QR to bitmap to print via Thermal Printer

[janna574]

how can i get a bitmap from qrcode to print via ThermalPrinter !

printer.printBitmap(50,50,qrcode data,false);

[1000283]

You need to use the GS ( k family of commands, if the printer supports it.
Or convert the QR code to a bitmap and try GS v 0 or ESC *.

[aaron-neal]

Hope this helps....
Example below generates a WiFi QR code.
It is a version 3 code, then printed at 5 times the size.

if (tpScan("", 1)) {
        Serial.println((char *)"Found a printer!, connecting...");
        if (tpConnect()){
            uint8_t qrVersion = 3;
            static uint8_t ucBuf[48 * 160]; //tp printer buffer 48 * ver lines
            tpSetBackBuffer(ucBuf, 384, 160);
            
            tpFill(0);
            char buf[50];
            sprintf(buf, "WIFI:S:%s;T:WPA;P:%s;;", config.networkConfig.apSSID, config.networkConfig.apPassword);
            Serial.println(buf);
            uint8_t qrcodeData[qrcode_getBufferSize(qrVersion)];
            qrcode_initText(&qrcode, qrcodeData, qrVersion, 0, buf); //ver 3 = 29*29 //ver 40 177*177

            uint8_t startX = 117;
            uint8_t startY = 10;

            for (uint8_t y = 0; y < qrcode.size; y++) {
                for (uint8_t x = 0; x < qrcode.size; x++) {
                    if (qrcode_getModule(&qrcode, x, y) == 1){    
                        //below, print QR 5 times as big                
                        tpSetPixel(startX + 5 * x,     startY + 5 * y, 1);
                        tpSetPixel(startX + 5 * x + 1, startY + 5 * y, 1);
                        tpSetPixel(startX + 5 * x + 2, startY + 5 * y, 1);
                        tpSetPixel(startX + 5 * x + 2, startY + 5 * y, 1);
                        tpSetPixel(startX + 5 * x + 2, startY + 5 * y, 1);
                            
                        tpSetPixel(startX + 5 * x,     startY + 5 * y + 1, 1);
                        tpSetPixel(startX + 5 * x + 1, startY + 5 * y + 1, 1);
                        tpSetPixel(startX + 5 * x + 2, startY + 5 * y + 1, 1);
                        tpSetPixel(startX + 5 * x + 3, startY + 5 * y + 1, 1);
                        tpSetPixel(startX + 5 * x + 4, startY + 5 * y + 1, 1);

                        tpSetPixel(startX + 5 * x,     startY + 5 * y + 2, 1);
                        tpSetPixel(startX + 5 * x + 1, startY + 5 * y + 2, 1);
                        tpSetPixel(startX + 5 * x + 2, startY + 5 * y + 2, 1);   
                        tpSetPixel(startX + 5 * x + 3, startY + 5 * y + 2, 1);   
                        tpSetPixel(startX + 5 * x + 4, startY + 5 * y + 2, 1);   

                        tpSetPixel(startX + 5 * x,     startY + 5 * y + 3, 1);
                        tpSetPixel(startX + 5 * x + 1, startY + 5 * y + 3, 1);
                        tpSetPixel(startX + 5 * x + 2, startY + 5 * y + 3, 1);   
                        tpSetPixel(startX + 5 * x + 3, startY + 5 * y + 3, 1);   
                        tpSetPixel(startX + 5 * x + 4, startY + 5 * y + 3, 1);  

                        tpSetPixel(startX + 5 * x,     startY + 5 * y + 4, 1);
                        tpSetPixel(startX + 5 * x + 1, startY + 5 * y + 4, 1);
                        tpSetPixel(startX + 5 * x + 2, startY + 5 * y + 4, 1);   
                        tpSetPixel(startX + 5 * x + 3, startY + 5 * y + 4, 1);   
                        tpSetPixel(startX + 5 * x + 4, startY + 5 * y + 4, 1);  
                    }
                }
            }
            tpPrintBuffer();
            tpDisconnect();
        }
    } else {
        Serial.println((char *)"Didn't find a printer :( ");
    }

[lailuboy]

I implemented saving a QR code as a BMP file using C language