rLovyanGFXEx ESP32

B4R Library rLovyanGFXEx ESP32

Purpose
rLovyanGFXEx is an open source SPI LCD graphics library for selected displays controlled by an ESP32.

Information

This library is partial wrapped (functions to set text, draw basic shapes and colors) from the LovyanGFX library.
Enhanced with additional colors, fonts and many functions to set text, the RGB LED and more.
24-bit color codes; selected fonts like Font0 [Default], FREEMONO_12, FREESANS_12, TOMTHUMB_1, FREESERIF_12 and more.
Touch is enabled (depends on the display).
Library developed in Arduino C++.
Software: B4R 4.00 (64 bit), arduino-cli 1.2.2, ESP32 library 3.2.0, LovyanGFX 1.2.7.
Hardware: Tested with following displays:
- Sunton ESP32 2.8" TFT, w320xh240, touch, driver ILI9341.
- SSD1306 0.96" OLED, I2C w128xh64, monochrome, no touch, pins SCL 22, SDA 21, I2C address 0x3C.
- SH1106 1.3" OLED, I2C w128xh64, monochrome, no touch, pins SCL 22, SDA 21, I2C address 0x3C.
- diymore ESP32-WROOM-32 0.96" OLED, w128xh64, no touch, pins SCL 22, SDA 21, I2C address 0x3C.
- ESP32 WIFIKITV3 SSD1306 0.96" OLED , I2C, w128xh64, no touch, pins SCL 18, SDA 17, PWR 21, I2C address 0x3C.
ESP32 communicates with the TFT Display and Touchscreen using SPI communication protocol.
Not wrapped are the classes Sprites (LGFX_Sprite), Buttons (LGFX_Button) [not planned to wrap].
This library has been developed for personal use only.

Notes
The background to develop this library, is using a small TFT display as a Solar Info Panel (multi pages touch panel) for the production@home, but of course there are many other use cases.
This library is a further development of the rESP3228CYD library.

Screenshots for some of the examples

Files
rLovyanGFXEx-NNN.zip archive contains the library and sample projects.

Install
In the Arduino IDE install the library LovyanGFX - TFT LCD Graphics driver.
From the zip archive rLovyanGFXEx-NNN.zip, copy the content of the library folder, to the B4R additional libraries folder keeping the folder structure.

Display Driver
The library includes three display drivers, which are defined in the header files ESP32_2432S028.h, ESP32_SSD1306.h, ESP32_SSD1306_WIFIKITV3.h and ESP32_SH110x. Make changes as required (see source comments).

In the B4R code, the display driver must be defined (mandatory) using the Project Attribute #DefineExtra.

Sunton ESP32 = #define ESP32_2432S028
SSD1306 = #define ESP32_SSD1306
SH1106 = #define ESP32_SH110x
DIYMOREESP32OLED = #define ESP32_SSD1306
ESP32_SSD1306_WIFIKITV3.h = #define ESP32_SSD1306_WIFIKITV3

Examples setting the display driver in B4R code for the SSD1306:

C++: Copy

#Region Project Attributes
    #DefineExtra: #define ESP32_SSD1306
#End Region

Functions
See the folder examples, but also the chapter Get Started below.
The folder examples has sub-folders depending the display used: CYD2432S028, DIYMOREESP32OLED, SH110X, SSD1306, SSD1306WIFIKITV3.
Most of the examples are for the CYD2432S028 display.
For the SH110x, SSD1306, SSD1306WIFIKITV3 the examples are just the classic Hello World.
For the DIYMOREESP32OLED. there is an example using the 7-Segment-Font to display a number (max 9999).

Examples CYD2432S028

HelloWorld-InlineC - Use the native LovyanGFX library with B4R Inline C. To explore how to use the library prior wrapping.
Touch-InlineC - As previous.
Touch-InlineC-CallSub - As previous.
HelloWorld - The classic starter.
Basic - Show some of the basic functions (see below source).
Touch - Touch the display and show the touch x,y position.
Button - Create buttons and showinfo when touched.
Fonts - List the various fonts, like DEFAULT, FREEMONO_12, FREESANS_12, TOMTHUMB_1, FREESERIF_12, ORBITRON_LIGHT_24 (my fav) and more.
RGBLED - Control the RGB LED at the back of the device.
Icons - Define and show simple icons.
MyShapes - Define and show own defined shapes (B4X code).
7-Segment-Display - 7-Segment font.
HeaderFooter - Header and footer which could be used for pages.
StopWatch - Stopwatch with 7-segment display and touch buttons.
Linechart - Simple line chart.
Gauge - 4 gauges with min, max, actual value.
MultiPages - Define multiple pages and select via touch.
Helper - Helper methods (B4X code) to be used in own programs.

B4R Basic Example

B4X: Copy

#Region Project Attributes
    #AutoFlushLogs: True
    #CheckArrayBounds: True
    #StackBufferSize: 600
    'Set the display driver (mandatory)
    #DefineExtra: #define ESP32_2432S028
#End Region

Sub Process_Globals
    Private VERSION As String = "rLovyanGFXEx Basic v20250409"
    Public Serial1 As Serial
    Private lcd As LovyanGFXEx
End Sub

Private Sub AppStart
    Serial1.Initialize(115200)
    Log(CRLF, CRLF, "[AppStart]", VERSION)
    lcd.Initialize(Null)
    CallSubPlus("Demo", 500, 5)
End Sub

Private Sub Demo(tag As Byte)
    lcd.DisplayRotation = 1
    lcd.BackgroundColor = lcd.COLOR_WHITE
    lcd.DrawHeader(VERSION, lcd.FONT_FONT2, lcd.TEXT_ALIGN_CENTER, 1, lcd.COLOR_WHITE, lcd.COLOR_NAVY, lcd.COLOR_RED)
    lcd.DrawFooter("B4X=great... enjoy", lcd.FONT_FONT2, lcd.TEXT_ALIGN_CENTER, 1, lcd.COLOR_WHITE, lcd.COLOR_NAVY, lcd.COLOR_RED)
    lcd.FillCircle(30, 30, 15, lcd.COLOR_RED)
    lcd.FillRoundRect(10, 70, 50, 20, 5, lcd.COLOR_RED)
 
    ' Set cursor at x,y position
    Dim x,y As ULong
    x = 100
    y = 100
    lcd.SetCursor(x,y)

    ' Print text in red at cursor position
    lcd.Font = lcd.FONT_FONT0
    lcd.SetTextSize(3)
    lcd.SetTextColor(lcd.ColorRGB(255,0,0))
    lcd.Print("HELLO")

    ' Print text in white at new cursor position
    lcd.SetCursor(100,200)
    lcd.SetTextSize(3)
    lcd.SetTextColor(lcd.ColorRGB(255,255,255))
    lcd.Print("World")

    ' Draw blue pixel
    lcd.DrawPixel(50, lcd.Height / 2 , lcd.COLOR_BLUE)

    ' Draw lines
    lcd.DrawLine(60, 60, 100, 100, lcd.ColorRGB(255,0,0))
    'lcd.DrawLine(10, lcd.Height - 20, lcd.Width - 20, lcd.Height - 20, lcd.COLOR_BLUE)
    lcd.DrawGradientLine(10, lcd.Height - 20, lcd.Width - 20, lcd.Height - 20, lcd.COLOR_RED, lcd.color_BLACK)
    lcd.DrawWideLine(10, lcd.Height / 2, lcd.Width / 2, lcd.Height / 2, 5, lcd.COLOR_CYAN)

    ' 3-point black Bezier curve
    lcd.drawBezier3(10, 200, 100, 150, 150, 200, lcd.COLOR_BLACK)
 
    ' Draw circles
    lcd.DrawCircle(60, 60, 20, lcd.COLOR_BLUE)
    'lcd.FillCircle(60, 60, 20, lcd.ColorRGB(255,0,0))
    'Dim c As ULong = Bit.ParseInt("000000FF", 32)
    'lcd.FillCircle(60, 60, 20, c)
    'lcd.FillCircle(150, 150, 20, lcd.COLOR_RED)

    ' Little triangle
    lcd.fillTriangle(80, 80, 60, 80, 80, 60, lcd.COLOR_YELLOW)
 
    ' Draw TextBox
    lcd.DrawTextBox((lcd.Width / 2) - (100 / 2), 30, 100, 40, "INFO", lcd.COLOR_BLACK, 2, lcd.COLOR_WHITE, lcd.COLOR_RED, 4)
    lcd.DrawTextBoxMultiLIne(200, 80, 100, 130, "Line1", "Line2", "Line3", lcd.COLOR_BLACK, 0, lcd.COLOR_LIGHTGRAY, lcd.COLOR_RED, 4)
End Sub

To-Do

Sunton test GPIO to connect peripherals: GPIO 35 (P3 connector), GPIO 22 (P3 and CN1 connector), GPIO 27 (CN1 connector)

Credits

Developer(s) of the LovyanGFX library.
and of course Anywhere Software for providing the B4X suite of development tools plus the B4X community for sharing solutions&hints.

License
GNU General Public License v3.0.

Hints
Some hints gathered during library development using the Sunton ESP32 2.8" TFT Cheap Yellow Display.

Get Started
To get started with the LovyanGFX library, open the Arduino IDE and add the LovyanGFX library (manage libraries).
Create a new sketch, copy the TFT LCD Display Driver ILI9341 header file "ESP32_2432S028.h" to the sketch folder location, compile & upload.
The goal of using the Arduino IDE first prior B4R developments, is to test if the LovyanGFX library is working with the selected hardware.
Lookup and modify the TFT LCD Display Driver ILI9341 header file "ESP32_2432S028.h" as required.
If another device is used, checkout the LovyanGFX GitHub repository.

After successful use of the library in the Arduino IDE, start with B4R Inline C calling the library functions. If that is working, wrapping the library can begin...

Arduino CPP Sketch LovyanGFX_HelloWorld
Show the text Hello World.

B4X: Copy

// LovyanGFX_HelloWorld - Sunton ESP32 2.8" TFT Cheap Yellow Display
#define LGFX_USE_V1
#include <LovyanGFX.hpp>
#include "ESP32_2432S028.h"

LGFX lcd;
int32_t x;
int32_t y;

void hello_world()
{
  lcd.fillScreen(TFT_WHITE);

  x = lcd.width() / 2;
  y = lcd.height() / 4;

  // Show text using set cursor and println
  lcd.setCursor(x, y);
  lcd.setTextSize(2);
  lcd.setTextColor(TFT_BLACK);
  lcd.println("HELLO");

  // Show text using drawString
  y = lcd.height() / 2;
  lcd.setTextSize(3);
  lcd.setTextColor(TFT_RED);
  lcd.setTextDatum(MR_DATUM);
  lcd.drawString("WORLD", x, y);
}

void setup(void)
{
  Serial.begin(115200);
  lcd.init();
  delay(100);
  hello_world();
}

void loop(void)
{
  // No tasks
}

Arduino CPP Sketch LovyanGFX_Touch
Handle touch > show position.

Code: Copy

// LovyanGFX_Touch - Sunton ESP32 2.8" TFT Cheap Yellow Display
#define LGFX_USE_V1
#include <LovyanGFX.hpp>
#include "ESP32_2432S028.h"
#define MAX_X 319
#define MAX_Y 239

uint16_t touchX = 0, touchY = 0, touchZ = 0;

static LGFX lcd;

void setup(void) {
  Serial.begin(115200);
  lcd.init();
  lcd.setRotation(1);
  lcd.fillScreen(TFT_WHITE);
  delay(100);

  // Show text using drawString
  lcd.setTextSize(2);
  lcd.setTextColor(TFT_RED);
  lcd.setTextDatum(MC_DATUM);
  lcd.drawString("Touch Example", lcd.width() / 2, lcd.height() / 2);
}

void loop() {
  // Listen to touch
  touchZ = lcd.getTouch(&touchX, &touchY);

  // If panel touched, 1 is returned
  if (touchZ == 1) {

    // Check touch boundaries
    if (touchX < 1 || touchX > MAX_X * 2) touchX = 0;
    if (touchX > MAX_X && touchX < MAX_Y * 2) touchX = MAX_Y;
    if (touchY < 1 || touchY > MAX_Y * 2) touchY = 0;
    if (touchY > MAX_Y && touchY < MAX_Y * 2) touchY = MAX_Y;

    // Clear the screen
    lcd.clear(TFT_WHITE);

    // Show touch position @ screen top left
    lcd.setCursor(10, 10);
    lcd.setTextSize(1);
    lcd.setTextColor(TFT_BLACK);
    lcd.printf("touchX=%d, touchY=%d, touchZ=%d", touchX, touchY, touchZ);

    // Show red dot at touch position
    lcd.fillCircle( (int32_t) touchX, (int32_t) touchY, (int32_t) 10, TFT_RED);
  }

  delay(100);
}

After testing the library with the Ardiuno IDE, test the library with **B4R and Inline C**.
Next two programs to show Hello World and handle touch events.

B4R Inline C Hello World
Test using the LovyanGFX library direct in B4R code with Inline C.

B4X: Copy

Sub Process_Globals
    Private VERSION As String = "LovyanGFX InlineC v20250320"
    Public Serial1 As Serial
End Sub

Private Sub AppStart
    Serial1.Initialize(115200)
    Log(CRLF, CRLF, "[AppStart]", VERSION)

    'Init display without touch
    RunNative("initDisplay", Null)

    'Call method demo
    CallSubPlus("Demo", 500, 5)
End Sub

Private Sub Demo(tag As Byte)
    RunNative("setHelloWorld", Null)
End Sub

#If C

#define LGFX_USE_V1
#include <LovyanGFX.hpp>

// Set the path to the display driver header located in the same folder as the B4R program.
// The B4R compiled source is in folder Object/src/ and references in b4r_main.cpp
#include "..\..\ESP32_2432S028.h"

LGFX lcd;

int32_t x;
int32_t y;

void initDisplay(B4R::Object* o) {

  lcd.init();
  lcd.setRotation(1);
  lcd.fillScreen(TFT_WHITE);
}

void setHelloWorld(B4R::Object* o)
{
  lcd.fillScreen(TFT_WHITE);

  x = lcd.width() / 2;
  y = lcd.height() / 4;

  // Show text using set cursor and println
  lcd.setCursor(x, y);
  lcd.setTextSize(2);
  lcd.setTextColor(TFT_BLACK);
  lcd.println("HELLO");

  // Show text using drawString
  y = lcd.height() / 2;
  lcd.setTextSize(3);
  lcd.setTextColor(TFT_RED);
  lcd.setTextDatum(MR_DATUM);
  lcd.drawString("WORLD", x, y);
}
#End If

B4R Inline C Touch
Test using the LovyanGFX library direct in B4R code with Inline C.

B4X: Copy

Sub Process_Globals
    Private VERSION As String = "LovyanGFX InlineC Touch v20250320"
    'Communication
    Public Serial1 As Serial
    ' Define the user defined type
    Type TTouchPosition(x As Int, y As Int)
    Private TouchPos As TTouchPosition
End Sub

Private Sub AppStart
    Serial1.Initialize(115200)
    Log(CRLF, CRLF, "[AppStart]", VERSION)
    'Init display without touch
    RunNative("initDisplay", Null)
    'Start the looper to handle touch
    AddLooper("LooperTouch")
End Sub

Private Sub LooperTouch
    RunNative("getTouch", Null)
End Sub

Private Sub OnTouch(x As Int, y As Int)    'ignore
    Log("[OnTouch] x=",x,",y=",y)
    TouchPos.x = x
    TouchPos.y = y
    RunNative("setText", TouchPos)
End Sub

#If C

#define LGFX_USE_V1
#include <LovyanGFX.hpp>

// Set the path to the display driver header located in the same folder as the B4R program.
// The B4R compiled source is in folder Object/src/ and references in b4r_main.cpp
#include "..\..\ESP32_2432S028.h"

#define MAX_X 319
#define MAX_Y 239

uint16_t touchX = 0, touchY = 0, touchZ = 0;

static LGFX lcd;

void initDisplay(B4R::Object* o) {

  lcd.init();
  lcd.setRotation(1);
  lcd.fillScreen(TFT_WHITE);
}

void getTouch(B4R::Object* o) {
  // Listen to touch
  touchZ = lcd.getTouch(&touchX, &touchY);

  // If panel touched, 1 is returned
  if (touchZ == 1) {

    // Check touch boundaries
    if (touchX < 1 || touchX > MAX_X * 2) touchX = 0;
    if (touchX > MAX_X && touchX < MAX_Y * 2) touchX = MAX_Y;
    if (touchY < 1 || touchY > MAX_Y * 2) touchY = 0;
    if (touchY > MAX_Y && touchY < MAX_Y * 2) touchY = MAX_Y;

    // Clear the screen
    lcd.clear(TFT_WHITE);

    // Show touch position @ screen top left
    lcd.setCursor(10, 10);
    lcd.setTextSize(1);
    lcd.setTextColor(TFT_BLACK);
    lcd.printf("touchX=%d, touchY=%d, touchZ=%d", touchX, touchY, touchZ);

    // Show red dot at touch position
    lcd.fillCircle( (int32_t) touchX, (int32_t) touchY, (int32_t) 10, TFT_RED);

    // Call the B4R Sub (note the lowercase)
    b4r_main::_ontouch(touchX, touchY);
  }

  delay(100);
}

void setText(B4R::Object* o) {
    // Get the defined object
    _ttouchposition* touchpos = (_ttouchposition *)B4R::Object::toPointer(o);

    // Get data from the object pointer with structure x,y
    int x = touchpos->x;
    int y = touchpos->y;
    char posString[20];
    sprintf(posString, "%3d,%3d",x,y);
    lcd.setTextSize(2);
    lcd.setTextDatum(MC_DATUM);
    lcd.drawString(posString, x, y);
}
#End If

Last edited: Jun 8, 2025

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B4R Library rLovyanGFXEx ESP32

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