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Merge pull request #1 from qgyhd1234/master

【添加】qrcode package
朱天龙 (Armink) 7 år sedan
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7 ändrade filer med 1141 tillägg och 0 borttagningar
  1. 52 0
      .gitignore
  2. 94 0
      README.md
  3. 14 0
      SConscript
  4. BIN
      figures/qrcode.gif
  5. 86 0
      inc/qrcode.h
  6. 56 0
      samples/qrcode_sample.c
  7. 839 0
      src/qrcode.c

+ 52 - 0
.gitignore

@@ -0,0 +1,52 @@
+# Prerequisites
+*.d
+
+# Object files
+*.o
+*.ko
+*.obj
+*.elf
+
+# Linker output
+*.ilk
+*.map
+*.exp
+
+# Precompiled Headers
+*.gch
+*.pch
+
+# Libraries
+*.lib
+*.a
+*.la
+*.lo
+
+# Shared objects (inc. Windows DLLs)
+*.dll
+*.so
+*.so.*
+*.dylib
+
+# Executables
+*.exe
+*.out
+*.app
+*.i*86
+*.x86_64
+*.hex
+
+# Debug files
+*.dSYM/
+*.su
+*.idb
+*.pdb
+
+# Kernel Module Compile Results
+*.mod*
+*.cmd
+.tmp_versions/
+modules.order
+Module.symvers
+Mkfile.old
+dkms.conf

+ 94 - 0
README.md

@@ -0,0 +1,94 @@
+# qrcode
+
+## 1、介绍
+
+**qrcode** 是一个用于将字符串生成二维码的软件包。该软件包是 **RT-Thread** 基于 [ricmoo/QRCode](https://github.com/ricmoo/QRCode) 开源库的移植。
+
+### 1.1 目录结构
+
+| 名称 | 说明 |
+| ---- | ---- |
+| examples | 例子目录,并有相应的一些说明 |
+| inc  | 头文件目录 |
+| src  | 源代码目录 |
+
+### 1.2 许可证
+
+`qrcode` 软件包延用 `QRCode` 软件包许可协议,请见 `qrcode/LICENSE` 文件。
+
+### 1.3 依赖
+
+- RT-Thread 3.0+
+
+## 2、如何打开 qrcode
+
+使用 qrcodepackage 需要在 RT-Thread 的包管理器中选择它,具体路径如下:
+
+```shell
+RT-Thread online packages
+    tools packages --->
+        [*] qrcode: A simple library for generating QR codes in C
+            [*] Enable qrcode sample
+```
+
+- `Enable qrcode sample`: 开启二维码例程;
+
+然后让 RT-Thread 的包管理器自动更新,或者使用 `pkgs --update` 命令更新包到 BSP 中。
+
+## 3、使用 qrcode
+
+### 生成二维码
+
+在使用 qrcode 软件包时首先要定义一个结构体来管理二维码,
+
+```c
+QRCode qrcode;
+```
+
+然后根据要版本号来申请动态内存,用来保存生成的二维码,
+
+```c
+uint8_t *qrcodeBytes = (uint8_t *)rt_calloc(1, qrcode_getBufferSize(DEFAULT_QR_VERSION));
+```
+
+最后使用二维码生成函数生成二维码。
+
+```c
+qrcode_initText(&qrcode, qrcodeBytes, DEFAULT_QR_VERSION, ECC_LOW, "HELLO WORLD");
+```
+
+### 打印二维码
+
+生成的二维码是点阵数据,8个点构成一个 Byte。显示二维码可以使用以下代码
+
+```c
+for (uint8 y = 0; y < qrcode.size; y++) {
+    for (uint8 x = 0; x < qrcode.size; x++) {
+        if (qrcode_getModule(&qrcode, x, y) {
+            rt_kprintf("**");
+        } else {
+            rt_kprintf("  ");
+        }
+    }
+    Serial.print("\n");
+}
+```
+
+## 4、示例演示
+
+本示例需要在 qrcode 软件包中开启二维码例程。
+
+在 MSH 中输入命令 qrcode RT-Thread,可以在串口助手上打印出一个二维码来,利用手机扫码软件扫描后可以看到结果为 RT-Thread。
+
+![qrcode](figures/qrcode.gif)
+
+## 5、注意事项
+
+- 在生成二维码时,使用的版本越高,需要申请的动态内存就越大。
+- 扫描串口助手上的二维码时,注意设置串口助手白底黑字。
+- 扫描串口助手上的二维码时,注意缩小文字显示,让*间的间距减小。
+
+## 6、联系方式 & 感谢
+
+* 维护:[qgyhd1234](https://github.com/qgyhd1234)
+* 主页:https://github.com/RT-Thread-packages/qrcode

+ 14 - 0
SConscript

@@ -0,0 +1,14 @@
+from building import *
+
+cwd  = GetCurrentDir()
+
+src = Glob('src/*.c')
+
+if GetDepend(['PKG_QRCODE_SAMPLE']):
+    src += Glob('samples/*.c')
+
+CPPPATH = [cwd + '/inc']
+
+group = DefineGroup('qrcode', src, depend = ['PKG_USING_QRCODE'], CPPPATH = CPPPATH)
+
+Return('group')

BIN
figures/qrcode.gif


+ 86 - 0
inc/qrcode.h

@@ -0,0 +1,86 @@
+/**
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2017 Richard Moore
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+/**
+ *  Special thanks to Nayuki (https://www.nayuki.io/) from which this library was
+ *  heavily inspired and compared against.
+ *
+ *  See: https://github.com/nayuki/QR-Code-generator/tree/master/cpp
+ */
+
+
+#ifndef __QRCODE_H_
+#define __QRCODE_H_
+
+#include <stdint.h>
+#include <stdbool.h>
+
+// QR Code Format Encoding
+#define MODE_NUMERIC        0
+#define MODE_ALPHANUMERIC   1
+#define MODE_BYTE           2
+
+// Error Correction Code Levels
+#define ECC_LOW            0
+#define ECC_MEDIUM         1
+#define ECC_QUARTILE       2
+#define ECC_HIGH           3
+
+
+// If set to non-zero, this library can ONLY produce QR codes at that version
+// This saves a lot of dynamic memory, as the codeword tables are skipped
+#ifndef LOCK_VERSION
+#define LOCK_VERSION       0
+#endif
+
+
+typedef struct QRCode {
+    uint8_t version;
+    uint8_t size;
+    uint8_t ecc;
+    uint8_t mode;
+    uint8_t mask;
+    uint8_t *modules;
+} QRCode;
+
+
+#ifdef __cplusplus
+extern "C"{
+#endif  /* __cplusplus */
+
+
+
+uint16_t qrcode_getBufferSize(uint8_t version);
+
+int8_t qrcode_initText(QRCode *qrcode, uint8_t *modules, uint8_t version, uint8_t ecc, const char *data);
+int8_t qrcode_initBytes(QRCode *qrcode, uint8_t *modules, uint8_t version, uint8_t ecc, uint8_t *data, uint16_t length);
+
+bool qrcode_getModule(QRCode *qrcode, uint8_t x, uint8_t y);
+
+#ifdef __cplusplus
+}
+#endif  /* __cplusplus */
+
+
+#endif  /* __QRCODE_H_ */

+ 56 - 0
samples/qrcode_sample.c

@@ -0,0 +1,56 @@
+#include <rtthread.h>
+#include "qrcode.h"
+
+#if defined(RT_USING_FINSH) && defined(FINSH_USING_MSH)
+#include <finsh.h>
+static void qrcode(uint8_t argc, char **argv)
+{
+#define DEFAULT_QR_VERSION 3
+#define DEFAULT_QR_STRING "HELLO WORLD"
+
+    QRCode qrc;
+    uint8_t x, y, *qrcodeBytes = (uint8_t *)rt_calloc(1, qrcode_getBufferSize(DEFAULT_QR_VERSION));
+    int8_t result;
+    char *qrstr = DEFAULT_QR_STRING;
+
+    if (qrcodeBytes)
+    {
+        if (argc > 1)
+        {
+            qrstr = argv[1];
+        }
+
+        result = qrcode_initText(&qrc, qrcodeBytes, DEFAULT_QR_VERSION, ECC_LOW, qrstr);
+
+        if (result >= 0)
+        {
+            rt_kprintf("\n");
+            for (y = 0; y < qrc.size; y++)
+            {
+                for (x = 0; x < qrc.size; x++)
+                {
+                    if (qrcode_getModule(&qrc, x, y))
+                    {
+                        rt_kprintf("**");
+                    }
+                    else
+                    {
+                        rt_kprintf("  ");
+                    }
+                }
+                rt_kprintf("\n");
+            }
+        }
+        else
+        {
+            rt_kprintf("QR CODE(%s) General FAILED(%d)\n", qrstr, result);
+        }
+        rt_free(qrcodeBytes);
+    }
+    else
+    {
+        rt_kprintf("Warning: no memory!\n");
+    }
+}
+MSH_CMD_EXPORT(qrcode, qrcode generator: qrcode [string]);
+#endif /* defined(RT_USING_FINSH) && defined(FINSH_USING_MSH) */

+ 839 - 0
src/qrcode.c

@@ -0,0 +1,839 @@
+/**
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2017 Richard Moore
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+/**
+ *  Special thanks to Nayuki (https://www.nayuki.io/) from which this library was
+ *  heavily inspired and compared against.
+ *
+ *  See: https://github.com/nayuki/QR-Code-generator/tree/master/cpp
+ */
+ 
+ /**
+ *  This package is RT-Thread adaptation to the QRCode library.
+ *
+ *  See: https://github.com/RT-Thread-packages/qrcode
+ */
+
+#include "qrcode.h"
+#include <rtthread.h>
+
+#define DBG_ENABLE
+#define DBG_SECTION_NAME               "qrcode"
+#define DBG_LEVEL                      DBG_LOG
+#include <rtdbg.h>
+
+#include <stdlib.h>
+#include <string.h>
+
+#if LOCK_VERSION == 0
+
+static const uint16_t NUM_ERROR_CORRECTION_CODEWORDS[4][40] = {
+    // 1,  2,  3,  4,  5,   6,   7,   8,   9,  10,  11,  12,  13,  14,  15,  16,  17,  18,  19,  20,  21,  22,  23,  24,   25,   26,   27,   28,   29,   30,   31,   32,   33,   34,   35,   36,   37,   38,   39,   40    Error correction level
+    { 10, 16, 26, 36, 48,  64,  72,  88, 110, 130, 150, 176, 198, 216, 240, 280, 308, 338, 364, 416, 442, 476, 504, 560,  588,  644,  700,  728,  784,  812,  868,  924,  980, 1036, 1064, 1120, 1204, 1260, 1316, 1372},  // Medium
+    {  7, 10, 15, 20, 26,  36,  40,  48,  60,  72,  80,  96, 104, 120, 132, 144, 168, 180, 196, 224, 224, 252, 270, 300,  312,  336,  360,  390,  420,  450,  480,  510,  540,  570,  570,  600,  630,  660,  720,  750},  // Low
+    { 17, 28, 44, 64, 88, 112, 130, 156, 192, 224, 264, 308, 352, 384, 432, 480, 532, 588, 650, 700, 750, 816, 900, 960, 1050, 1110, 1200, 1260, 1350, 1440, 1530, 1620, 1710, 1800, 1890, 1980, 2100, 2220, 2310, 2430},  // High
+    { 13, 22, 36, 52, 72,  96, 108, 132, 160, 192, 224, 260, 288, 320, 360, 408, 448, 504, 546, 600, 644, 690, 750, 810,  870,  952, 1020, 1050, 1140, 1200, 1290, 1350, 1440, 1530, 1590, 1680, 1770, 1860, 1950, 2040},  // Quartile
+};
+
+static const uint8_t NUM_ERROR_CORRECTION_BLOCKS[4][40] = {
+    // Version: (note that index 0 is for padding, and is set to an illegal value)
+    // 1, 2, 3, 4, 5, 6, 7, 8, 9,10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40    Error correction level
+    {  1, 1, 1, 2, 2, 4, 4, 4, 5, 5,  5,  8,  9,  9, 10, 10, 11, 13, 14, 16, 17, 17, 18, 20, 21, 23, 25, 26, 28, 29, 31, 33, 35, 37, 38, 40, 43, 45, 47, 49},  // Medium
+    {  1, 1, 1, 1, 1, 2, 2, 2, 2, 4,  4,  4,  4,  4,  6,  6,  6,  6,  7,  8,  8,  9,  9, 10, 12, 12, 12, 13, 14, 15, 16, 17, 18, 19, 19, 20, 21, 22, 24, 25},  // Low
+    {  1, 1, 2, 4, 4, 4, 5, 6, 8, 8, 11, 11, 16, 16, 18, 16, 19, 21, 25, 25, 25, 34, 30, 32, 35, 37, 40, 42, 45, 48, 51, 54, 57, 60, 63, 66, 70, 74, 77, 81},  // High
+    {  1, 1, 2, 2, 4, 4, 6, 6, 8, 8,  8, 10, 12, 16, 12, 17, 16, 18, 21, 20, 23, 23, 25, 27, 29, 34, 34, 35, 38, 40, 43, 45, 48, 51, 53, 56, 59, 62, 65, 68},  // Quartile
+};
+
+static const uint16_t NUM_RAW_DATA_MODULES[40] = {
+    //  1,   2,   3,   4,    5,    6,    7,    8,    9,   10,   11,   12,   13,   14,   15,   16,   17,
+      208, 359, 567, 807, 1079, 1383, 1568, 1936, 2336, 2768, 3232, 3728, 4256, 4651, 5243, 5867, 6523,
+    //   18,   19,   20,   21,    22,    23,    24,    25,   26,    27,     28,    29,    30,    31,
+       7211, 7931, 8683, 9252, 10068, 10916, 11796, 12708, 13652, 14628, 15371, 16411, 17483, 18587,
+    //    32,    33,    34,    35,    36,    37,    38,    39,    40
+       19723, 20891, 22091, 23008, 24272, 25568, 26896, 28256, 29648
+};
+
+// @TODO: Put other LOCK_VERSIONS here
+#elif LOCK_VERSION == 3
+
+static const int16_t NUM_ERROR_CORRECTION_CODEWORDS[4] = {
+    26, 15, 44, 36
+};
+
+static const int8_t NUM_ERROR_CORRECTION_BLOCKS[4] = {
+    1, 1, 2, 2
+};
+
+static const uint16_t NUM_RAW_DATA_MODULES = 567;
+
+#else
+
+#error Unsupported LOCK_VERSION (add it...)
+
+#endif
+
+static int max(int a, int b) {
+    if (a > b) { return a; }
+    return b;
+}
+
+static int8_t getAlphanumeric(char c) {
+    
+    if (c >= '0' && c <= '9') { return (c - '0'); }
+    if (c >= 'A' && c <= 'Z') { return (c - 'A' + 10); }
+    
+    switch (c) {
+        case ' ': return 36;
+        case '$': return 37;
+        case '%': return 38;
+        case '*': return 39;
+        case '+': return 40;
+        case '-': return 41;
+        case '.': return 42;
+        case '/': return 43;
+        case ':': return 44;
+    }
+    
+    return -1;
+}
+
+static bool isAlphanumeric(const char *text, uint16_t length) {
+    while (length != 0) {
+        if (getAlphanumeric(text[--length]) == -1) { return false; }
+    }
+    return true;
+}
+
+static bool isNumeric(const char *text, uint16_t length) {
+    while (length != 0) {
+        char c = text[--length];
+        if (c < '0' || c > '9') { return false; }
+    }
+    return true;
+}
+
+// We store the following tightly packed (less 8) in modeInfo
+//               <=9  <=26  <= 40
+// NUMERIC      ( 10,   12,    14);
+// ALPHANUMERIC (  9,   11,    13);
+// BYTE         (  8,   16,    16);
+static char getModeBits(uint8_t version, uint8_t mode) {
+    // Note: We use 15 instead of 16; since 15 doesn't exist and we cannot store 16 (8 + 8) in 3 bits
+    // hex(int("".join(reversed([('00' + bin(x - 8)[2:])[-3:] for x in [10, 9, 8, 12, 11, 15, 14, 13, 15]])), 2))
+    unsigned int modeInfo = 0x7bbb80a;
+    
+#if LOCK_VERSION == 0 || LOCK_VERSION > 9
+    if (version > 9) { modeInfo >>= 9; }
+#endif
+    
+#if LOCK_VERSION == 0 || LOCK_VERSION > 26
+    if (version > 26) { modeInfo >>= 9; }
+#endif
+    
+    char result = 8 + ((modeInfo >> (3 * mode)) & 0x07);
+    if (result == 15) { result = 16; }
+    
+    return result;
+}
+
+typedef struct BitBucket {
+    uint32_t bitOffsetOrWidth;
+    uint16_t capacityBytes;
+    uint8_t *data;
+} BitBucket;
+
+static uint16_t bb_getGridSizeBytes(uint8_t size) {
+    return (((size * size) + 7) / 8);
+}
+
+static uint16_t bb_getBufferSizeBytes(uint32_t bits) {
+    return ((bits + 7) / 8);
+}
+
+static void bb_initBuffer(BitBucket *bitBuffer, uint8_t *data, int32_t capacityBytes) {
+    bitBuffer->bitOffsetOrWidth = 0;
+    bitBuffer->capacityBytes = capacityBytes;
+    bitBuffer->data = data;
+    
+    memset(data, 0, bitBuffer->capacityBytes);
+}
+
+static void bb_initGrid(BitBucket *bitGrid, uint8_t *data, uint8_t size) {
+    bitGrid->bitOffsetOrWidth = size;
+    bitGrid->capacityBytes = bb_getGridSizeBytes(size);
+    bitGrid->data = data;
+
+    memset(data, 0, bitGrid->capacityBytes);
+}
+
+static void bb_appendBits(BitBucket *bitBuffer, uint32_t val, uint8_t length) {
+    uint32_t offset = bitBuffer->bitOffsetOrWidth;
+    for (int8_t i = length - 1; i >= 0; i--, offset++) {
+        bitBuffer->data[offset >> 3] |= ((val >> i) & 1) << (7 - (offset & 7));
+    }
+    bitBuffer->bitOffsetOrWidth = offset;
+}
+
+static void bb_setBit(BitBucket *bitGrid, uint8_t x, uint8_t y, bool on) {
+    uint32_t offset = y * bitGrid->bitOffsetOrWidth + x;
+    uint8_t mask = 1 << (7 - (offset & 0x07));
+    if (on) {
+        bitGrid->data[offset >> 3] |= mask;
+    } else {
+        bitGrid->data[offset >> 3] &= ~mask;
+    }
+}
+
+static void bb_invertBit(BitBucket *bitGrid, uint8_t x, uint8_t y, bool invert) {
+    uint32_t offset = y * bitGrid->bitOffsetOrWidth + x;
+    uint8_t mask = 1 << (7 - (offset & 0x07));
+    bool on = ((bitGrid->data[offset >> 3] & (1 << (7 - (offset & 0x07)))) != 0);
+    if (on ^ invert) {
+        bitGrid->data[offset >> 3] |= mask;
+    } else {
+        bitGrid->data[offset >> 3] &= ~mask;
+    }
+}
+
+static bool bb_getBit(BitBucket *bitGrid, uint8_t x, uint8_t y) {
+    uint32_t offset = y * bitGrid->bitOffsetOrWidth + x;
+    return (bitGrid->data[offset >> 3] & (1 << (7 - (offset & 0x07)))) != 0;
+}
+
+// XORs the data modules in this QR Code with the given mask pattern. Due to XOR's mathematical
+// properties, calling applyMask(m) twice with the same value is equivalent to no change at all.
+// This means it is possible to apply a mask, undo it, and try another mask. Note that a final
+// well-formed QR Code symbol needs exactly one mask applied (not zero, not two, etc.).
+static void applyMask(BitBucket *modules, BitBucket *isFunction, uint8_t mask) {
+    uint8_t size = modules->bitOffsetOrWidth;
+    
+    for (uint8_t y = 0; y < size; y++) {
+        for (uint8_t x = 0; x < size; x++) {
+            if (bb_getBit(isFunction, x, y)) { continue; }
+            
+            bool invert = 0;
+            switch (mask) {
+                case 0:  invert = (x + y) % 2 == 0;                    break;
+                case 1:  invert = y % 2 == 0;                          break;
+                case 2:  invert = x % 3 == 0;                          break;
+                case 3:  invert = (x + y) % 3 == 0;                    break;
+                case 4:  invert = (x / 3 + y / 2) % 2 == 0;            break;
+                case 5:  invert = x * y % 2 + x * y % 3 == 0;          break;
+                case 6:  invert = (x * y % 2 + x * y % 3) % 2 == 0;    break;
+                case 7:  invert = ((x + y) % 2 + x * y % 3) % 2 == 0;  break;
+            }
+            bb_invertBit(modules, x, y, invert);
+        }
+    }
+}
+
+static void setFunctionModule(BitBucket *modules, BitBucket *isFunction, uint8_t x, uint8_t y, bool on) {
+    bb_setBit(modules, x, y, on);
+    bb_setBit(isFunction, x, y, true);
+}
+
+// Draws a 9*9 finder pattern including the border separator, with the center module at (x, y).
+static void drawFinderPattern(BitBucket *modules, BitBucket *isFunction, uint8_t x, uint8_t y) {
+    uint8_t size = modules->bitOffsetOrWidth;
+
+    for (int8_t i = -4; i <= 4; i++) {
+        for (int8_t j = -4; j <= 4; j++) {
+            uint8_t dist = max(abs(i), abs(j));  // Chebyshev/infinity norm
+            int16_t xx = x + j, yy = y + i;
+            if (0 <= xx && xx < size && 0 <= yy && yy < size) {
+                setFunctionModule(modules, isFunction, xx, yy, dist != 2 && dist != 4);
+            }
+        }
+    }
+}
+
+// Draws a 5*5 alignment pattern, with the center module at (x, y).
+static void drawAlignmentPattern(BitBucket *modules, BitBucket *isFunction, uint8_t x, uint8_t y) {
+    for (int8_t i = -2; i <= 2; i++) {
+        for (int8_t j = -2; j <= 2; j++) {
+            setFunctionModule(modules, isFunction, x + j, y + i, max(abs(i), abs(j)) != 1);
+        }
+    }
+}
+
+// Draws two copies of the format bits (with its own error correction code)
+// based on the given mask and this object's error correction level field.
+static void drawFormatBits(BitBucket *modules, BitBucket *isFunction, uint8_t ecc, uint8_t mask) {
+    
+    uint8_t size = modules->bitOffsetOrWidth;
+
+    // Calculate error correction code and pack bits
+    uint32_t data = ecc << 3 | mask;  // errCorrLvl is uint2, mask is uint3
+    uint32_t rem = data;
+    for (int i = 0; i < 10; i++) {
+        rem = (rem << 1) ^ ((rem >> 9) * 0x537);
+    }
+    
+    data = data << 10 | rem;
+    data ^= 0x5412;  // uint15
+    
+    // Draw first copy
+    for (uint8_t i = 0; i <= 5; i++) {
+        setFunctionModule(modules, isFunction, 8, i, ((data >> i) & 1) != 0);
+    }
+    
+    setFunctionModule(modules, isFunction, 8, 7, ((data >> 6) & 1) != 0);
+    setFunctionModule(modules, isFunction, 8, 8, ((data >> 7) & 1) != 0);
+    setFunctionModule(modules, isFunction, 7, 8, ((data >> 8) & 1) != 0);
+    
+    for (int8_t i = 9; i < 15; i++) {
+        setFunctionModule(modules, isFunction, 14 - i, 8, ((data >> i) & 1) != 0);
+    }
+    
+    // Draw second copy
+    for (int8_t i = 0; i <= 7; i++) {
+        setFunctionModule(modules, isFunction, size - 1 - i, 8, ((data >> i) & 1) != 0);
+    }
+    
+    for (int8_t i = 8; i < 15; i++) {
+        setFunctionModule(modules, isFunction, 8, size - 15 + i, ((data >> i) & 1) != 0);
+    }
+    
+    setFunctionModule(modules, isFunction, 8, size - 8, true);
+}
+
+// Draws two copies of the version bits (with its own error correction code),
+// based on this object's version field (which only has an effect for 7 <= version <= 40).
+static void drawVersion(BitBucket *modules, BitBucket *isFunction, uint8_t version) {
+    
+    int8_t size = modules->bitOffsetOrWidth;
+
+#if LOCK_VERSION != 0 && LOCK_VERSION < 7
+    return;
+    
+#else
+    if (version < 7) { return; }
+    
+    // Calculate error correction code and pack bits
+    uint32_t rem = version;  // version is uint6, in the range [7, 40]
+    for (uint8_t i = 0; i < 12; i++) {
+        rem = (rem << 1) ^ ((rem >> 11) * 0x1F25);
+    }
+    
+    uint32_t data = version << 12 | rem;  // uint18
+    
+    // Draw two copies
+    for (uint8_t i = 0; i < 18; i++) {
+        bool bit = ((data >> i) & 1) != 0;
+        uint8_t a = size - 11 + i % 3, b = i / 3;
+        setFunctionModule(modules, isFunction, a, b, bit);
+        setFunctionModule(modules, isFunction, b, a, bit);
+    }
+    
+#endif
+}
+
+static void drawFunctionPatterns(BitBucket *modules, BitBucket *isFunction, uint8_t version, uint8_t ecc) {
+    
+    uint8_t size = modules->bitOffsetOrWidth;
+
+    // Draw the horizontal and vertical timing patterns
+    for (uint8_t i = 0; i < size; i++) {
+        setFunctionModule(modules, isFunction, 6, i, i % 2 == 0);
+        setFunctionModule(modules, isFunction, i, 6, i % 2 == 0);
+    }
+    
+    // Draw 3 finder patterns (all corners except bottom right; overwrites some timing modules)
+    drawFinderPattern(modules, isFunction, 3, 3);
+    drawFinderPattern(modules, isFunction, size - 4, 3);
+    drawFinderPattern(modules, isFunction, 3, size - 4);
+    
+#if LOCK_VERSION == 0 || LOCK_VERSION > 1
+
+    if (version > 1) {
+
+        // Draw the numerous alignment patterns
+        
+        uint8_t alignCount = version / 7 + 2;
+        uint8_t step;
+        if (version != 32) {
+            step = (version * 4 + alignCount * 2 + 1) / (2 * alignCount - 2) * 2;  // ceil((size - 13) / (2*numAlign - 2)) * 2
+        } else { // C-C-C-Combo breaker!
+            step = 26;
+        }
+        
+        uint8_t alignPositionIndex = alignCount - 1;
+        uint8_t *alignPosition = (uint8_t *)rt_calloc(1, alignCount);
+        if (!alignPosition) {
+            LOG_W("No Memory");
+            return;
+        }
+        
+        alignPosition[0] = 6;
+        
+        uint8_t size = version * 4 + 17;
+        for (uint8_t i = 0, pos = size - 7; i < alignCount - 1; i++, pos -= step) {
+            alignPosition[alignPositionIndex--] = pos;
+        }
+        
+        for (uint8_t i = 0; i < alignCount; i++) {
+            for (uint8_t j = 0; j < alignCount; j++) {
+                if ((i == 0 && j == 0) || (i == 0 && j == alignCount - 1) || (i == alignCount - 1 && j == 0)) {
+                    continue;  // Skip the three finder corners
+                } else {
+                    drawAlignmentPattern(modules, isFunction, alignPosition[i], alignPosition[j]);
+                }
+            }
+        }
+        rt_free(alignPosition);
+}
+    
+#endif
+    
+    // Draw configuration data
+    drawFormatBits(modules, isFunction, ecc, 0);  // Dummy mask value; overwritten later in the constructor
+    drawVersion(modules, isFunction, version);
+}
+
+
+// Draws the given sequence of 8-bit codewords (data and error correction) onto the entire
+// data area of this QR Code symbol. Function modules need to be marked off before this is called.
+static void drawCodewords(BitBucket *modules, BitBucket *isFunction, BitBucket *codewords) {
+    
+    uint32_t bitLength = codewords->bitOffsetOrWidth;
+    uint8_t *data = codewords->data;
+    
+    uint8_t size = modules->bitOffsetOrWidth;
+    
+    // Bit index into the data
+    uint32_t i = 0;
+    
+    // Do the funny zigzag scan
+    for (int16_t right = size - 1; right >= 1; right -= 2) {  // Index of right column in each column pair
+        if (right == 6) { right = 5; }
+        
+        for (uint8_t vert = 0; vert < size; vert++) {  // Vertical counter
+            for (int j = 0; j < 2; j++) {
+                uint8_t x = right - j;  // Actual x coordinate
+                bool upwards = ((right & 2) == 0) ^ (x < 6);
+                uint8_t y = upwards ? size - 1 - vert : vert;  // Actual y coordinate
+                if (!bb_getBit(isFunction, x, y) && i < bitLength) {
+                    bb_setBit(modules, x, y, ((data[i >> 3] >> (7 - (i & 7))) & 1) != 0);
+                    i++;
+                }
+                // If there are any remainder bits (0 to 7), they are already
+                // set to 0/false/white when the grid of modules was initialized
+            }
+        }
+    }
+}
+
+#define PENALTY_N1      3
+#define PENALTY_N2      3
+#define PENALTY_N3     40
+#define PENALTY_N4     10
+
+// Calculates and returns the penalty score based on state of this QR Code's current modules.
+// This is used by the automatic mask choice algorithm to find the mask pattern that yields the lowest score.
+// @TODO: This can be optimized by working with the bytes instead of bits.
+static uint32_t getPenaltyScore(BitBucket *modules) {
+    uint32_t result = 0;
+    
+    uint8_t size = modules->bitOffsetOrWidth;
+    
+    // Adjacent modules in row having same color
+    for (uint8_t y = 0; y < size; y++) {
+        
+        bool colorX = bb_getBit(modules, 0, y);
+        for (uint8_t x = 1, runX = 1; x < size; x++) {
+            bool cx = bb_getBit(modules, x, y);
+            if (cx != colorX) {
+                colorX = cx;
+                runX = 1;
+                
+            } else {
+                runX++;
+                if (runX == 5) {
+                    result += PENALTY_N1;
+                } else if (runX > 5) {
+                    result++;
+                }
+            }
+        }
+    }
+    
+    // Adjacent modules in column having same color
+    for (uint8_t x = 0; x < size; x++) {
+        bool colorY = bb_getBit(modules, x, 0);
+        for (uint8_t y = 1, runY = 1; y < size; y++) {
+            bool cy = bb_getBit(modules, x, y);
+            if (cy != colorY) {
+                colorY = cy;
+                runY = 1;
+            } else {
+                runY++;
+                if (runY == 5) {
+                    result += PENALTY_N1;
+                } else if (runY > 5) {
+                    result++;
+                }
+            }
+        }
+    }
+    
+    uint16_t black = 0;
+    for (uint8_t y = 0; y < size; y++) {
+        uint16_t bitsRow = 0, bitsCol = 0;
+        for (uint8_t x = 0; x < size; x++) {
+            bool color = bb_getBit(modules, x, y);
+
+            // 2*2 blocks of modules having same color
+            if (x > 0 && y > 0) {
+                bool colorUL = bb_getBit(modules, x - 1, y - 1);
+                bool colorUR = bb_getBit(modules, x, y - 1);
+                bool colorL = bb_getBit(modules, x - 1, y);
+                if (color == colorUL && color == colorUR && color == colorL) {
+                    result += PENALTY_N2;
+                }
+            }
+
+            // Finder-like pattern in rows and columns
+            bitsRow = ((bitsRow << 1) & 0x7FF) | color;
+            bitsCol = ((bitsCol << 1) & 0x7FF) | bb_getBit(modules, y, x);
+
+            // Needs 11 bits accumulated
+            if (x >= 10) {
+                if (bitsRow == 0x05D || bitsRow == 0x5D0) {
+                    result += PENALTY_N3;
+                }
+                if (bitsCol == 0x05D || bitsCol == 0x5D0) {
+                    result += PENALTY_N3;
+                }
+            }
+
+            // Balance of black and white modules
+            if (color) { black++; }
+        }
+    }
+
+    // Find smallest k such that (45-5k)% <= dark/total <= (55+5k)%
+    uint16_t total = size * size;
+    for (uint16_t k = 0; black * 20 < (9 - k) * total || black * 20 > (11 + k) * total; k++) {
+        result += PENALTY_N4;
+    }
+    
+    return result;
+}
+
+static uint8_t rs_multiply(uint8_t x, uint8_t y) {
+    // Russian peasant multiplication
+    // See: https://en.wikipedia.org/wiki/Ancient_Egyptian_multiplication
+    uint16_t z = 0;
+    for (int8_t i = 7; i >= 0; i--) {
+        z = (z << 1) ^ ((z >> 7) * 0x11D);
+        z ^= ((y >> i) & 1) * x;
+    }
+    return z;
+}
+
+static void rs_init(uint8_t degree, uint8_t *coeff) {
+    memset(coeff, 0, degree);
+    coeff[degree - 1] = 1;
+    
+    // Compute the product polynomial (x - r^0) * (x - r^1) * (x - r^2) * ... * (x - r^{degree-1}),
+    // drop the highest term, and store the rest of the coefficients in order of descending powers.
+    // Note that r = 0x02, which is a generator element of this field GF(2^8/0x11D).
+    uint16_t root = 1;
+    for (uint8_t i = 0; i < degree; i++) {
+        // Multiply the current product by (x - r^i)
+        for (uint8_t j = 0; j < degree; j++) {
+            coeff[j] = rs_multiply(coeff[j], root);
+            if (j + 1 < degree) {
+                coeff[j] ^= coeff[j + 1];
+            }
+        }
+        root = (root << 1) ^ ((root >> 7) * 0x11D);  // Multiply by 0x02 mod GF(2^8/0x11D)
+    }
+}
+
+static void rs_getRemainder(uint8_t degree, uint8_t *coeff, uint8_t *data, uint8_t length, uint8_t *result, uint8_t stride) {
+    // Compute the remainder by performing polynomial division
+    
+    //for (uint8_t i = 0; i < degree; i++) { result[] = 0; }
+    //memset(result, 0, degree);
+    
+    for (uint8_t i = 0; i < length; i++) {
+        uint8_t factor = data[i] ^ result[0];
+        for (uint8_t j = 1; j < degree; j++) {
+            result[(j - 1) * stride] = result[j * stride];
+        }
+        result[(degree - 1) * stride] = 0;
+        
+        for (uint8_t j = 0; j < degree; j++) {
+            result[j * stride] ^= rs_multiply(coeff[j], factor);
+        }
+    }
+}
+
+static int8_t encodeDataCodewords(BitBucket *dataCodewords, const uint8_t *text, uint16_t length, uint8_t version) {
+    int8_t mode = MODE_BYTE;
+    
+    if (isNumeric((char*)text, length)) {
+        mode = MODE_NUMERIC;
+        bb_appendBits(dataCodewords, 1 << MODE_NUMERIC, 4);
+        bb_appendBits(dataCodewords, length, getModeBits(version, MODE_NUMERIC));
+
+        uint16_t accumData = 0;
+        uint8_t accumCount = 0;
+        for (uint16_t i = 0; i < length; i++) {
+            accumData = accumData * 10 + ((char)(text[i]) - '0');
+            accumCount++;
+            if (accumCount == 3) {
+                bb_appendBits(dataCodewords, accumData, 10);
+                accumData = 0;
+                accumCount = 0;
+            }
+        }
+        
+        // 1 or 2 digits remaining
+        if (accumCount > 0) {
+            bb_appendBits(dataCodewords, accumData, accumCount * 3 + 1);
+        }
+        
+    } else if (isAlphanumeric((char*)text, length)) {
+        mode = MODE_ALPHANUMERIC;
+        bb_appendBits(dataCodewords, 1 << MODE_ALPHANUMERIC, 4);
+        bb_appendBits(dataCodewords, length, getModeBits(version, MODE_ALPHANUMERIC));
+
+        uint16_t accumData = 0;
+        uint8_t accumCount = 0;
+        for (uint16_t i = 0; i  < length; i++) {
+            accumData = accumData * 45 + getAlphanumeric((char)(text[i]));
+            accumCount++;
+            if (accumCount == 2) {
+                bb_appendBits(dataCodewords, accumData, 11);
+                accumData = 0;
+                accumCount = 0;
+            }
+        }
+        
+        // 1 character remaining
+        if (accumCount > 0) {
+            bb_appendBits(dataCodewords, accumData, 6);
+        }
+        
+    } else {
+        bb_appendBits(dataCodewords, 1 << MODE_BYTE, 4);
+        bb_appendBits(dataCodewords, length, getModeBits(version, MODE_BYTE));
+        for (uint16_t i = 0; i < length; i++) {
+            bb_appendBits(dataCodewords, (char)(text[i]), 8);
+        }
+    }
+    
+    //bb_setBits(dataCodewords, length, 4, getModeBits(version, mode));
+    
+    return mode;
+}
+
+static void performErrorCorrection(uint8_t version, uint8_t ecc, BitBucket *data) {
+    
+    // See: http://www.thonky.com/qr-code-tutorial/structure-final-message
+    
+#if LOCK_VERSION == 0
+    uint8_t numBlocks = NUM_ERROR_CORRECTION_BLOCKS[ecc][version - 1];
+    uint16_t totalEcc = NUM_ERROR_CORRECTION_CODEWORDS[ecc][version - 1];
+    uint16_t moduleCount = NUM_RAW_DATA_MODULES[version - 1];
+#else
+    uint8_t numBlocks = NUM_ERROR_CORRECTION_BLOCKS[ecc];
+    uint16_t totalEcc = NUM_ERROR_CORRECTION_CODEWORDS[ecc];
+    uint16_t moduleCount = NUM_RAW_DATA_MODULES;
+#endif
+    
+    uint8_t blockEccLen = totalEcc / numBlocks;
+    uint8_t numShortBlocks = numBlocks - moduleCount / 8 % numBlocks;
+    uint8_t shortBlockLen = moduleCount / 8 / numBlocks;
+    
+    uint8_t shortDataBlockLen = shortBlockLen - blockEccLen;
+
+    uint8_t *result = (uint8_t *)rt_calloc(1, data->capacityBytes);
+    uint8_t *coeff = (uint8_t *)rt_calloc(1, blockEccLen);
+    if (!result || !coeff) {
+        LOG_W("No Memory");
+        rt_free(result);
+        rt_free(coeff);
+        return;
+    }
+    rs_init(blockEccLen, coeff);
+
+    uint16_t offset = 0;
+    uint8_t *dataBytes = data->data;
+
+    // Interleave all short blocks
+    for (uint8_t i = 0; i < shortDataBlockLen; i++) {
+        uint16_t index = i;
+        uint8_t stride = shortDataBlockLen;
+        for (uint8_t blockNum = 0; blockNum < numBlocks; blockNum++) {
+            result[offset++] = dataBytes[index];
+            
+#if LOCK_VERSION == 0 || LOCK_VERSION >= 5
+            if (blockNum == numShortBlocks) { stride++; }
+#endif
+            index += stride;
+        }
+    }
+    
+    // Version less than 5 only have short blocks
+#if LOCK_VERSION == 0 || LOCK_VERSION >= 5
+    {
+        // Interleave long blocks
+        uint16_t index = shortDataBlockLen * (numShortBlocks + 1);
+        uint8_t stride = shortDataBlockLen;
+        for (uint8_t blockNum = 0; blockNum < numBlocks - numShortBlocks; blockNum++) {
+            result[offset++] = dataBytes[index];
+            
+            if (blockNum == 0) { stride++; }
+            index += stride;
+        }
+    }
+#endif
+    
+    // Add all ecc blocks, interleaved
+    uint8_t blockSize = shortDataBlockLen;
+    for (uint8_t blockNum = 0; blockNum < numBlocks; blockNum++) {
+        
+#if LOCK_VERSION == 0 || LOCK_VERSION >= 5
+        if (blockNum == numShortBlocks) { blockSize++; }
+#endif
+        rs_getRemainder(blockEccLen, coeff, dataBytes, blockSize, &result[offset + blockNum], numBlocks);
+        dataBytes += blockSize;
+    }
+    
+    memcpy(data->data, result, data->capacityBytes);
+    data->bitOffsetOrWidth = moduleCount;
+
+    rt_free(result);
+    rt_free(coeff);
+}
+
+// We store the Format bits tightly packed into a single byte (each of the 4 modes is 2 bits)
+// The format bits can be determined by ECC_FORMAT_BITS >> (2 * ecc)
+static const uint8_t ECC_FORMAT_BITS = (0x02 << 6) | (0x03 << 4) | (0x00 << 2) | (0x01 << 0);
+
+uint16_t qrcode_getBufferSize(uint8_t version) {
+    return bb_getGridSizeBytes(4 * version + 17);
+}
+
+// @TODO: Return error if data is too big.
+int8_t qrcode_initBytes(QRCode *qrcode, uint8_t *modules, uint8_t version, uint8_t ecc, uint8_t *data, uint16_t length) {
+    uint8_t size = version * 4 + 17;
+    qrcode->version = version;
+    qrcode->size = size;
+    qrcode->ecc = ecc;
+    qrcode->modules = modules;
+    
+    uint8_t eccFormatBits = (ECC_FORMAT_BITS >> (2 * ecc)) & 0x03;
+    
+#if LOCK_VERSION == 0
+    uint16_t moduleCount = NUM_RAW_DATA_MODULES[version - 1];
+    uint16_t dataCapacity = moduleCount / 8 - NUM_ERROR_CORRECTION_CODEWORDS[eccFormatBits][version - 1];
+#else
+    version = LOCK_VERSION;
+    uint16_t moduleCount = NUM_RAW_DATA_MODULES;
+    uint16_t dataCapacity = moduleCount / 8 - NUM_ERROR_CORRECTION_CODEWORDS[eccFormatBits];
+#endif
+    
+    struct BitBucket codewords;
+    uint8_t *codewordBytes = (uint8_t *)rt_calloc(1, bb_getBufferSizeBytes(moduleCount));
+    if (!codewordBytes) {
+        LOG_W("No Memory");
+        return -RT_ENOMEM;
+    }
+    bb_initBuffer(&codewords, codewordBytes, (int32_t)bb_getBufferSizeBytes(moduleCount));
+
+    // Place the data code words into the buffer
+    int8_t mode = encodeDataCodewords(&codewords, data, length, version);
+    
+    if (mode < 0) { return -1; }
+    qrcode->mode = mode;
+    
+    // Add terminator and pad up to a byte if applicable
+    uint32_t padding = (dataCapacity * 8) - codewords.bitOffsetOrWidth;
+    if (padding > 4) { padding = 4; }
+    bb_appendBits(&codewords, 0, padding);
+    bb_appendBits(&codewords, 0, (8 - codewords.bitOffsetOrWidth % 8) % 8);
+
+    // Pad with alternate bytes until data capacity is reached
+    for (uint8_t padByte = 0xEC; codewords.bitOffsetOrWidth < (dataCapacity * 8); padByte ^= 0xEC ^ 0x11) {
+        bb_appendBits(&codewords, padByte, 8);
+    }
+
+    BitBucket modulesGrid;
+    bb_initGrid(&modulesGrid, modules, size);
+    
+    BitBucket isFunctionGrid;
+    uint8_t *isFunctionGridBytes = (uint8_t *)rt_calloc(1, bb_getGridSizeBytes(size));
+    if (!isFunctionGridBytes) {
+        LOG_W("No Memory");
+        return -RT_ENOMEM;
+    }
+    bb_initGrid(&isFunctionGrid, isFunctionGridBytes, size);
+
+    drawFunctionPatterns(&modulesGrid, &isFunctionGrid, version, eccFormatBits);
+    performErrorCorrection(version, eccFormatBits, &codewords);
+    drawCodewords(&modulesGrid, &isFunctionGrid, &codewords);
+    
+    // Find the best (lowest penalty) mask
+    uint8_t mask = 0;
+    int32_t minPenalty = INT32_MAX;
+    for (uint8_t i = 0; i < 8; i++) {
+        drawFormatBits(&modulesGrid, &isFunctionGrid, eccFormatBits, i);
+        applyMask(&modulesGrid, &isFunctionGrid, i);
+        int penalty = getPenaltyScore(&modulesGrid);
+        if (penalty < minPenalty) {
+            mask = i;
+            minPenalty = penalty;
+        }
+        applyMask(&modulesGrid, &isFunctionGrid, i);  // Undoes the mask due to XOR
+    }
+    
+    qrcode->mask = mask;
+    
+    // Overwrite old format bits
+    drawFormatBits(&modulesGrid, &isFunctionGrid, eccFormatBits, mask);
+
+    // Apply the final choice of mask
+    applyMask(&modulesGrid, &isFunctionGrid, mask);
+
+    rt_free(isFunctionGridBytes);
+    rt_free(codewordBytes);
+    return 0;
+}
+
+int8_t qrcode_initText(QRCode *qrcode, uint8_t *modules, uint8_t version, uint8_t ecc, const char *data) {
+    return qrcode_initBytes(qrcode, modules, version, ecc, (uint8_t*)data, strlen(data));
+}
+
+bool qrcode_getModule(QRCode *qrcode, uint8_t x, uint8_t y) {
+    if (x < 0 || x >= qrcode->size || y < 0 || y >= qrcode->size) {
+        return false;
+    }
+
+    uint32_t offset = y * qrcode->size + x;
+    return (qrcode->modules[offset >> 3] & (1 << (7 - (offset & 0x07)))) != 0;
+}