Subclass that you can use jointly with https://github.com/yoprogramo/QRcodeDisplay to generate QRcodes in TFT displays like ST7789
To use it:
Add as dependencies:
- yoprogramo/QRcodeDisplay
- yoprogramo/QRcode_ST7789
- adafruit/Adafruit GFX Library
- adafruit/Adafruit ST7735 and ST7789 Library
Open Library Manager (menu Sketch > Include Library > Manage Libraries…) then install the following libraries:
- QRcodeDisplay
- QRcode_ST7789
- Adafruit GFX Library
- adafruit/Adafruit ST7735 and ST7789 Library
Creating a QRcode is just as simple as (note we are using a Lilygo board that does not expose the SPI interface and we have to use other SPI):
#define TFT_RST       23    
#define TFT_CS        5     
#define TFT_DC        16  
#define TFT_BACKLIGHT 4
#define TFT_MOSI      19
#define TFT_SCLK      18  
#include <Adafruit_GFX.h>      
#include <Adafruit_ST7789.h>   
#include <SPI.h>
#include <qrcode_st7789.h>
Adafruit_ST7789 display = Adafruit_ST7789(&SPI, TFT_CS, TFT_DC, TFT_RST);
QRcode_ST7789 qrcode (&display);
void setup() {
   Serial.begin(115200);
   Serial.println("");
   Serial.println("Starting...");
   // enable debug qrcode
   // qrcode.debug();
   SPI.begin(TFT_SCLK,TFT_RST,TFT_MOSI,TFT_CS);
   display.init(135,240);
   pinMode(TFT_BACKLIGHT, OUTPUT);
   digitalWrite(TFT_BACKLIGHT, HIGH);
   // Initialize QRcode display using library
   qrcode.init();
   // create qrcode
   qrcode.create("Hello world.");
}
void loop() { }
For other displays, please refer the main repository: https://github.com/yoprogramo/QRcodeDisplay