Series: Using the GT-SP Touch Panel TFT Display with Arduino

UI Control of GT-SP Display Using an Infrared Receiver Module

Table of Contents

DownloadDownload sample project & program (for GT Design Studio & Arduino)

Hello everyone, I’m @kissaten, a beginner in electronics. In this series, I’m explaining the process of connecting a 7-inch touch display (GT-SP series “GTWV070S3A00P”) to an Arduino and working on various projects.

In this article, we will explain the process of creating an application that controls screen transitions and the backlight brightness of the GT-SP display from a remote control using an infrared receiver module. We will also touch on troubleshooting communication conflicts when handling both infrared signal reception and display control on a single microcontroller, as well as synchronizing states with touch panel operations.

https://www.noritake-elec.com/wp/wp-content/uploads/2026/07/noritake22-4.mp4

Hardware Connection and Library Preparation

In this project, we will add a commercially available infrared receiver module and an infrared remote control to the Arduino and GT-SP display environment we have built in previous articles.

Hardware Pin Connection

This assumes the Arduino and GT-SP display are already connected via serial communication and control pins. We will connect the infrared module as an addition as follows.

[Arduino Side] [Infrared Module Side]

5V ⇔ VCC
GND ⇔ GND
Pin 11 Data ⇔ Output

Picture by [FritzingCC BY-SA)]
「KY-022 Infrared Receiver Module Fritzing Part」by [arduinomodules.infoLicense (CC BY-SA 4.0)]

Installing the Library

We will use an external library to analyze the infrared signals. From the Arduino IDE menu, open “Sketch” > “Include Library” > “Manage Libraries…”, and type “IRremote” in the search box. Find the “IRremote” library in the search results and install it.

Measurement and Confirmation of Infrared Codes

The signals transmitted when a remote control button is pressed vary depending on the remote control model. Therefore, you first need to identify the hexadecimal codes assigned to each button on the remote you are using.

Write the following infrared analysis sketch to the Arduino and open the Serial Monitor (38400bps).

#include
#include // 赤外線ライブラリ | IRremote library

// ピン接続 | Pin assign
#define IR_RECEIVE_PIN 11 // 赤外線受信ピン | IR Receiver Pin

void setup() {
// シリアル通信の開始 | Start serial communication
Serial.begin(38400); // 38400bps Baud rate

// 赤外線受信の開始 | Start the receiver
IrReceiver.begin(IR_RECEIVE_PIN, ENABLE_LED_FEEDBACK);
}

void loop() {
// 赤外線信号を受信したか判定 | Check if IR signal is received
if (IrReceiver.decode()) {

// 受信したコマンドを16進数で表示 | Print received command in HEX
Serial.print("Command: 0x");
Serial.println(IrReceiver.decodedIRData.command, HEX);

// 次の信号を受信する準備 | Receive the next value
IrReceiver.resume();
}
}

#include

#include // 赤外線ライブラリ | IRremote library

// ピン接続 | Pin assign

#define IR_RECEIVE_PIN 11 // 赤外線受信ピン | IR Receiver Pin

void setup() {

// シリアル通信の開始 | Start serial communication

Serial.begin(38400); // 38400bps Baud rate

// 赤外線受信の開始 | Start the receiver

IrReceiver.begin(IR_RECEIVE_PIN, ENABLE_LED_FEEDBACK);

}

void loop() {

// 赤外線信号を受信したか判定 | Check if IR signal is received

if (IrReceiver.decode()) {

// 受信したコマンドを16進数で表示 | Print received command in HEX

Serial.print("Command: 0x");

Serial.println(IrReceiver.decodedIRData.command, HEX);

// 次の信号を受信する準備 | Receive the next value

IrReceiver.resume();

}

When you press a button on the remote while pointing it at the receiver in this state, the code will be displayed in the Serial Monitor in a format like “Command: 0x45”.

In this sample, we will build the system by assigning the following codes to each operation based on the measurement results.
POWER Button: 0x45 Rewind (Move Left) Button: 0x44 Fast Forward (Move Right) Button: 0x43 Play (Select) Button: 0x40 VOL+ Button: 0x46 VOL- Button: 0x15 0 Button: 0x16

Application UI Design

Using GT Design Studio, we will create three screens with different purposes and assign remote control operations to each.

Page 0: HOME

A selection screen with a side-by-side menu and a cursor. Use the left and right buttons on the remote to move the cursor, and the select button to transition to the corresponding page.

Page 1: SETTING

A display brightness adjustment screen using a separate bar graph (Property ID: 0x40). The brightness can be adjusted in approximately 20% increments using the VOL+ and VOL- buttons.

Page 2: ABOUT

An explanation screen showing the system configuration, etc.

As a common operation across all screens, pressing the 0 button returns to the HOME screen, and the POWER button toggles the display on and off.

Bidirectional Synchronization with the Touch Panel

If page transitions or brightness adjustments are made via touch panel operations rather than the remote control, inconsistencies easily occur between the state variables held by the Arduino and the actual screen state.

To solve this, we set a single-character serial transmission in the touch action properties for each button in GT Design Studio as follows.

When HOME button is pressed: h
When SETTING button is pressed: s
When ABOUT button is pressed: a
When VOL+ button is pressed: u
When VOL- button is pressed: d

By having the Arduino receive these characters and update its internal variables, we achieve state synchronization between the remote control and the touch panel at a practically problem-free level, even if it is not a completely simultaneous operation.

The image above is an example of the event when the SETTING button is pressed. It sets an event that uses DATA_TX_FIX to send “s” to the Arduino and an event to jump to the SETTING page.

The image above is an example of the event when the VOL+ button is pressed. It is an event that sends “u” to the Arduino using DATA_TX_FIX. The program receives this and increases the screen brightness.

Arduino Program

This is the source code for Arduino that implements the specifications and countermeasures mentioned above. The dedicated functions for GT-SP are placed according to the specifications, and the infrared reception processing and serial reception processing are branched within the main loop.

DownloadDownload sample project & program (for GT Design Studio & Arduino)

#include <Arduino.h>
#include <IRremote.hpp> // 赤外線ライブラリ | IRremote library
#include <string.h>
 
// ピン接続 | Pin assign
#define GT_DTR 4 // DTRピン | DTR pin
#define GT_DSR 6 // DSRピン | DSR pin
#define IR_RECEIVE_PIN 11 // 赤外線受信ピン | IR Receiver Pin
 
// 変数設定 | Variable setting
int current_brightness = 255; // 明るさ現在値(0-255) | Current brightness
const int brightness_step = 51; // 変更ステップ(約20%) | Brightness step
const int min_brightness = 0; // 最小明るさ | Minimum brightness
bool is_display_on = true; // 画面表示状態 | Display power state
 
// 状態管理変数 | State management variables
int current_page = 0; // 現在のページ(0:HOME, 1:SETTING, 2:ABOUT) | Current page
int cursor_pos = 0;   // カーソル位置(0:左/SETTING, 1:右/ABOUT) | Cursor position
 
// 連続入力防止用の変数 | Variables for preventing continuous input
unsigned long last_ir_time = 0; // 前回赤外線を処理した時間 | Last IR processed time
const unsigned long IR_COOL_TIME = 200; // クールタイム(ミリ秒) | Cool time (milliseconds)
 
// GT Design Studioで設定したプロパティID | Property IDs set in GT Design Studio
const int PROP_CURSOR_X = 0x02; // カーソル(No3)のPosition X プロパティID | Position X Property ID of Cursor (No3)
const int PROP_GRAPH_VAL = 0x40; // グラフ(No8)のValue プロパティID | Value Property ID of Graph (No8)
const int PROP_TEXT_STR = 0x40; // テキスト(No9)のText プロパティID | Text Property ID of Text (No9)
 
void setup() {
  pinMode(GT_DTR, INPUT);
  pinMode(GT_DSR, OUTPUT);
  digitalWrite(GT_DSR, LOW);
 
  Serial.begin(38400); 
  Serial.setTimeout(100);
 
  IrReceiver.begin(IR_RECEIVE_PIN, ENABLE_LED_FEEDBACK);
 
  delay(1000); 
  
  // 起動時の初期輝度を設定 | Set initial brightness
  set_gtsp_brightness(current_brightness);
  
  // 初期画面をHOME(ページ0)に設定 | Set initial page to HOME
  gtsp_PgControl(0x10, 0); 
 
  // 起動時に現在の明るさをグラフとテキストに同期させておく | Sync current brightness to UI
  update_brightness(0);
}
 
void loop() {
  // 1. 赤外線リモコンからの操作処理 | 1. IR Remote operation processing
  if (IrReceiver.decode()) {
    unsigned long current_time = millis(); // 現在の時間を取得 | Get current time
 
    // クールタイムが経過しているかチェック | Check if cool time has passed
    if (current_time - last_ir_time > IR_COOL_TIME) {
      unsigned long ir_code = IrReceiver.decodedIRData.command;
      
      // 全画面共通：POWERボタン(0x45) | Common: POWER button
      if (ir_code == 0x45) {
        is_display_on = !is_display_on;
        if (is_display_on) {
          set_gtsp_brightness(current_brightness); // 復帰 | Resume
        } else {
          set_gtsp_brightness(0); // 仮の消灯処理 | Temporary turn off
        }
      }
 
      // HOME画面(Page 0)の時の操作 | Operation on HOME screen
      else if (current_page == 0) {
        if (ir_code == 0x44) { // ◀◀ 左移動 | Move Left
          cursor_pos = 0;
          gtsp_ObjPrpSet_val(3, PROP_CURSOR_X, 4, 250); 
          gtsp_PgControl(0x10, 0); // ページ0をリロードして反映させる | Reload page 0 to reflect
        } 
        else if (ir_code == 0x43) { // ▶▶ 右移動 | Move Right
          cursor_pos = 1;
          gtsp_ObjPrpSet_val(3, PROP_CURSOR_X, 4, 530); 
          gtsp_PgControl(0x10, 0); // ページ0をリロードして反映させる | Reload page 0 to reflect
        }
        else if (ir_code == 0x40) { // ▶ 決定 | Enter
          if (cursor_pos == 0) {
            current_page = 1;
            gtsp_PgControl(0x10, 1); // SETTING(ページ1)へ | Go to SETTING (Page 1)
            update_brightness(0); // 画面遷移時にグラフとテキストを同期 | Sync graph and text on page transition
          } else {
            current_page = 2;
            gtsp_PgControl(0x10, 2); // ABOUT(ページ2)へ | Go to ABOUT (Page 2)
          }
        }
      }
 
      // SETTING画面(Page 1)の時の操作 | Operation on SETTING screen
      else if (current_page == 1) {
        if (ir_code == 0x46) { // VOL+ | VOL+
          update_brightness(brightness_step);
        } 
        else if (ir_code == 0x15) { // VOL- | VOL-
          update_brightness(-brightness_step);
        }
        else if (ir_code == 0x16) { // 0ボタン | 0 button
          current_page = 0;
          gtsp_PgControl(0x10, 0); // HOMEへ戻る | Return to HOME
        }
      }
 
      // ABOUT画面(Page 2)の時の操作 | Operation on ABOUT screen
      else if (current_page == 2) {
        if (ir_code == 0x16) { // 0ボタン | 0 button
          current_page = 0;
          gtsp_PgControl(0x10, 0); // HOMEへ戻る | Return to HOME
        }
      }
 
      // 最後に処理した時間を更新 | Update last processed time
      last_ir_time = current_time; 
    }
    
    // クールタイム中であっても、受信バッファは常に空にして次の信号に備える | Always clear the receive buffer for the next signal even during cool time
    IrReceiver.resume(); 
  }
 
  // 2. 画面のタッチ操作（シリアル受信）処理 | 2. Touch operation (Serial receive) processing
  if (Serial.available() > 0) {
    char touch_cmd = Serial.read();
    
    // ページ遷移の報告を受け取って状態を同期する | Receive page transition report and sync state
    if (touch_cmd == 'h') {
      current_page = 0;
    }
    else if (touch_cmd == 's') {
      current_page = 1;
      update_brightness(0); // SETTING画面に来たので明るさUIも同期 | Sync brightness UI as it moved to SETTING screen
    }
    else if (touch_cmd == 'a') {
      current_page = 2;
    }
    
    // SETTING画面(Page 1)の時だけタッチ操作を受け付ける | Accept touch operation only on the SETTING screen (Page 1)
    if (current_page == 1) {
      if (touch_cmd == 'u') { 
        update_brightness(brightness_step); // 明るさアップ | Brightness up
      }
      else if (touch_cmd == 'd') { 
        update_brightness(-brightness_step); // 明るさダウン | Brightness down
      }
    }
  }
}
 
/********************** カスタム関数 | Custom Functions **********************/
 
void update_brightness(int change_val) {
  current_brightness = current_brightness + change_val;
  
  if (current_brightness > 255) current_brightness = 255;
  if (current_brightness < min_brightness) current_brightness = min_brightness;
 
  set_gtsp_brightness(current_brightness);
 
  int percent = (current_brightness * 100) / 255;
 
  // グラフとテキストへ送信 | Send to graph and text
  gtsp_ObjPrpSet_val(8, PROP_GRAPH_VAL, 4, percent);
  gtsp_ObjPrpSet_string(9, PROP_TEXT_STR, String(percent));
}
 
void set_gtsp_brightness(int val) {
  gt_print("CMD"); 
  gt_put(0x58);    
  gt_put(val);     
}
 
/********************** GT-SP関数 | Function for GT-SP **********************/
 
////////////////////////////////////////////////////
// オブジェクト制御コマンド - プロパティ設定 (数値用) | Object Control Command - Property Setting (for Value)
////////////////////////////////////////////////////
void gtsp_ObjPrpSet_val(int obj, int prp, int ln, unsigned long val) {
  gt_print("CMD");     // コマンドヘッダ | Command header
  gt_put(0xd3);        // オブジェクト-プロパティ設定コマンド | Object-Property Setting
  gt_put(obj >> 0);    // オブジェクトNo. 下位バイト | Object No. Lower byte
  gt_put(obj >> 8);    // オブジェクトNo. 上位バイト | Object No. Upper byte
  gt_put(prp >> 0);    // プロパティNo. 下位バイト | Property No. Lower byte
  gt_put(prp >> 8);    // プロパティNo. 上位バイト | Property No. Upper byte
  gt_put(ln >> 0);     // データ長 最下位バイト | Data length Least significant byte
  gt_put(ln >> 8);     // データ長 下位バイト | Data length second byte
  gt_put(ln >> 16);    // データ長 上位バイト | Data length third byte
  gt_put(ln >> 24);    // データ長 最上位バイト | Data length Most significant byte
  if (ln >= 1) gt_put(val >> 0);
  if (ln >= 2) gt_put(val >> 8);
  if (ln >= 3) gt_put(val >> 16);
  if (ln >= 4) gt_put(val >> 24);
}
 
////////////////////////////////////////////////////
//  オブジェクト制御コマンド - プロパティ設定 (文字列用) | Object Control Command - Property Setting (for String)
////////////////////////////////////////////////////
void gtsp_ObjPrpSet_string(int obj, int prp, String val )
{
  gt_print("CMD");     // コマンドヘッダ | Command header
  gt_put(0xd3);        // オブジェクト-プロパティ設定コマンド | Object-Property Setting
  gt_put(obj >> 0);    // オブジェクトNo. 下位バイト | Object No. Lower byte
  gt_put(obj >> 8);    // オブジェクトNo. 上位バイト | Object No. Upper byte
  gt_put(prp >> 0);    // プロパティNo. 下位バイト | Property No. Lower byte 
  gt_put(prp >> 8);    // プロパティNo. 上位バイト | Property No. Upper byte 
  gt_put(val.length() >> 0);    // データ長 最下位バイト | Data length Least significant byte
  gt_put(val.length() >> 8);    // データ長 下位バイト | Data length second byte
  gt_put(val.length() >> 16);   // データ長 上位バイト | Data length third byte
  gt_put(val.length() >> 24);   // データ長 最上位バイト | Data length Most significant byte
  gt_print(val);       // 文字列送信 | Send string
}
 
////////////////////////////////////////////////////
//  GUIページ制御/POPUP制御 | GUI PAGE/POPUP Control Command
////////////////////////////////////////////////////
void gtsp_PgControl(int typ, int pg)
{
  gt_print("CMD");     // コマンドヘッダ | Command header
  gt_put(0xfb);        // UIページ制御/POPUP制御設定コマンド | Object-Property Setting
  gt_put(typ);       // 制御タイプ | Type (10h:PAGE Select, 20h:POPUP Open, 21h, POPUP Close)
  gt_put(pg >> 0);    // PAGE No. 下位バイト | Page No. Lower byte
  gt_put(pg >> 8);    // PAGE No. 上位バイト | Page No. Upper byte
}
 
////////////////////////////////////////////////////
// 文字列送信 | Send string to GT-SP
////////////////////////////////////////////////////
void gt_print(String val) {
  int val_i;
  // 文字列を1文字ずつ送信 | Send string per one byte
  for (val_i = 0; val_i < val.length(); val_i++) {
    while (digitalRead(GT_DTR) == HIGH) {} // 処理待ち確認 | busycheck
    Serial.print(val.substring(val_i, val_i + 1));
  }
}
 
////////////////////////////////////////////////////
// 1byte送信 | Send byte to GT-SP
////////////////////////////////////////////////////
void gt_put(unsigned char onebyte) {
  while (digitalRead(GT_DTR) == HIGH) {} // 処理待ち確認 | busycheck
  Serial.write(onebyte);
}

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#include <Arduino.h>

#include <IRremote.hpp> // 赤外線ライブラリ | IRremote library

#include <string.h>

// ピン接続 | Pin assign

#define GT_DTR 4 // DTRピン | DTR pin

#define GT_DSR 6 // DSRピン | DSR pin

#define IR_RECEIVE_PIN 11 // 赤外線受信ピン | IR Receiver Pin

// 変数設定 | Variable setting

int current_brightness = 255; // 明るさ現在値(0-255) | Current brightness

const int brightness_step = 51; // 変更ステップ(約20%) | Brightness step

const int min_brightness = 0; // 最小明るさ | Minimum brightness

bool is_display_on = true; // 画面表示状態 | Display power state

// 状態管理変数 | State management variables

int current_page = 0; // 現在のページ(0:HOME, 1:SETTING, 2:ABOUT) | Current page

int cursor_pos = 0; // カーソル位置(0:左/SETTING, 1:右/ABOUT) | Cursor position

// 連続入力防止用の変数 | Variables for preventing continuous input

unsigned long last_ir_time = 0; // 前回赤外線を処理した時間 | Last IR processed time

const unsigned long IR_COOL_TIME = 200; // クールタイム(ミリ秒) | Cool time (milliseconds)

// GT Design Studioで設定したプロパティID | Property IDs set in GT Design Studio

const int PROP_CURSOR_X = 0x02; // カーソル(No3)のPosition X プロパティID | Position X Property ID of Cursor (No3)

const int PROP_GRAPH_VAL = 0x40; // グラフ(No8)のValue プロパティID | Value Property ID of Graph (No8)

const int PROP_TEXT_STR = 0x40; // テキスト(No9)のText プロパティID | Text Property ID of Text (No9)

void setup() {

pinMode(GT_DTR, INPUT);

pinMode(GT_DSR, OUTPUT);

digitalWrite(GT_DSR, LOW);

Serial.begin(38400);

Serial.setTimeout(100);

IrReceiver.begin(IR_RECEIVE_PIN, ENABLE_LED_FEEDBACK);

delay(1000);

// 起動時の初期輝度を設定 | Set initial brightness

set_gtsp_brightness(current_brightness);

// 初期画面をHOME(ページ0)に設定 | Set initial page to HOME

gtsp_PgControl(0x10, 0);

// 起動時に現在の明るさをグラフとテキストに同期させておく | Sync current brightness to UI

update_brightness(0);

}

void loop() {

// 1. 赤外線リモコンからの操作処理 | 1. IR Remote operation processing

if (IrReceiver.decode()) {

unsigned long current_time = millis(); // 現在の時間を取得 | Get current time

// クールタイムが経過しているかチェック | Check if cool time has passed

if (current_time - last_ir_time > IR_COOL_TIME) {

unsigned long ir_code = IrReceiver.decodedIRData.command;

// 全画面共通：POWERボタン(0x45) | Common: POWER button

if (ir_code == 0x45) {

is_display_on = !is_display_on;

if (is_display_on) {

set_gtsp_brightness(current_brightness); // 復帰 | Resume

} else {

set_gtsp_brightness(0); // 仮の消灯処理 | Temporary turn off

}

// HOME画面(Page 0)の時の操作 | Operation on HOME screen

else if (current_page == 0) {

if (ir_code == 0x44) { // ◀◀ 左移動 | Move Left

cursor_pos = 0;

gtsp_ObjPrpSet_val(3, PROP_CURSOR_X, 4, 250);

gtsp_PgControl(0x10, 0); // ページ0をリロードして反映させる | Reload page 0 to reflect

}

else if (ir_code == 0x43) { // ▶▶ 右移動 | Move Right

cursor_pos = 1;

gtsp_ObjPrpSet_val(3, PROP_CURSOR_X, 4, 530);

gtsp_PgControl(0x10, 0); // ページ0をリロードして反映させる | Reload page 0 to reflect

}

else if (ir_code == 0x40) { // ▶ 決定 | Enter

if (cursor_pos == 0) {

current_page = 1;

gtsp_PgControl(0x10, 1); // SETTING(ページ1)へ | Go to SETTING (Page 1)

update_brightness(0); // 画面遷移時にグラフとテキストを同期 | Sync graph and text on page transition

} else {

current_page = 2;

gtsp_PgControl(0x10, 2); // ABOUT(ページ2)へ | Go to ABOUT (Page 2)

}

// SETTING画面(Page 1)の時の操作 | Operation on SETTING screen

else if (current_page == 1) {

if (ir_code == 0x46) { // VOL+ | VOL+

update_brightness(brightness_step);

}

else if (ir_code == 0x15) { // VOL- | VOL-

update_brightness(-brightness_step);

}

else if (ir_code == 0x16) { // 0ボタン | 0 button

current_page = 0;

gtsp_PgControl(0x10, 0); // HOMEへ戻る | Return to HOME

}

// ABOUT画面(Page 2)の時の操作 | Operation on ABOUT screen

else if (current_page == 2) {

if (ir_code == 0x16) { // 0ボタン | 0 button

current_page = 0;

gtsp_PgControl(0x10, 0); // HOMEへ戻る | Return to HOME

}

// 最後に処理した時間を更新 | Update last processed time

last_ir_time = current_time;

}

// クールタイム中であっても、受信バッファは常に空にして次の信号に備える | Always clear the receive buffer for the next signal even during cool time

IrReceiver.resume();

}

// 2. 画面のタッチ操作（シリアル受信）処理 | 2. Touch operation (Serial receive) processing

if (Serial.available() > 0) {

char touch_cmd = Serial.read();

// ページ遷移の報告を受け取って状態を同期する | Receive page transition report and sync state

if (touch_cmd == 'h') {

current_page = 0;

}

else if (touch_cmd == 's') {

current_page = 1;

update_brightness(0); // SETTING画面に来たので明るさUIも同期 | Sync brightness UI as it moved to SETTING screen

}

else if (touch_cmd == 'a') {

current_page = 2;

}

// SETTING画面(Page 1)の時だけタッチ操作を受け付ける | Accept touch operation only on the SETTING screen (Page 1)

if (current_page == 1) {

if (touch_cmd == 'u') {

update_brightness(brightness_step); // 明るさアップ | Brightness up

}

else if (touch_cmd == 'd') {

update_brightness(-brightness_step); // 明るさダウン | Brightness down

}

/********************** カスタム関数 | Custom Functions **********************/

void update_brightness(int change_val) {

current_brightness = current_brightness + change_val;

if (current_brightness > 255) current_brightness = 255;

if (current_brightness < min_brightness) current_brightness = min_brightness;

set_gtsp_brightness(current_brightness);

int percent = (current_brightness * 100) / 255;

// グラフとテキストへ送信 | Send to graph and text

gtsp_ObjPrpSet_val(8, PROP_GRAPH_VAL, 4, percent);

gtsp_ObjPrpSet_string(9, PROP_TEXT_STR, String(percent));

}

void set_gtsp_brightness(int val) {

gt_print("CMD");

gt_put(0x58);

gt_put(val);

}

/********************** GT-SP関数 | Function for GT-SP **********************/

////////////////////////////////////////////////////

// オブジェクト制御コマンド - プロパティ設定 (数値用) | Object Control Command - Property Setting (for Value)

////////////////////////////////////////////////////

void gtsp_ObjPrpSet_val(int obj, int prp, int ln, unsigned long val) {

gt_print("CMD"); // コマンドヘッダ | Command header

gt_put(0xd3); // オブジェクト-プロパティ設定コマンド | Object-Property Setting

gt_put(obj >> 0); // オブジェクトNo. 下位バイト | Object No. Lower byte

gt_put(obj >> 8); // オブジェクトNo. 上位バイト | Object No. Upper byte

gt_put(prp >> 0); // プロパティNo. 下位バイト | Property No. Lower byte

gt_put(prp >> 8); // プロパティNo. 上位バイト | Property No. Upper byte

gt_put(ln >> 0); // データ長最下位バイト | Data length Least significant byte

gt_put(ln >> 8); // データ長下位バイト | Data length second byte

gt_put(ln >> 16); // データ長上位バイト | Data length third byte

gt_put(ln >> 24); // データ長最上位バイト | Data length Most significant byte

if (ln >= 1) gt_put(val >> 0);

if (ln >= 2) gt_put(val >> 8);

if (ln >= 3) gt_put(val >> 16);

if (ln >= 4) gt_put(val >> 24);

}

////////////////////////////////////////////////////

// オブジェクト制御コマンド - プロパティ設定 (文字列用) | Object Control Command - Property Setting (for String)

////////////////////////////////////////////////////

void gtsp_ObjPrpSet_string(int obj, int prp, String val )

{

gt_print("CMD"); // コマンドヘッダ | Command header

gt_put(0xd3); // オブジェクト-プロパティ設定コマンド | Object-Property Setting

gt_put(obj >> 0); // オブジェクトNo. 下位バイト | Object No. Lower byte

gt_put(obj >> 8); // オブジェクトNo. 上位バイト | Object No. Upper byte

gt_put(prp >> 0); // プロパティNo. 下位バイト | Property No. Lower byte

gt_put(prp >> 8); // プロパティNo. 上位バイト | Property No. Upper byte

gt_put(val.length() >> 0); // データ長最下位バイト | Data length Least significant byte

gt_put(val.length() >> 8); // データ長下位バイト | Data length second byte

gt_put(val.length() >> 16); // データ長上位バイト | Data length third byte

gt_put(val.length() >> 24); // データ長最上位バイト | Data length Most significant byte

gt_print(val); // 文字列送信 | Send string

}

////////////////////////////////////////////////////

// GUIページ制御/POPUP制御 | GUI PAGE/POPUP Control Command

////////////////////////////////////////////////////

void gtsp_PgControl(int typ, int pg)

{

gt_print("CMD"); // コマンドヘッダ | Command header

gt_put(0xfb); // UIページ制御/POPUP制御設定コマンド | Object-Property Setting

gt_put(typ); // 制御タイプ | Type (10h:PAGE Select, 20h:POPUP Open, 21h, POPUP Close)

gt_put(pg >> 0); // PAGE No. 下位バイト | Page No. Lower byte

gt_put(pg >> 8); // PAGE No. 上位バイト | Page No. Upper byte

}

////////////////////////////////////////////////////

// 文字列送信 | Send string to GT-SP

////////////////////////////////////////////////////

void gt_print(String val) {

int val_i;

// 文字列を1文字ずつ送信 | Send string per one byte

for (val_i = 0; val_i < val.length(); val_i++) {

while (digitalRead(GT_DTR) == HIGH) {} // 処理待ち確認 | busycheck

Serial.print(val.substring(val_i, val_i + 1));

}

////////////////////////////////////////////////////

// 1byte送信 | Send byte to GT-SP

////////////////////////////////////////////////////

void gt_put(unsigned char onebyte) {

while (digitalRead(GT_DTR) == HIGH) {} // 処理待ち確認 | busycheck

Serial.write(onebyte);

}

Mechanism of Cursor Movement

Let’s explain the operation when the left or right buttons on the remote control are pressed on the HOME screen.

Here, we use the “gtsp_ObjPrpSet_val” function to directly overwrite the X coordinate of the cursor on the screen (Object No. 3 in this case) from the Arduino.

If the left button is pressed, the X coordinate is set to 250, and if the right button is pressed, the value is set to 530. After overwriting the values, the “gtsp_PgControl” function is used to reload the page and update the screen display.

Synchronization of Display Brightness and Graph

Let’s explain the operation when the VOL+ and VOL- buttons are pressed on the SETTING screen.
Here, the “update_brightness” function is used to perform addition or subtraction on the current brightness in increments of about 20%.

The calculated brightness value (0-255) is passed to the “set_gtsp_brightness” function, and from there it reaches the display unit as the “0x58” backlight control command to change the actual brightness.

Simultaneously, the program recalculates the “What is the current brightness %?” for UI display, sends it to the graph (Object No. 8) with the “gtsp_ObjPrpSet_val” function, and rewrites the text (Object No. 9) display using the “gtsp_ObjPrpSet_string” function.

Summary

In this article, we explained the method of controlling the UI of the GT-SP display from a remote control using an Arduino and an infrared receiver module.

Communication conflict issues, which are often overlooked when linking different devices, can be avoided by reviewing the processing order on the microcontroller side. Furthermore, in systems with multiple input methods like a touch panel and a physical remote control, a design that properly centralizes state variables on the microcontroller side and synchronizes them with the display side is the key to stable operation.

If you apply this mechanism, the applications of the display will expand even further, not only for remote screen operation but also for automatic control linked with various sensors. Please try incorporating it into your actual projects.

Series: Using the GT-SP Touch Panel TFT Display with Arduino