest Version), Download Link: https://www.arduino.cc/en/software
• DmTftLibrary, Download Link: https://bitbucket.org/displaymodule/dmtftlibrary/get/master.zip
• Arduino Library Installation Guide: https://docs.arduino.cc/software/ide-v1/tutorials/installing-libraries

Wiring Diagram

The 3.5 TFT Resistive Touch Shield connects directly on top of an Arduino pin compatible device (no additional wiring required).

Sample Code

 #include <SPI.h>
 #include <DmTftSsd2119.h>
 #include <DmTouch.h>
 #include <utility/DmTouchCalibration.h>
 DmTftSsd2119 tft = DmTftSsd2119();
 DmTouch dmTouch = DmTouch(DmTouch::DM_TFT35_107);
 DmTouchCalibration calibration = DmTouchCalibration(&tft, &dmTouch);
 bool calibrated = false;
 void setup() {
 dmTouch.setCalibrationMatrix(calibration.getDefaultCalibrationData((int)DmTouch::DM_TFT35_107));
 tft.init();
 dmTouch.init();
 }
 void loop()
 {
  uint16_t x, y ;
  bool touched = true;
  if (dmTouch.isTouched()) {
  dmTouch.readTouchData(x,y,touched);//x, y coordinates read contacts
  calibration.drawCalibPoint(x, y);//In a display of contact
  }
 }

Result

You can write by touching the screen.