之前電腦上存了很多自己寫的關於arduino的有趣的小demo，因為重裝了系統，不小心誤刪了所有的文件(氣的半死)，所以現在准備一有空就重寫一下之前寫過的東東，順帶再溫習一次，這次總不能再刪了吧，嘿嘿。
這次主要想記錄一下點陣的使用，方便以后查閱，也分享出來和伙伴們一起學習進步。這次在代碼中，用的最多的就是指針的使用，就當回顧知識點了。
用到的材料：一個16*16點陣（由4塊8*8的led點陣組成的），arduino的uno。
用到的庫文件：LedControl.h ，因為點陣是使用的max7219，這個庫很不錯。
先看看效果，下面是視頻鏈接：
下面直接上代碼，有興趣的小伙伴可以玩玩。
1 #include <LedControl.h> 2 const int DIN = 12; 3 const int CLK = 10; 4 const int CS = 11; 5 int maxLen;//字的總個數 6 int row;//縱向移動數組的行數 7 int col;//橫向移動數組的列數 8 //自定義函數 9 void showWordByArr(LedControl led, byte[][2]); //通過數組顯示 10 void showWordByPtr(LedControl led, byte(*word)[2]); //通過數組指針顯示 11 void showWords(LedControl led, byte(*words)[16][2]); //顯示一組文字 12 void showTopMoveWords(LedControl led, byte(*words)[16][2]); //向上移動顯示文字 13 void showLeftMoveWords(LedControl led, byte(*words)[16][2]); //向左移動顯示文字 14 15 //初始化對象，每個對象最多可以操作8個設備(超過8個設備就再創建一個對象)。 16 LedControl led = LedControl(DIN, CLK, CS , 4);//我這里是4塊8*8的led點陣，所以設備數量填4(最大為8)。 17 byte a[][2] = //實心五角星 18 { 19 0x01, 0x00, //第一，二個設備 20 0x01, 0x00, 21 0x03, 0x80, 22 0x03, 0x80, 23 0x03, 0x80, 24 0x07, 0xC0, 25 0xFF, 0xFE, 26 0x7F, 0xFC, 27 0x3F, 0xF8, //第三，四個設備 28 0x0F, 0xE0, 29 0x0F, 0xE0, 30 0x1F, 0xF0, 31 0x1E, 0xF0, 32 0x18, 0x30, 33 0x20, 0x08, 34 0x00, 0x00 35 }; 36 byte b[][2] = //空心五角星 37 { 38 0x01, 0x00, 0x01, 0x00, 0x02, 0x80, 0x02, 0x80, 0x02, 0x80, 0x04, 0x40, 0xFC, 0x7E, 0x40, 0x04, 39 0x30, 0x18, 0x08, 0x20, 0x08, 0x20, 0x11, 0x90, 0x16, 0x50, 0x18, 0x30, 0x20, 0x08, 0x00, 0x00 40 }; 41 byte c[][2] = //空心取反 42 { 43 0xFE, 0xFF, 0xFE, 0xFF, 0xFC, 0x7F, 0xFC, 0x7F, 0xFC, 0x7F, 0xF8, 0x3F, 0x00, 0x01, 0x80, 0x03, 44 0xC0, 0x07, 0xF0, 0x1F, 0xF0, 0x1F, 0xE0, 0x0F, 0xE1, 0x0F, 0xE7, 0xCF, 0xDF, 0xF7, 0xFF, 0xFF 45 }; 46 47 byte topWords[][16][2] = //慶祝祖國70周年 48 { 49 {0x00}, 50 { 51 0x01, 0x00, 0x00, 0x80, 0x3F, 0xFE, 0x20, 0x00, 0x20, 0x80, 0x20, 0x80, 0x20, 0x80, 0x2F, 0xFC, 52 0x20, 0x80, 0x21, 0x40, 0x21, 0x40, 0x22, 0x20, 0x42, 0x20, 0x44, 0x10, 0x88, 0x08, 0x10, 0x06 53 }, 54 { 55 0x20, 0x00, 0x13, 0xFC, 0x12, 0x04, 0xFA, 0x04, 0x0A, 0x04, 0x12, 0x04, 0x13, 0xFC, 0x38, 0x90, 56 0x54, 0x90, 0x94, 0x90, 0x10, 0x90, 0x11, 0x12, 0x11, 0x12, 0x12, 0x12, 0x14, 0x0E, 0x18, 0x00 57 }, 58 { 59 0x20, 0x00, 0x11, 0xF8, 0x11, 0x08, 0xF9, 0x08, 0x09, 0x08, 0x11, 0xF8, 0x11, 0x08, 0x39, 0x08, 60 0x55, 0x08, 0x95, 0xF8, 0x11, 0x08, 0x11, 0x08, 0x11, 0x08, 0x11, 0x08, 0x17, 0xFE, 0x10, 0x00 61 }, 62 { 63 0x00, 0x00, 0x7F, 0xFC, 0x40, 0x04, 0x40, 0x04, 0x5F, 0xF4, 0x41, 0x04, 0x41, 0x04, 0x4F, 0xE4, 64 0x41, 0x04, 0x41, 0x44, 0x41, 0x24, 0x5F, 0xF4, 0x40, 0x04, 0x40, 0x04, 0x7F, 0xFC, 0x40, 0x04 65 }, 66 { 67 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x7C, 0x18, 0x44, 0x24, 0x44, 0x42, 0x08, 0x42, 0x08, 0x42, 68 0x10, 0x42, 0x10, 0x42, 0x10, 0x42, 0x10, 0x24, 0x10, 0x18, 0x00, 0x00, 0x00, 0x00 69 }, 70 { 71 0x00, 0x00, 0x3F, 0xF8, 0x21, 0x08, 0x21, 0x08, 0x2F, 0xE8, 0x21, 0x08, 0x21, 0x08, 0x3F, 0xF8, 72 0x20, 0x08, 0x27, 0xC8, 0x24, 0x48, 0x24, 0x48, 0x27, 0xC8, 0x40, 0x08, 0x40, 0x28, 0x80, 0x10 73 }, 74 { 75 0x10, 0x00, 0x10, 0x00, 0x1F, 0xFC, 0x20, 0x80, 0x20, 0x80, 0x40, 0x80, 0x1F, 0xF8, 0x10, 0x80, 76 0x10, 0x80, 0x10, 0x80, 0xFF, 0xFE, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80 77 }, 78 { 79 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, 80 0x00,0x00,0x00,0x00,0x00,0x00,0x30,0x00,0x30,0x00,0x10,0x00,0x20,0x00,0x00,0x00 81 } 82 83 }; 84 byte words[][16][2]= //願祖國繁榮昌盛，越來越好, 85 { 86 { 87 0x00,0x00,0x3F,0xFE,0x20,0x80,0x27,0xF8,0x24,0x08,0x27,0xF8,0x24,0x08,0x27,0xF8, 88 0x22,0x50,0x24,0x48,0x29,0x44,0x20,0x80,0x20,0x44,0x4A,0x42,0x4A,0x12,0x91,0xF0 89 }, 90 { 91 0x20,0x00,0x11,0xF8,0x11,0x08,0xF9,0x08,0x09,0x08,0x11,0xF8,0x11,0x08,0x39,0x08, 92 0x55,0x08,0x95,0xF8,0x11,0x08,0x11,0x08,0x11,0x08,0x11,0x08,0x17,0xFE,0x10,0x00 93 }, 94 { 95 0x00,0x00,0x7F,0xFC,0x40,0x04,0x40,0x04,0x5F,0xF4,0x41,0x04,0x41,0x04,0x4F,0xE4, 96 0x41,0x04,0x41,0x44,0x41,0x24,0x5F,0xF4,0x40,0x04,0x40,0x04,0x7F,0xFC,0x40,0x04 97 }, 98 { 99 0x20,0x20,0x3F,0x20,0x40,0x3E,0xBE,0x48,0x2A,0xA8,0xFF,0x28,0x4A,0x10,0x7F,0x28, 100 0x04,0x46,0x08,0x80,0x1F,0x00,0x02,0x10,0x3F,0xF8,0x01,0x08,0x15,0x20,0x22,0x10 101 }, 102 { 103 0x08,0x20,0x08,0x20,0xFF,0xFE,0x08,0x20,0x00,0x00,0x7F,0xFE,0x40,0x02,0x81,0x04, 104 0x01,0x00,0x7F,0xFC,0x03,0x80,0x05,0x40,0x09,0x20,0x31,0x18,0xC1,0x06,0x01,0x00 105 }, 106 { 107 0x1F,0xF0,0x10,0x10,0x10,0x10,0x1F,0xF0,0x10,0x10,0x10,0x10,0x1F,0xF0,0x00,0x00, 108 0x3F,0xF8,0x20,0x08,0x20,0x08,0x3F,0xF8,0x20,0x08,0x20,0x08,0x3F,0xF8,0x20,0x08 109 }, 110 { 111 0x00,0x90,0x00,0x88,0x3F,0xFC,0x20,0x80,0x20,0x88,0x3E,0x48,0x22,0x50,0x22,0x24, 112 0x4A,0x54,0x44,0x8C,0x81,0x04,0x3F,0xF8,0x24,0x48,0x24,0x48,0xFF,0xFE,0x00,0x00 113 }, 114 { 115 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, 116 0x00,0x00,0x00,0x00,0x00,0x00,0x30,0x00,0x30,0x00,0x10,0x00,0x20,0x00,0x00,0x00 117 }, 118 { 119 0x10,0x28,0x10,0x24,0x10,0x20,0x7D,0xFC,0x11,0x20,0x11,0x24,0xFD,0x24,0x11,0x28, 120 0x11,0x28,0x51,0x10,0x5D,0x94,0x51,0x2C,0x70,0x44,0x50,0x00,0x4F,0xFE,0x80,0x00 121 }, 122 { 123 0x01,0x00,0x01,0x00,0x01,0x00,0x7F,0xFC,0x01,0x00,0x11,0x10,0x09,0x10,0x09,0x20, 124 0xFF,0xFE,0x03,0x80,0x05,0x40,0x09,0x20,0x31,0x18,0xC1,0x06,0x01,0x00,0x01,0x00 125 }, 126 { 127 0x10,0x28,0x10,0x24,0x10,0x20,0x7D,0xFC,0x11,0x20,0x11,0x24,0xFD,0x24,0x11,0x28, 128 0x11,0x28,0x51,0x10,0x5D,0x94,0x51,0x2C,0x70,0x44,0x50,0x00,0x4F,0xFE,0x80,0x00 129 }, 130 { 131 0x10,0x00,0x10,0xFC,0x10,0x04,0x10,0x08,0xFC,0x10,0x24,0x20,0x24,0x20,0x25,0xFE, 132 0x24,0x20,0x48,0x20,0x28,0x20,0x10,0x20,0x28,0x20,0x44,0x20,0x84,0xA0,0x00,0x40 133 }, 134 { 135 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, 136 0x00,0x00,0x00,0x00,0x00,0x00,0x30,0x00,0x30,0x00,0x10,0x00,0x20,0x00,0x00,0x00 137 } 138 }; 139 byte leftWords[][16][2]= //我愛你中國！ 140 { 141 { 142 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, 143 0x00,0x00,0x1A,0x1C,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 144 }, 145 { 146 0x04,0x24,0x24,0x24,0x7F,0xC4,0x44,0x04,0x04,0xFF,0x04,0x44,0x34,0x05,0x04,0x00, 147 0x00,0x10,0x12,0x21,0xFE,0x40,0x82,0x02,0x04,0xC8,0x30,0x28,0x44,0x82,0x1F,0x00 148 }, 149 { 150 0x01,0x26,0x34,0x2C,0x24,0x24,0x37,0x4C,0x44,0x44,0x4C,0x74,0xC4,0x45,0x06,0x00, 151 0x00,0x82,0x84,0x89,0x91,0xE1,0xB2,0xAA,0xA4,0xA4,0xAA,0xB2,0x81,0x01,0x01,0x00 152 }, 153 { 154 0x00,0x01,0x06,0x1F,0xE0,0x02,0x04,0x18,0xF0,0x10,0x13,0x10,0x10,0x14,0x18,0x00, 155 0x80,0x00,0x00,0xFF,0x00,0x08,0x30,0xC0,0x02,0x01,0xFE,0x00,0x80,0x60,0x18,0x00 156 }, 157 { 158 0x00,0x00,0x0F,0x08,0x08,0x08,0x08,0xFF,0x08,0x08,0x08,0x08,0x0F,0x00,0x00,0x00, 159 0x00,0x00,0xF0,0x20,0x20,0x20,0x20,0xFF,0x20,0x20,0x20,0x20,0xF0,0x00,0x00,0x00 160 }, 161 { 162 0x00,0x7F,0x40,0x48,0x49,0x49,0x49,0x4F,0x49,0x49,0x49,0x48,0x40,0x7F,0x00,0x00, 163 0x00,0xFF,0x02,0x12,0x12,0x12,0x12,0xF2,0x12,0x52,0x32,0x12,0x02,0xFF,0x00,0x00 164 }, 165 { 166 0x00,0x00,0x00,0x7F,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, 167 0x00,0x00,0x00,0xCC,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 168 } 169 }; 170 171 172 void setup() { 173 for (int i = 0; i < 4; ++i) 174 { 175 led.shutdown(i, false);//關閉省電模式，這一步必須做，否則顯示不出來(因為在構造函數中，默認開啟了省電模式，所以，我們要關閉該模式)。 176 led.clearDisplay(i);//清空數據 177 } 178 maxLen = sizeof(words)/sizeof(*words);//計算總的字數 179 row = 16 * (sizeof(topWords) / sizeof(*topWords));//計算向上移動的字的總行數 180 col = 16 * (sizeof(leftWords) / sizeof(*leftWords));//計算向左移動的字的總列數 181 } 182 183 void loop() { 184 // put your main code here, to run repeatedly: 185 showWordByPtr(led, b); //顯示空心五角星 186 delay(500); 187 for(int i =0;i<5;++i) 188 { 189 showWordByArr(led, a); //實心五角星 190 delay(200); 191 showWordByArr(led, c); //空心取反 192 delay(200); 193 } 194 showWordByArr(led, a); //實心五角星 195 delay(800); 196 showTopMoveWords(led, topWords); //字向左滾動 197 delay(500); 198 showWords(led, words); //字原地變換 199 delay(100); 200 showLeftMoveWords(led, leftWords); //字向右滾動 201 delay(1000); 202 } 203 204 void showWordByArr(LedControl led, byte word[][2]) 205 { 206 for (int i = 0; i < 4; ++i) 207 { 208 if (i < 2) 209 { 210 for (int j = 0; j < 8; ++j) 211 { 212 led.setRow(i, j, word[j][i]); 213 } 214 } 215 else 216 { 217 for (int j = 0; j < 8; ++j) 218 { 219 led.setRow(i, j, word[j + 8][i - 2]); 220 } 221 } 222 } 223 } 224 225 void showWordByPtr(LedControl led, byte (*word)[2]) 226 { 227 for (int i = 0; i < 4; ++i) 228 { 229 if (i < 2) 230 { 231 for (int j = 0; j < 8; ++j) 232 { 233 led.setRow(i, j, *(*(word + j) + i)); 234 } 235 } 236 else 237 { 238 for (int j = 0; j < 8; ++j) 239 { 240 led.setRow(i, j, *(*(word + j + 8) + i - 2)); 241 } 242 } 243 } 244 } 245 246 void showWords(LedControl led, byte (*words)[16][2]) 247 { 248 for (int i = 0; i < maxLen; ++i) 249 { 250 showWordByPtr(led, *(words + i)); 251 delay(800); 252 } 253 } 254 255 void showTopMoveWords(LedControl led, byte(*words)[16][2]) 256 { 257 byte *temp = *(*words); //獲取第一個二維數組的第一行的(第一個元素)的指針 258 byte* dump = temp; 259 for(int n =0;n<=row-16;++n) 260 { 261 dump = temp; 262 for (int i = 0; i < 4; ++i)//共4塊8*8led點陣，每塊顯示完再到下一塊 263 { 264 dump = temp; 265 if (i < 2) //第一、二塊的點陣 266 { 267 for (int j = 0; j < 8; ++j) //每塊點陣共8行，所以循環8次 268 { 269 led.setRow(i, j, *(dump + i)); 270 dump+=2; //指向下一行的第一個位置 271 } 272 } 273 else //第三、四塊點陣顯示 274 { 275 dump+=16; //因為是顯示二維數組的后半部分，這里要加一下。 276 for (int j = 0; j < 8; ++j) 277 { 278 led.setRow(i, j, *(dump+i-2)); 279 dump+=2; 280 } 281 } 282 } 283 temp += 2;//每次循環完，指向下一行。 284 delay(35); //每次顯示之間間隔35ms,這是我自己測試的，如果想要更快或更慢可以相應調整這個參數。 285 } 286 } 287 288 void showLeftMoveWords(LedControl led, byte(*words)[16][2]) 289 { 290 byte* first = *(*words); 291 byte* firstChangeFlag = first + 15;//開始遍歷的指針需要變換的標志(也就是當first和firstChangeFlag相等時，說明first需要再偏移17). 292 byte* temp = first; //負責顯示第一、二個led點陣的指針 293 byte* temp1 = first + 16; //負責顯示第三、四個點陣的指針 294 for (int n = 0; n < col - 16; ++n) 295 { 296 temp = first; 297 temp1 = first + 16; 298 for (int i=0;i<4;++i) 299 { 300 if (i < 2) //第一、二個點陣 301 { 302 for (int j = 0; j < 8; ++j) 303 { 304 led.setColumn(i, j, *temp); 305 if (temp == firstChangeFlag) 306 { 307 temp += 17; 308 } 309 else 310 { 311 temp++; 312 } 313 } 314 } 315 else //第三、四個點陣 316 { 317 for (int k=0; k<8; ++k) 318 { 319 led.setColumn(i, k, *temp1); 320 if (temp1 == firstChangeFlag+16) 321 { 322 temp1 += 17; 323 } 324 else 325 { 326 temp1++; 327 } 328 } 329 } 330 } 331 if (first == firstChangeFlag) 332 { 333 first += 17; 334 firstChangeFlag = first + 15; 335 } 336 else 337 { 338 first++; 339 } 340 //delay(1000); 341 } 342 }
最后總結一下：
1. 漢字的點陣數組是使用16*16字模軟件提取出來的，我用的是字模提取 v2.2版本，網上搜一下就有。
2. 原來寫過的，只是單純的顯示漢字，這次把文字移動顯示加上去了。
3. 向左移動文字的那個函數想了好久才寫出來的，主要是太浮躁了，后來靜下心來仔細推敲，是發現指針遍歷數組的順序有問題，這才解決了。
4. 通過視頻可以看到，向左移動顯示的效果還是有點問題的，上面一半的顯示和下面一半的顯示有一點不同步，難道是處理器跟不上？(自我安慰)。希望有路過大神指點一下。
5. 最后要感謝下面的文章，是當初玩點陣入門的時候的參考資料。
Arduino Uno 使用MAX7219驅動單個8*8點陣LED模塊 - 凌順實驗室
2019-10-15更新：
今天上班鑽孔的時候(我是做模具的)，突然來了靈感，想到了解決橫向滾動，上下屏不同步的解決辦法。
回來一試，效果很好(幾乎看不出來，不同步了)。原來我是按照先顯示第1和第2塊led點陣，再顯示第3塊和第4塊點陣的方式的（這是向上滾動字幕的顯示方式），
既然向左滾動，那應該是先顯示最左邊的點陣，即先顯示第1和第3塊點陣，再顯示右邊的第2和第4塊led點陣，這樣就解決了，代碼稍加改動如下：
1 void showLeftMoveWords(LedControl led, byte(*words)[16][2]) 2 { 3 byte* first = *(*words); 4 byte* firstChangeFlag = first + 15;//開始遍歷的指針需要變換的標志(也就是當first和firstChangeFlag相等時，說明first需要再偏移17). 5 byte* temp = first; //負責顯示第一、二個led點陣的指針 6 byte* temp1 = first + 16; //負責顯示第三、四個點陣的指針 7 for (int n = 0; n < col - 16; ++n) 8 { 9 temp = first; 10 temp1 = first + 16; 11 //原來是先顯示第1塊和第2塊，再顯示第3,4塊的，所以導致上下屏不同步。 12 for (int i = 0; i < 2; ++i) //這里循環2次，分2次顯示，先顯示第1塊和第3塊led，再顯示第2塊和第4塊led。 13 { 14 for (int j = 0; j < 8; ++j) 15 { 16 led.setColumn(i, j, *temp); 17 if (temp == firstChangeFlag) 18 { 19 temp += 17; 20 } 21 else 22 { 23 temp++; 24 } 25 } 26 for (int k = 0; k < 8; ++k) 27 { 28 led.setColumn(i+2, k, *temp1); 29 if (temp1 == firstChangeFlag + 16) 30 { 31 temp1 += 17; 32 } 33 else 34 { 35 temp1++; 36 } 37 } 38 } 39 if (first == firstChangeFlag) 40 { 41 first += 17; 42 firstChangeFlag = first + 15; 43 } 44 else 45 { 46 first++; 47 } 48 } 49 }
再次總結：
1. 這個點陣模塊在某寶上花了三十幾塊大洋買的，玩到這樣也算對的起我的大洋了。。。
2. 突然發現，點陣可以拿來玩一些數據結構的演練，有空得好好試下玩玩(比如，拿這點陣玩貪吃蛇。。。)。
3. 遇到問題，一定要冷靜思考，切勿焦躁，煩躁是大忌，這也是成為一名職業程序員的基本修養(雖然，目前還不是)。