/*
**  Author: Aniket Biswas
**  Github: https://github.com/aniket-hpp
**  
**  Example for TFT_eSPI_Scroll library
**
**  Contribute to improve the library
*/

#include <Arduino.h>
#include <TFT_eSPI.h>
#include "TFT_eSPI_Scroll.h"
#include "4bit.h"

TFT_eSPI tft;
TFT_eSPI_Scroll scroll;
int count = 1;

void setup(){
    // Initializing tft_espi
    tft.init();    
    Serial.begin(9600);

    // Initializing the tft_espi_scroll int 1bit B/W
    if(scroll.init(&tft, 4) != NO_ERROR){
        Serial.println("Failed... Reseting...");        
        return;
    }

    String data;

    for(int i = 1; i <= 100; i++){
        data = String("Count: ") + String(i); 
        scroll.write(data);
     
        //must be called for longer loops
        //otherwise watchdog will reset the mcu
        yield(); 
    }

    delay(2000);

    // reseting
    scroll.reset();

    // for 4bit
    scroll.init(&tft, 4, 4);
    scroll.setColor(COLOR_BLUE_4B, COLOR_RED_4B);
}

void loop(){
    scroll.write("2 x " + String(count) + " = " + String(2*count++));
    delay(100);
}

TEST-TFT_eSPI.ino

diagram.json

TFT_eSPI@wokwi:e05dd5def8f952d3f56c5f0b6f6fcfffe80b6b01


libraries.txt


/*
**  Author: Aniket Biswas
**  Github: https://github.com/aniket-hpp
**  
**  Library to add Vertical text Scrolling functionality to TFT_eSPI library by bodmer.
**  TFT_eSPI: https://github.com/Bodmer/TFT_eSPI
**
**  Contribute to improve the library
*/

/*
**  SEE examples for usage
*/

#ifndef _TFT_ESPI_SCROLL_H_
#define _TFT_ESPI_SCROLL_H_

#include <Arduino.h>
#include <TFT_eSPI.h>

#include "./1bit.h"
#include "./4bit.h"

#define TFT_eSPI_Scroll_Version "1.0.3"

/*
**  Error Handeling
**  Returns NO_ERROR if everthing is ok
*/
enum TFT_eSPI_Scroll_Error{
    NO_ERROR,
    ERROR_NO_TFT,
    ERROR_SPRITE_MEMORY_ALLOCATION_FAILED
};


/*
** TFT_eSPI_Scroll
** Enables text scrolling
*/

class TFT_eSPI_Scroll{
public:

    // Constructor
    TFT_eSPI_Scroll();
    // Destructor
    ~TFT_eSPI_Scroll();

    /*
    ** @name init
    ** @brief Initializes the class with neccessary datas.
    ** @brief It is recommended to use default 1-bit color_depth [B/W] for flickerless screen refresh & low ram usage
    ** @param TFT_eSPI*
    ** @param text_font
    ** @param color_depth
    */
    TFT_eSPI_Scroll_Error init(TFT_eSPI *tft_espi, uint16_t text_font, uint8_t color_depth = 1);
    
    /*
    ** @name write
    ** @brief Writes a line to the screen while scrolling.
    ** @param text
    */
    TFT_eSPI_Scroll_Error write(String text);

    /*
    ** @name setColor
    ** @brief Sets an background and foreground color
    ** @brief It is recommended to use default 1-bit color settings [B/W] for flickerless screen refresh & low ram usage.
    ** @brief Color depth must be set accordingly.
    ** @param background_color
    ** @param foreground_color
    */
    void setColor(uint16_t background_color, uint16_t forground_color);

    /*
    ** @name reset
    ** @brief Resets configs, init must be called 
    */ 
    void reset();

private:
    // Scrolls the screen by shifting all lines by -1
    void shift(int text_width);

    int width, height; //screen size
    int font_height, cursor;

    //stroing the lines in display 
    std::vector<String> buffer;
    TFT_eSPI *tft; //tft_espi display driver
    TFT_eSprite *sprite; //sprite for flicker less update
    uint16_t bg_color;
};

#endif


TFT_eSPI_Scroll.h


/*
**  Author: Aniket Biswas
**  Github: https://github.com/aniket-hpp
**  
**  Library to add Vertical text Scrolling functionality to TFT_eSPI library by bodmer.
**  Header File: TFT_eSPI_Scroll.h
**  TFT_eSPI: https://github.com/Bodmer/TFT_eSPI
*/

#include <Arduino.h>
#include <TFT_eSPI.h>
#include "./TFT_eSPI_Scroll.h"

// Constructor
TFT_eSPI_Scroll::TFT_eSPI_Scroll(){
    this->cursor = 0;
}

// Destructor
TFT_eSPI_Scroll::~TFT_eSPI_Scroll(){
    buffer.clear();
    sprite->deleteSprite();
    delete sprite;
}

/*
** @name init
** @brief Initializes the class with neccessary datas.
** @param TFT_eSPI*
** @param text_font
** @param bg_color
** @param fg_color
*/
TFT_eSPI_Scroll_Error TFT_eSPI_Scroll::init(TFT_eSPI *tft_espi, uint16_t text_font, uint8_t color_depth){
    if(tft_espi == NULL) return ERROR_NO_TFT;

    tft = tft_espi;
    sprite = new TFT_eSprite(tft);
    sprite->setColorDepth(color_depth);
    this->width = tft->width();
    this->height = tft->height();
    
    if(!sprite->createSprite(width, height)){
        tft = NULL;
        return ERROR_SPRITE_MEMORY_ALLOCATION_FAILED;
    }

    sprite->setTextFont(text_font);
    this->font_height = sprite->fontHeight(text_font);
    sprite->fillScreen(bg_color = COLOR_BLACK_1B);
    sprite->setTextColor(COLOR_WHITE_1B);

    return NO_ERROR;
}

/*
** @name write
** @brief Writes a line to the screen while scrolling.
** @param text
*/
TFT_eSPI_Scroll_Error TFT_eSPI_Scroll::write(String text){
    // if init is not called then return
    if(!tft) return ERROR_NO_TFT;
    // computes the text-width and text-height
    int text_height = font_height, text_width = sprite->textWidth(text);
    if(text_width > width) text_height = ceil(text_width/(float)width) * font_height;
    
    // if the text cannot be fitted in the screen then we shift the texts in screen
    // to make room
    if(cursor + text_height >= height){shift(text_height);}
    
    // after shifting, previous string is filled with a rect
    // then text gets printed to the screen
    sprite->fillRect(0, cursor, width, text_height, bg_color);
    sprite->setCursor(0, cursor);
    sprite->print(text);
    sprite->pushSprite(0, 0);

    // stroing current string in buffer vector
    buffer.push_back(text);

    // preparing the cursor for the next line
    cursor += text_height;
    return NO_ERROR;
}

/*
** @name shift
** @brief Shift the whole screen by -1.
** @param text_height
*/
void TFT_eSPI_Scroll::shift(int text_height){
    int line_width, line_height;

    // making the room for the new string at the bottom
    // by removing texts from the top of the screen
    for(String &line : buffer){
        if(cursor + text_height < height) break;
        
        line_height = (ceil(sprite->textWidth(line)/(float)width) * font_height);
        buffer.erase(buffer.begin());
        
        cursor -= line_height;
    }


    int extra_cursor = 0;

    // reprinting the whole text buffer after covering the previous texts
    // with rect
    for(String &line : buffer){
        line_height = font_height;
        line_width = sprite->textWidth(line);
        if(line_width > width) line_height = (ceil(line_width/(float)width) * font_height);
        
        sprite->fillRect(0, extra_cursor, (line_width<width)?line_width:width, line_height, bg_color);            
        sprite->setCursor(0, extra_cursor);
        sprite->print(line);

        extra_cursor += line_height;
    }
}

/*
** @name setColor
** @brief Sets an background and foreground color.
** @brief Color depth must be set accordingly.
** @param background_color
** @param foreground_color
*/
void TFT_eSPI_Scroll::setColor(uint16_t background_color, uint16_t forground_color){
    sprite->fillScreen(bg_color = background_color);
    sprite->setTextColor(forground_color);
}



/*
** @name reset 
** @brief Resets scroll 
*/
void TFT_eSPI_Scroll::reset(){
    buffer.clear();
    sprite->deleteSprite();
    delete sprite;
    cursor = 0;
}


TFT_eSPI_Scroll.cpp

/*
**  Author: Aniket Biswas
**  Github: https://github.com/aniket-hpp
**  
**  1Bit color 
**
**  Contribute to improve the library
*/

#ifndef _1BIT_COLOR_H_
#define _1BIT_COLOR_H_

enum _1BIT_COLOR_{
    COLOR_BLACK_1B,
    COLOR_WHITE_1B
};

#endif

1bit.h

/*
**  Author: Aniket Biswas
**  Github: https://github.com/aniket-hpp
**  
**  4Bit color 
**
**  Contribute to improve the library
*/

#ifndef _4BIT_COLOR_H_
#define _4BIT_COLOR_H_

enum _4BIT_COLOR_{
    COLOR_BLACK_4B,
    COLOR_BROWN_4B,
    COLOR_RED_4B,  
    COLOR_ORANGE_4B,
    COLOR_YELLOW_4B,
    COLOR_GREEN_4B, 
    COLOR_BLUE_4B,  
    COLOR_PURPLE_4B,
    COLOR_DARKGREY_4B,
    COLOR_WHITE_4B,   
    COLOR_CYAN_4B,    
    COLOR_MAGENTA_4B, 
    COLOR_MAROON_4B,  
    COLOR_DARKGREEN_4B,
    COLOR_NAVY_4B,     
    COLOR_PINK_4B      
};

#endif