Two dimensional code generation based on MCU and two dimensional code display on ink screen

        Ink screen compared with others LCD The screen has a significant advantage in low power consumption , It is especially suitable for button battery or even battery free nfc Application of price tag . Price tags often display QR codes , So I found a suitable one on the Internet mcu QR code generation library for use on .

        GitHub - ricmoo/QRCode: QR code generation library in C, optimized for low-power devices, such as Arduino.

        This qrcode It's very suitable for mcu On , Just one .c and .h file .

        Usage flow ：

    // Create the QR code  Generate the corresponding QR code according to the required string 
    QRCode qrcode;
    uint8_t qrcodeData[qrcode_getBufferSize(3)];
    qrcode_initText(&qrcode, qrcodeData, 3, 0, "https://blog.csdn.net/hydfxy2018");
    printf( "qrcode.size:%d\r\n", qrcode.size);

qrcode_getBufferSize(3) Parameters here 3 On behalf of the use of qr version3, The resolution of QR code generated by different versions is different .

Version	Size	Error Correction	Mode
			Numeric	Alphanumeric	Byte
1	21 x 21	LOW	41	25	17
		MEDIUM	34	20	14
		QUARTILE	27	16	11
		HIGH	17	10	7
2	25 x 25	LOW	77	47	32
		MEDIUM	63	38	26
		QUARTILE	48	29	20
		HIGH	34	20	14
3	29 x 29	LOW	127	77	53
		MEDIUM	101	61	42
		QUARTILE	77	47	32
		HIGH	58	35	24

This part is in qrcode There are instructions in the warehouse , According to the above, you can choose the appropriate version and the corresponding ecc Set up .

The generated QR code is displayed on the ink screen

for (uint8_t y = 0; y < qrcode.size; y++) {
		for (uint8_t x = 0; x < qrcode.size; x++) {
			if (qrcode_getModule(&qrcode, x, y)) {
				Paint_DrawFillRect(0 + x * 3,
						150 +  y * 3, 3, 3);
			} 
		}
	}

The principle is based on two-dimensional code code Dot display on the screen , Here, you can also adjust the size of the actual QR code through the size of the point , Press each point as above 3 Pixel setting .

The display effect is as follows ：

 

The complete code reference is as follows ：

GitHub - iot-lorawan/MCU_QRCode_LCD: Ink-Display with QRCode in MCU