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QR code generation library in C, optimized for low-power devices, such as Arduino.

License: Other

C 37.71% C++ 57.10% Shell 0.24% Python 4.95%

arduino arduino-library qrcode qr-code qr-generator

qrcode's Introduction

QRCode

A simple library for generating QR codes in C, optimized for processing and memory constrained systems.

Features:

Stack-based (no heap necessary; but you can use heap if you want)
Low-memory foot print (relatively)
Compile-time stripping of unecessary logic and constants
MIT License; do with this as you please

Installing

To install this library, download and save it to your Arduino libraries directory.

Rename the directory to QRCode (if downloaded from GitHub, the filename may be qrcode-master; library names may not contain the hyphen, so it must be renamed)

API

Generate a QR Code

// The structure to manage the QR code
QRCode qrcode;

// Allocate a chunk of memory to store the QR code
uint8_t qrcodeBytes[qrcode_getBufferSize()];

qrcode_initText(&qrcode, qrcodeBytes, 3, ECC_LOW, "HELLO WORLD");

Draw a QR Code

How a QR code is used will vary greatly from project to project. For example:

Display on an OLED screen (128x64 nicely supports 2 side-by-side version 3 QR codes)
Print as a bitmap on a thermal printer
Store as a BMP (or with a some extra work, possibly a PNG) on an SD card

The following example prints a QR code to the Serial Monitor (it likely will not be scannable, but is just for demonstration purposes).

for (uint8 y = 0; y < qrcode.size; y++) {
    for (uint8 x = 0; x < qrcode.size; x++) {
        if (qrcode_getModule(&qrcode, x, y) {
            Serial.print("**");
        } else {
            Serial.print("  ");
        }
    }
    Serial.print("\n");
}

What is Version, Error Correction and Mode?

A QR code is composed of many little squares, called modules, which represent encoded data, with additional error correction (allowing partially damaged QR codes to still be read).

The version of a QR code is a number between 1 and 40 (inclusive), which indicates the size of the QR code. The width and height of a QR code are always equal (it is square) and are equal to 4 * version + 17.

The level of error correction is a number between 0 and 3 (inclusive), or can be one of the symbolic names ECC_LOW, ECC_MEDIUM, ECC_QUARTILE and ECC_HIGH. Higher levels of error correction sacrifice data capacity, but allow a larger portion of the QR code to be damaged or unreadable.

The mode of a QR code is determined by the data being encoded. Each mode is encoded internally using a compact representation, so lower modes can contain more data.

NUMERIC: numbers (0-9)
ALPHANUMERIC: uppercase letters (A-Z), numbers (0-9), the space ( ), dollar sign ($), percent sign (%), asterisk (*), plus (+), minus (-), decimal point (.), slash (/) and colon (:).
BYTE: any character

Data Capacities

Version	Size	Error Correction	Mode
Version	Size	Error Correction	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
4	33 x 33	LOW	187	114	78
		MEDIUM	149	90	62
		QUARTILE	111	67	46
		HIGH	82	50	34
5	37 x 37	LOW	255	154	106
		MEDIUM	202	122	84
		QUARTILE	144	87	60
		HIGH	106	64	44
6	41 x 41	LOW	322	195	134
		MEDIUM	255	154	106
		QUARTILE	178	108	74
		HIGH	139	84	58
7	45 x 45	LOW	370	224	154
		MEDIUM	293	178	122
		QUARTILE	207	125	86
		HIGH	154	93	64
8	49 x 49	LOW	461	279	192
		MEDIUM	365	221	152
		QUARTILE	259	157	108
		HIGH	202	122	84
9	53 x 53	LOW	552	335	230
		MEDIUM	432	262	180
		QUARTILE	312	189	130
		HIGH	235	143	98
10	57 x 57	LOW	652	395	271
		MEDIUM	513	311	213
		QUARTILE	364	221	151
		HIGH	288	174	119
11	61 x 61	LOW	772	468	321
		MEDIUM	604	366	251
		QUARTILE	427	259	177
		HIGH	331	200	137
12	65 x 65	LOW	883	535	367
		MEDIUM	691	419	287
		QUARTILE	489	296	203
		HIGH	374	227	155
13	69 x 69	LOW	1022	619	425
		MEDIUM	796	483	331
		QUARTILE	580	352	241
		HIGH	427	259	177
14	73 x 73	LOW	1101	667	458
		MEDIUM	871	528	362
		QUARTILE	621	376	258
		HIGH	468	283	194
15	77 x 77	LOW	1250	758	520
		MEDIUM	991	600	412
		QUARTILE	703	426	292
		HIGH	530	321	220
16	81 x 81	LOW	1408	854	586
		MEDIUM	1082	656	450
		QUARTILE	775	470	322
		HIGH	602	365	250
17	85 x 85	LOW	1548	938	644
		MEDIUM	1212	734	504
		QUARTILE	876	531	364
		HIGH	674	408	280
18	89 x 89	LOW	1725	1046	718
		MEDIUM	1346	816	560
		QUARTILE	948	574	394
		HIGH	746	452	310
19	93 x 93	LOW	1903	1153	792
		MEDIUM	1500	909	624
		QUARTILE	1063	644	442
		HIGH	813	493	338
20	97 x 97	LOW	2061	1249	858
		MEDIUM	1600	970	666
		QUARTILE	1159	702	482
		HIGH	919	557	382
21	101 x 101	LOW	2232	1352	929
		MEDIUM	1708	1035	711
		QUARTILE	1224	742	509
		HIGH	969	587	403
22	105 x 105	LOW	2409	1460	1003
		MEDIUM	1872	1134	779
		QUARTILE	1358	823	565
		HIGH	1056	640	439
23	109 x 109	LOW	2620	1588	1091
		MEDIUM	2059	1248	857
		QUARTILE	1468	890	611
		HIGH	1108	672	461
24	113 x 113	LOW	2812	1704	1171
		MEDIUM	2188	1326	911
		QUARTILE	1588	963	661
		HIGH	1228	744	511
25	117 x 117	LOW	3057	1853	1273
		MEDIUM	2395	1451	997
		QUARTILE	1718	1041	715
		HIGH	1286	779	535
26	121 x 121	LOW	3283	1990	1367
		MEDIUM	2544	1542	1059
		QUARTILE	1804	1094	751
		HIGH	1425	864	593
27	125 x 125	LOW	3517	2132	1465
		MEDIUM	2701	1637	1125
		QUARTILE	1933	1172	805
		HIGH	1501	910	625
28	129 x 129	LOW	3669	2223	1528
		MEDIUM	2857	1732	1190
		QUARTILE	2085	1263	868
		HIGH	1581	958	658
29	133 x 133	LOW	3909	2369	1628
		MEDIUM	3035	1839	1264
		QUARTILE	2181	1322	908
		HIGH	1677	1016	698
30	137 x 137	LOW	4158	2520	1732
		MEDIUM	3289	1994	1370
		QUARTILE	2358	1429	982
		HIGH	1782	1080	742
31	141 x 141	LOW	4417	2677	1840
		MEDIUM	3486	2113	1452
		QUARTILE	2473	1499	1030
		HIGH	1897	1150	790
32	145 x 145	LOW	4686	2840	1952
		MEDIUM	3693	2238	1538
		QUARTILE	2670	1618	1112
		HIGH	2022	1226	842
33	149 x 149	LOW	4965	3009	2068
		MEDIUM	3909	2369	1628
		QUARTILE	2805	1700	1168
		HIGH	2157	1307	898
34	153 x 153	LOW	5253	3183	2188
		MEDIUM	4134	2506	1722
		QUARTILE	2949	1787	1228
		HIGH	2301	1394	958
35	157 x 157	LOW	5529	3351	2303
		MEDIUM	4343	2632	1809
		QUARTILE	3081	1867	1283
		HIGH	2361	1431	983
36	161 x 161	LOW	5836	3537	2431
		MEDIUM	4588	2780	1911
		QUARTILE	3244	1966	1351
		HIGH	2524	1530	1051
37	165 x 165	LOW	6153	3729	2563
		MEDIUM	4775	2894	1989
		QUARTILE	3417	2071	1423
		HIGH	2625	1591	1093
38	169 x 169	LOW	6479	3927	2699
		MEDIUM	5039	3054	2099
		QUARTILE	3599	2181	1499
		HIGH	2735	1658	1139
39	173 x 173	LOW	6743	4087	2809
		MEDIUM	5313	3220	2213
		QUARTILE	3791	2298	1579
		HIGH	2927	1774	1219
40	177 x 177	LOW	7089	4296	2953
		MEDIUM	5596	3391	2331
		QUARTILE	3993	2420	1663
		HIGH	3057	1852	1273

Special Thanks

A HUGE thank you to Project Nayuki for the QR code C++ library which was critical in development of this library.

License

MIT License.

qrcode's People

Contributors

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Watchers

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qrcode's Issues

How to Store as a BMP?

I have some code!try save to a BMP!
but can't scan!
can you help me?




typedef struct tagBITMAPINFOHEADER {
	unsigned int  biSize;
	int   biWidth;
	int   biHeight;
	unsigned short   biPlanes;
	unsigned short   biBitCount;
	unsigned int  biCompression;
	unsigned int  biSizeImage;
	int   biXPelsPerMeter;
	int   biYPelsPerMeter;
	unsigned int  biClrUsed;
	unsigned int  biClrImportant;
} BITMAPINFOHEADER, *PBITMAPINFOHEADER;

typedef struct tagBITMAPFILEHEADER {
	unsigned short    bfType;
	unsigned int   bfSize;
	unsigned short    bfReserved1;
	unsigned short    bfReserved2;
	unsigned int   bfOffBits;
} BITMAPFILEHEADER, *PBITMAPFILEHEADER;

typedef struct tagRGBQUAD {
	unsigned char rgbBlue;
	unsigned char rgbGreen;
	unsigned char rgbRed;
	unsigned char rgbReserved;
}RGBQUAD;

typedef struct tagBITMAPINFO {
	BITMAPINFOHEADER    bmiHeader;
	RGBQUAD             bmiColors[1];
} BITMAPINFO, *PBITMAPINFO;
PBITMAPINFO BuildBitmapInfo(int biBitCount, int width, int height)
{
	PBITMAPINFO pInfo = 0;
	if (biBitCount == 1)
	{
		pInfo =	(PBITMAPINFO)malloc(sizeof(BITMAPINFOHEADER) + sizeof(RGBQUAD) * 2);
		int i = 0;
		for ( ; i < 2 ; i ++)
		{
			pInfo->bmiColors[i].rgbBlue = (unsigned char)(i*255);
			pInfo->bmiColors[i].rgbRed  = (unsigned char)(i*255);
			pInfo->bmiColors[i].rgbGreen = (unsigned char)(i*255);
			pInfo->bmiColors[i].rgbReserved = 0;
		}
	}
	else
		if (biBitCount == 8)
		{
			pInfo = (PBITMAPINFO)malloc(sizeof(BITMAPINFOHEADER) + sizeof(RGBQUAD) * 256);
			int i = 0;
			for (; i < 256 ; i ++)
			{
				pInfo->bmiColors[i].rgbBlue = (unsigned char)i;
				pInfo->bmiColors[i].rgbRed =  (unsigned char)i;
				pInfo->bmiColors[i].rgbGreen = (unsigned char)i;
				pInfo->bmiColors[i].rgbReserved = 0;
			}
		}
		else if (biBitCount == 24)
		{
			pInfo = (PBITMAPINFO)malloc(sizeof(BITMAPINFOHEADER));
		}
		else
			return NULL;

		pInfo->bmiHeader.biSizeImage = (width*biBitCount+31)/32*4*height;
		pInfo->bmiHeader.biBitCount = biBitCount;
		pInfo->bmiHeader.biClrImportant = 0;
		pInfo->bmiHeader.biClrUsed = 0;
		pInfo->bmiHeader.biCompression = 0;
		pInfo->bmiHeader.biHeight = height;
		pInfo->bmiHeader.biWidth = width;
		pInfo->bmiHeader.biPlanes = 1;
		pInfo->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
		pInfo->bmiHeader.biXPelsPerMeter = 0;
		pInfo->bmiHeader.biYPelsPerMeter = 0;

		return pInfo;
}

PBITMAPFILEHEADER  BuildBitmapFileHeader(unsigned int bfSize,unsigned int bfOffBits)
{
	PBITMAPFILEHEADER pHeader = (PBITMAPFILEHEADER)malloc(sizeof(BITMAPFILEHEADER));
	pHeader->bfOffBits = bfOffBits;
	pHeader->bfReserved1 = 0;
	pHeader->bfReserved2 = 0;
	pHeader->bfSize = bfSize;
	pHeader->bfType = 'M'*0X100+'B';
	return pHeader;
}

int SaveDIB(PBITMAPINFO pInfo,unsigned char * pData,char * FileName)
{
	FILE *file = fopen(FileName,"wb");
	if(file == 0)
		return 0;

	PBITMAPFILEHEADER	pFileHeader;

	unsigned int	FileLen =0,bfOffBits =0;
	if( pInfo->bmiHeader.biBitCount==1 )
	{
		FileLen=(pInfo->bmiHeader.biWidth+31)/32*4 * pInfo->bmiHeader.biHeight;
		bfOffBits=0x3E;
	}
	else if( pInfo->bmiHeader.biBitCount==8 )
	{
		FileLen=(pInfo->bmiHeader.biWidth+3) /4 *4 * pInfo->bmiHeader.biHeight;
		bfOffBits=0x436;
	}
	else if( pInfo->bmiHeader.biBitCount==24 )
	{
		FileLen=(pInfo->bmiHeader.biWidth*3+3)/4*4 * pInfo->bmiHeader.biHeight;
		bfOffBits=sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);//0x36;
	}
	printf("FileLen = %d  bfOffBits = %d",FileLen,bfOffBits);
	pFileHeader=BuildBitmapFileHeader(FileLen,bfOffBits);

	fwrite(&(pFileHeader->bfType),1,2,file);
	fwrite(&(pFileHeader->bfSize),1,4,file);
	fwrite(&(pFileHeader->bfReserved1),1,2,file);
	fwrite(&(pFileHeader->bfReserved2),1,2,file);
	fwrite(&(pFileHeader->bfOffBits ),1,4,file);
	//fwrite(pFileHeader,1,14,file);


	if( pInfo->bmiHeader.biBitCount==1 )
	{
		fwrite(pInfo,1,0x30,file);

	}

	if( pInfo->bmiHeader.biBitCount==8 )
	{
		fwrite(pInfo,1,0x428,file);

	}
	if( pInfo->bmiHeader.biBitCount==24 )
	{
		fwrite(pInfo,1,sizeof(BITMAPINFOHEADER),file);

	}
	fwrite(pData,1,pInfo->bmiHeader.biSizeImage,file);//dW*h

	fclose(file);

	if( pFileHeader )
		free(pFileHeader);

	pFileHeader = 0;
	return 1;
}

no border

no white border for rows, and lot's scanner can not find the generated qrcode.

Hard Fault for versions bigger than 4

Hi
I face hard fault error for versions bigger than 4.
I debugged the code step by step and I see that Micro goes to hard fault in this lines

uint8_t result[data->capacityBytes];
memset(result, 0, sizeof(result));

I checked result address and it is 0x00000002 which is not a valid RAM address

QR-code constrained to size 26 or less on ESP32.

Could some way of using PSRAM on the ESP32's be implemented?

Memory's filled on any QR Code that's larger than a 26.

Unable to print version 8 or higher on a display!

I'm using a NodeMCU (ESP12-E) with an I2C display 128x128px.
I'm able to print QR codes with versions up to 7 without any issue, but when I choose version 8 or higher nothing happens, the display stays black and ESP8266 blinks the LED constantly (even though I haven't declared it as output or done anything with it!)

Doesn't work with 300 character

can you help me the qr code can't scan with 300 character

#pragma mark generates compiler warnings

Please remove all #pragma marks from the source code.
Some compilers complain them with warnings.

Interleave the data in-place.

Just an idea for optimizing codeword memory allocation, but run the interleave in-place, so we don't need to allocate a new block of memory.

Not working with bigger string

Hello

I am using ESP8266 and E paper display
Problem is when I want to generate qr code from bigger string, here is my function that generate qr code:

void qrCard(const char *code)
{
  display.fillRect(0, 0, GxEPD_WIDTH, GxEPD_HEIGHT, GxEPD_WHITE);
  display.update();

  byte box_x = 33;
  byte box_y = 33;
  byte box_s = 4.5;
  byte init_x = box_x;

  display.updateWindow(0, 0, GxEPD_WIDTH, GxEPD_HEIGHT, false);

  // Create the QR code
  QRCode qrcode;
  uint8_t qrcodeData[qrcode_getBufferSize(4)];
  qrcode_initText(&qrcode, qrcodeData, 4, 0, code);

  for (uint8_t y = 0; y < qrcode.size; y++)
  {
    // Each horizontal module
    for (uint8_t x = 0; x < qrcode.size; x++)
    {

      // Print each module (UTF-8 \u2588 is a solid block)
      //Serial.print(qrcode_getModule(&qrcode, x, y) ? "\u2588\u2588": "  ");
      if (qrcode_getModule(&qrcode, x, y))
      {
        //Serial.println(py+ps);
        display.fillRect(box_x, box_y, box_s, box_s, GxEPD_BLACK);
      }
      else
      {
        //Serial.println(py+ps);
        display.fillRect(box_x, box_y, box_s, box_s, GxEPD_WHITE);
      }
      box_x = box_x + box_s;
    }
    display.updateWindow(0, box_y, 200, box_s, true);
    box_y = box_y + box_s;
    box_x = init_x;
  }
}

This is string which I try to use to generate qr code:

eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJjb2RlIjoiYjdlODg2NzAtNjJiNi0xMWU5LThlODEtYzk4YzQxODQwMzg4IiwiaWF0IjoxNTYzODAwMDQ0fQ.06H2CZHUoDdezXBFPk4kocK8Qqjgy3zmAR-OgMk4AH0

In console I get this error:

HTTPS Connecting
ets Jan 8 2013,rst cause:4, boot mode:(3,6)

wdt reset
load 0x4010f000, len 1384, room 16
tail 8
chksum 0x2d
csum 0x2d
v8b899c12
~ld
D�Done

Found out that this function creating error:
qrcode_initText

When I use smaller string it works. Any solution for this? Also is it possible to update qr code at once not part by part?

#EDIT: Did little debuging, first time error occure here:

bb_initGrid(&modulesGrid, modules, size); in this function qrcode_initBytes

Order of entries NUM_ERROR_CORRECTION_BLOCKS

Is the order of the elements in NUM_ERROR_CORRECTION_BLOCKS correct?
Currently it is written in the comment that it is Medium, Low, High, Quartile.

However they are accessed using the ecc value as index. In the header, the ECC values are defined as

#define ECC_LOW 0
#define ECC_MEDIUM 1
#define ECC_QUARTILE 2
#define ECC_HIGH 3

The same seem to be the case for NUM_ERROR_CORRECTION_CODEWORDS?

Precomputing the QR codes

Hi!

First of all thanks for this amazing library. It helped a lot to display QR codes on an OLED using Arduino.

I have a question that might be too simple. I want to precompute the QR codes in order to save time.
Is it possible to precompute and store them inside an array-like structure and draw them immediately.

The code works fine when I compute the QR code, i.e. call the qrcode_initText, and draw the image inside the same function call. But I failed to draw the QR codes properly with precomputing.
For precomputing, I tried computing them inside the setup() function and then print them after a button press inside the loop().

Below are the code snippets.

setup():

...
QRCode qrcode;



void setup() {
  Serial.begin(BAUD_RATE);

  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3D for 128x64
    Serial.println(F("SSD1306 allocation failed"));
    for (;;); // Don't proceed, loop forever
  }
  display.display();
  delay(2000);
  display.clearDisplay();
  display.setTextSize(3);             // Normal 1:1 pixel scale
  display.setTextColor(WHITE);        // Draw white text
  display.display();
  
  uint8_t qrcodeBytes[qrcode_getBufferSize(QR_VERSION)];
  qrcode_initText(&qrcode, qrcodeBytes, QR_VERSION, 0, "hello");

}

loop():

void loop() {

  if (Serial.available() > 0) {

    const uint8_t y0 = 10;
    const uint8_t x0 = 10;
    char data = Serial.read();
    if (data == 'Q') {
      display.clearDisplay();
      for (uint8_t y = 0; y < qrcode.size; y++)
      {
        for (uint8_t x = 0; x < qrcode.size; x++)
        {
          uint8_t pixel = 0;
          if (qrcode_getModule(&qrcode, x, y) )
          {
            /*Put black pixel*/
            pixel = 1;
          }
          else
          {
            /*White pixel*/
            pixel = 0;
          }

          display.drawPixel(x0 + 2 * x, y0 + y, pixel);
          display.drawPixel(x0 + 2 * x + 1, y0 + y, pixel);
        }
      }
      for (uint8_t y = 0; y < qrcode.size; y++) {
        for (uint8_t x = 0; x < qrcode.size; x++) {
          if (qrcode_getModule(&qrcode, x, y)) {
            Serial.print("**");
          } else {
            Serial.print("  ");
          }
        }
        Serial.print("\n");
      }

      // Bottom quiet zone
      Serial.print("\n\n\n\n");
    }
  }
  display.display();
  delay(2000);

  display.display();
  delay(1000);
}

However, I get a broken QR (image below) when I do this. I suspect the values inside the qrCodeBytes get changed between setup and loop.

Is it possible to add "carriage return" to Numeric mode?

Hi,
Is it possible to add "carriage return" to Numeric mode?
It seems it is not exist in ALPHANUMERIC too. So we should use Byte mode to have \r char.

memory out of range question

Hi friend, in line:

https://github.com/ricmoo/QRCode/blob/master/src/qrcode.c#L709

after this code, some code access the variable but out of range: [0, data->capacityBytes) .if i fix the error, the code likes uint8_t *result = new uint8_t [data->capacityBytes * 100];

after fix, i have generate image, but it can't scan from any qrcode app.such as:

ide: visual studio 2017

error: 'QRCode' was not declared in this scope

wondering what I am doing wrong, I am attempting to compile the example in my Arduino UI

https://github.com/ricmoo/QRCode/blob/master/examples/QRCode/QRCode.ino

I have installed the library using the Library Manager...

also check that it is installed...

libraries$ ls -al
total 28
drwxrwxr-x 7 clay clay 4096 Nov 20 22:32 .
drwxrwxr-x 4 clay clay 4096 Nov 20 22:26 ..
drwxrwxr-x 4 clay clay 4096 Nov 20 19:10 Base64
drwxrwxr-x 4 clay clay 4096 Nov 20 19:10 Keypad
drwxrwxr-x 5 clay clay 4096 Nov 20 22:32 QRCode
drwxrwxr-x 9 clay clay 4096 Nov 20 19:10 TFT_eSPI

and when I try to compile the example,

/home/clay/data/github.com/ricmoo/QRCode/examples/QRCode/QRCode.ino: In function 'void setup()':
QRCode:21:5: error: 'QRCode' was not declared in this scope
     QRCode qrcode;
     ^~~~~~
QRCode:22:24: error: 'qrcode_getBufferSize' was not declared in this scope

shouldn't it be able to find QRCode? If it is inappropriate to post this here and its not a bug happy to close and move the conversation.

ChatGPT proposed code, refering to function in this library, which does not exist

Hi, Code ChatGPT suggested:

String generateQRCode(const String& data) {
QRCode qrcode;
uint8_t qrcodeData[qrcode_getBufferSize(3)];
qrcode_initText(&qrcode, qrcodeData, 3, 0, data.c_str());

String qrCodeHtml = "<img src="data:image/png;base64,";
qrCodeHtml += qrcode_getQRCode(&qrcode);
qrCodeHtml += "">";

return qrCodeHtml;
}

But..."qrcode_getQRCode" is not declared in qrcode.h!:
How comes that ChatGPT thinks this is part of Richard Moore's library??

QR to Bitmap

I'm trying to create a BMP of the QR code to display on a 128x64 OLED screen like you mentioned in the readme.
Is there an example for this?

I have tried using your for loop to generate the bits, but that did not work.

Missing Alignment and finder patterns

I am using the library to plot the QR code on an monochrome 8 bit lcd display. I am able to plot the QR directly from the buffer. The code I am using is as below:


#define __width 41
#define __height 41
#define __input_size (__width +7)/8 * __width

....

int main() {
// The structure to manage the QR code
QRCode qrcode;

// Allocate a chunk of memory to store the QR code
uint8_t qrcodeBytes[qrcode_getBufferSize()];

qrcode_initText(&qrcode, qrcodeBytes, 3, ECC_LOW, "HELLO WORLD");
 ...
  for(int i=0; i<__input_size; i++){
      LCD_putByte(qrcodeBytes[i]);
     }
...
}

But the resulting QR code is not scannable and lacks finder/alignment patterns. Any guess why?

Thanks in advance

generate wifi QRCode

Hello,

Did you thinks that it's possible to generate qrCode for wifi access ?

Thanks a lot for the librarie.

Cannot build with MSVC

MSVC doesn't support VLA and #pragma mark.
Winsdk headers includes #define min/max, which generates lots of errors.
Hope for some workround.

The code consumes a significant amount of Stack and Heap memory!

I'm using this library on STM32 and Keil. I encountered an issue when trying to generate QR codes above version 8. After some experimentation, I discovered that it requires additional Heap and Stack memory.
Currently, with 12KB of Stack and 4KB of Heap memory allocated, I am able to generate QR codes up to version 13. However, for higher versions, more memory is needed, which I currently lack. I attempted to set LOCK_VERSION to 14, but it did not resolve the issue.
Is there a way to optimize memory usage and reduce consumption?

This image is for version 13 on a thermal printer.

Error code for string size not implemented in qrcode_initBytes(...)

The ability to return an error code is not implemented, see lines:
774 // @TODO: Return error if data is too big. 775 int8_t qrcode_initBytes(QRCode *qrcode, uint8_t *modules, uint8_t version, uint8_t ecc, uint8_t *data, uint16_t length) { ... 848 return 0; 849 }

cpp warning

Hi, just want to say that with my new Arduino IDE I got some warnings about constants.

This code:

uint8_t qrcodeBytes[qrcode_getBufferSize(2)];

should create a new array. But since the qrcode_getBufferSize function is not a constant, I get some warnings.

Moving the 2 functions to the header and declaring them with defines, it works like expected:

#define bb_getGridSizeBytes(_size) ((_size * _size + 7) / 8)
#define qrcode_getBufferSize(_ver) bb_getGridSizeBytes((4 * _ver + 17))

Display it to Webserver

i tried using this library and display it to website. But i dont know which one from the script that make summon the QR Code.
Can you help me ?
If i cant put it to website, can you give me an explain how to make the QR Code save to Micro SD as BMP / PNG
Thank you

hm-qrcode 二维码转换成动态二维码

Doesnt work with latest esp32 boards in Arduino IDe

Installing latest esp32 boards in Arduino IDE breaks your great library

QR to bitmap to print via Thermal Printer

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

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

QR Text being padded with 'ec 11' which doesn't allow for smaller versions.

Encoded Text: WIFI:S:*MyWifi-B0B5;T:nopass;P:;;

Encoded Bytes: 42 15 74 94 64 93 a5 33 a2 a4 d7 95 76 96 66 92 d4 23 04 23 53 b5 43 a6 e6 f7 06 17 37 33 b5 03 a3 b3 b0 ec 11 ec 11 ec 11 ec 11 ec 11 ec 11 ec 11 ec 11 ec 11 ec 11

For some reason it's padding with ec 11, which is now allowing me to use a smaller version

QR code type 10 or higher not scanable

The qr codes generated and displayed on a 320x480 TFT / Arduino MEGA can be scanned using an average qr-code scanner app, up to type 9. Using type 10 or higher, the app does not scan the code.

qrcode_initText retruns 0 (zero). Seems to be ok.

See code below, including the output: type 9 is working and type 10 is not working

Not sure if it is something I did wrong, or any other reason.
Help is greatly appreciated!

Kind regards

#include "qrcode.h"
#define LCD_CS A3 // Chip Select goes to Analog 3
#define LCD_CD A2 // Command/Data goes to Analog 2
#define LCD_WR A1 // LCD Write goes to Analog 1
#define LCD_RD A0 // LCD Read goes to Analog 0
#define LCD_RESET A4 // Can alternately just connect to Arduino's reset pin
#include <SPI.h>          // f.k. for Arduino-1.5.2
#include "Adafruit_GFX.h"// Hardware-specific library
#include <MCUFRIEND_kbv.h>
MCUFRIEND_kbv tft;
#define BLACK   0x0000
#define WHITE   0xFFFF

void setup() {
    int qr_return;
    // Create the QR code
    QRCode qrcode;
    uint8_t qrcodeData9[qrcode_getBufferSize(9)]; 
    
    qrcode_initText(&qrcode, qrcodeData9, 9, 0, "https://a.nl?b=HelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHel0123456789");
    
    uint16_t ID = tft.readID(); //
    tft.begin(ID);
    tft.fillScreen(WHITE);

    uint8_t qr_size = 5;
    uint8_t qr_top = 20;
    uint8_t qr_left = (320 / 2) - int((qrcode.size * qr_size) / 2);  // Center

    // Each line of modules
    for (uint8_t y = 0; y < qrcode.size; y++) {
        // Each horizontal module
        for (uint8_t x = 0; x < qrcode.size; x++) {
          if (qrcode_getModule(&qrcode, x, y)) {
            
            tft.fillRect(qr_left + (qr_size * x), qr_top + (qr_size * y), qr_size, qr_size, BLACK);
          }
        }
    }
   
    uint8_t qrcodeData10[qrcode_getBufferSize(10)]; 
    qrcode_initText(&qrcode, qrcodeData10, 10, 0, "https://a.nl?b=HelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHelloworldHel0123456789");

    qr_left = (320 / 2) - int((qrcode.size * qr_size) / 2);  // Center
    tft.fillScreen(WHITE);
    // Each line of modules
    for (uint8_t y = 0; y < qrcode.size; y++) {
        // Each horizontal module
        for (uint8_t x = 0; x < qrcode.size; x++) {
          if (qrcode_getModule(&qrcode, x, y)) {
            
            tft.fillRect(qr_left + (qr_size * x), qr_top + (qr_size * y), qr_size, qr_size, BLACK);
          }
        }
    }
}

void loop() {

}

Type 9 is working

Type 10 is not working

How can I put more characters on the QR code?

I am trying to put +- 100 characters on the QR code. But I am having problems, because it need to be converted on array. What type of variable can I use to storage +- 100 characters?

When I try to put a char, a erro appears: " int8_t qrcode_initText(QRCode *qrcode, uint8_t *modules, uint8_t version, uint8_t ecc, const char *data);"

`String str;
ptos ++;
ptos ++;
e = horas;
total = ptos10000 + e100 + minutos;
Serial.println(total);
Serial.print(" = ");
str = String(total);
str.toCharArray(a,160);
Serial.print(a);
Serial.print("\n");

Serial.print("\n");
// Start time
uint32_t dt = millis();

// Create the QR code
QRCode qrcode;
uint8_t qrcodeNumeric[qrcode_getBufferSize(3)];
qrcode_initText(&qrcode, qrcodeNumeric, 3, ECC_LOW, total); `

Thanks for all

Cannot scan qrcodes for version 2 and 3 with android qrdroid reader

Hello,
I want to report that I'm having issues with qr codes version 2 and 3.
I tried to scan qr code generated with this versions and qr droid for android is not able to detect them. I tried to generate qrcodes version 4 and 5 and I can scan them without any issue.
This sound strange, maybe a qr droid issue but I want to report the problem anyway to better investigate and check if other people noticed the same thing.
Thanks for this software,
Regards

Generating Data Matrix code

Hi,
Is there a way to generate a Data Matrix code from this library?
Like this one in Image.