multiple_lcd_test.cpp

// https://ee-programming-notepad.blogspot.com/2016/10/c-array-of-pointers-to-objects.html
#include "mbed.h"
#include "ILI9340_Driver.h"

#define LCD_MOSI D11
#define LCD_MISO D12
#define LCD_SCK  D13
#define LCD_DC   D7

#define LCD1_RST  D3
#define LCD1_CS   D5
#define LCD2_RST  A1
#define LCD2_CS   A0

#define LCD_NO_SCREENS 2

ILI9340_Display * tft_lcds[LCD_NO_SCREENS];

int main() {
    char i = 0;
    PinName cs_pin, rst_pin;
    ILI9340_Display * tft_lcd; // array of pointers to objects
    while (i < LCD_NO_SCREENS) // iterate the screens
    {
        switch (i)
        {
            case 0: // first screen
                cs_pin = LCD1_CS;
                rst_pin = LCD1_RST;
                break;
            case 1: // second screen
                cs_pin = LCD2_CS;
                rst_pin = LCD2_RST;
                break;
        }

        // instantiate the LCD class
        tft_lcd = new ILI9340_Display(LCD_MOSI, LCD_MISO, LCD_SCK, cs_pin, rst_pin, LCD_DC); // MOSI, MISO, SCK, CS, RST, D/C
        tft_lcd->DispInit();
        tft_lcd->SetRotation(0);
        tft_lcd->FillScreen(ILI9340_BLUE);
        // push the new instance to the array of pointers
        tft_lcds[i] = tft_lcd;
        i++;
    }

    // ... code ...
    wait(2);

    // later on, display some text on LCD
    i = 0;
    while (i < LCD_NO_SCREENS)
    {
        tft_lcds[i]->FillScreen(ILI9340_RED);

        char buff[20];
        sprintf(buff, "Loading %d...", i);
        tft_lcds[i]->DrawString(buff, 0, 0, 2, ILI9340_WHITE); // draw a text with 8px font
        i++;
    }
}