TFT SENSOR

 This display module is a transmissive type color active matrix TFT(Thin Film Transistor) liquid crystal display (LCD) that uses amorphous silicon TFT as a switching device. This module is composed of a TFT LCD module, a driver circuit, and a back-light unit. The resolution of a 2.4” contains 240(RGB)X320 dots and can display up to 262k colors.

Working Principle:

TFT stands for ‘Thin Film Transistor’ and describes the control elements that actively control the individual pixels. For this reason, one speaks of so-called ‘active matrix TFTs’.

 The basic principle is quite simple: a panel with many pixels is used whereby each pixel can emit any color. To this purpose, a back light is used which is normally comprised of a number of flourescent tubes. In order to light a single pixel, all that needs to be done is for a small ‘door’ or ‘shutter’ to open to let the light pass through. The technology that makes this possible is of course more complicated and involved than the simple explanation above.

LCD (Liquid Crystal Display)

Monitors that are based on liquid crystals. Liquid crystals can change their molecular structure and therefore allow varying levels of light to pass through them (or they can block the light). Two polarizer filters, color filters and two alignment layers determine exactly how much light is allowed to pass and which colors are created. The layers are positioned between the two glass panels. A specific voltage is applied to the alignment layer, creating an electric field – which then aligns the liquid crystals. Each dot on the screen (pixel) therefore requires three components, one for red, green and blue – just as for the tubes within cathode ray tube devices.

 

Features

  1. 2.4” (diagonal), 240xRGBx320
  2. Transmissive/Normally White TFT module
  3. Viewing Direction: 12 o’clock
  4. Driving IC: ST7789V or equivalent
  5. 8/9/16/18 bit MCU, 3/4 wire SPI, 16/18 bit RGB interface options

 

Specifications

Digital supply voltage            2.4 to 4.2 V

Outline dimensions               42.72(W) x 60.26(H) x 3.8(D)

                                                (Exclude FPC, cables of backlight) mm

View area                               38.32(W) x 50.56(H) mm

Driver element                       TFT Active Matrix

Pixel arrangement                 RGB Vertical Stripe

Link to data sheet:

  1. https://cdn-learn.adafruit.com/downloads/pdf/adafruit-2-4-color-tft-touchscreen-breakout.pdf
  2. http://www.inteltronicinc.com/files/DRIVER/201411040007381.pdf

3.https://www.alliedelec.com/m/d/0f26d0930e125475349b3d3b8ac79add.pdf

 

 

Do’s and dont’s:

  1. Do check the connections before powering it up.
  2. Do hold the sensor from sides only.
  3. Do read the specifications before using the sensor.
  4. Do not touch circuit elements from finger tips, the static energy from your fingers can damage the sensor.
  5. Do not short the pins while soldering.

 

Storing Instructions:

Store in a closed container away from sunlight and water.

 

Advantages:

  1. The first advantage of screens LCD/TFT is the gain of place they allow.
  2. The TFT displays unlike tiles sparkle shiny does not and therefore offer a high degree of visual comfort.
  3. The image remains perfectly stable and clear.
  4. The life of this type of screen is important and their low power consumption.
  5. The heat release is very lower than that of conventional CRT screens, of the same electromagnetic emissions are reduced and the visual fatigue decreased.

 

Disadvantages:

  1. The brightness may prove inadequate in certain specific uses
  2. The very high resolutions are not as readily available for professional applications.
  3. The cost, which tends to decrease a little more each day, however, is not negligible.
  4. The colors are not always correctly transcribed.

 

Schematics:

 

Connections with Arduino:

 

Arduino Code:

#include <UTFT.h>

  • #include <URTouch.h>
  • //==== Creating Objects
  • UTFT myGLCD(SSD1289,38,39,40,41); //Parameters should be adjusted to your Display/Schield model
  • URTouch myTouch( 6, 5, 4, 3, 2);
  • //==== Defining Variables
  • extern uint8_t SmallFont[];
  • extern uint8_t BigFont[];
  • extern uint8_t SevenSegNumFont[];
  • extern unsigned int bird01[0x41A];
  • int x, y;
  • char currentPage, selectedUnit;
  • //Ultrasonic Sensor
  • const int VCC = 13;
  • const int trigPin = 11;
  • const int echoPin = 12;
  • long duration;
  • int distanceInch, distanceCm;
  • // RGB LEDs
  • const int redLed = 10;
  • const int greenLed = 9;
  • const int blueLed = 8;
  • int xR=38;
  • int xG=38;
  • int xB=38;
  • // Floppy Bird
  • int xP = 319;
  • int yP = 100;
  • int yB = 30;
  • int fallRateInt = 0;
  • float fallRate =0;
  • int score=0;
  • const int button = 14;
  • int buttonState = 0;
  • void setup() {
  • // Initial setup
  • InitLCD();
  • clrScr();
  • InitTouch();
  • setPrecision(PREC_MEDIUM);
  • // Defining Pin Modes
  • pinMode(VCC, OUTPUT); // VCC
  • pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
  • pinMode(echoPin, INPUT); // Sets the echoPin as an Input
  • pinMode(redLed, OUTPUT);
  • pinMode(greenLed, OUTPUT);
  • pinMode(blueLed, OUTPUT);
  • pinMode(button, INPUT);
  • digitalWrite(VCC, HIGH); // +5V – Pin 13 as VCC
  • drawHomeScreen(); // Draws the Home Screen
  • currentPage = ‘0’; // Indicates that we are at Home Screen
  • selectedUnit = ‘0’; // Indicates the selected unit for the first example, cms or inches
  • }

 

 

 

Applications:

  1. In TFT LCDs, an implementation of LCD technology.
  2. TFT panels are frequently used in digital radiography applications in general radiography.

A TFT is used in both direct and indirect capture as a base for the image receptor in medical radiography.

 

FAQ’s:

Q1. Is it compatible with Raspberry pi?

Ans. Yes.

Q2. Can we draw animations on it?

Ans. Yes, you can draw free hand figures as well as animation using the commands for TFT.

 

Referral Links:

 

  1. https://evive.cc/tutorial/arduino/arduino-tutorials-beginners/tft-hello/

2.http://www.instructables.com/id/Arduino-Touch-Screen-TFT-LCD-Tutorial-First-Review/

3.https://circuitdigest.com/microcontroller-projects/arduino-tft-lcd-interfacing-tutorial 

 

Documentation links :

  1. https://howtomechatronics.com/tutorials/arduino/arduino-tft-lcd-touch-screen-tutorial/
  1. https://www.tomshardware.com/reviews/tft-guide,114-4.html
  2. https://en.wikipedia.org/wiki/Thin-film_transistor#Applications
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