c++ - Adafruit NeoPixel 库在处理超过 7 个 LED 灯条时不起作用

Question

关于我关于 SO 的最后一个问题，我正在研究一个由 Arduino Mega 控制的交互式 14x14 LED table (有关设置和代码的更多信息，请查看 here。在解决了数据以错误的顺序到达 Arduino 的问题后，我现在面临这个问题:

为了使用 Adafruit 的 NeoPixel 库控制 LED 台上每个像素的颜色，我读取了一个 int[14][14][3] 形式的数组。这现在工作正常，但是当我尝试为超过 7 个 LED 灯带设置 RGB 值时，没有任何反应。我还有几个 Serial.println() 调用来检查读取了哪些数据，如果我运行的 LED 灯条超过 7 个，则为每个可能的值打印 0。

控制 LED 的基本功能完美运行 - 只要我使用的灯带不超过 7 个，我也可以正确处理上述数据并将其输出到 LED 灯带。问题是，如果我在一个数组中声明多于这 7 个 strip 或拆分它们都没有关系。此外，每次我想使用不同的 strip 时，单独初始化它们也无法创建一个 strip 实例并为其重新分配引脚。

我的代码目前看起来像这样，我完全不知道这个问题可能是什么原因或我该如何解决。

#include <ArduinoJson.h>
#include <Adafruit_NeoPixel.h>

#ifdef __AVR__
#include <avr/power.h> // Required for 16 MHz Adafruit Trinket
#endif

#define PINROW0 0
#define PINROW1 1
#define PINROW2 2
#define PINROW3 3
#define PINROW4 4
#define PINROW5 5
#define PINROW6 6
#define PINROW7 7
#define PINROW8 8
#define PINROW9 26
#define PINROW10 28
#define PINROW11 30
#define PINROW12 32
#define PINROW13 34

#define NUMPIXELS 14 //Anzahl der Pixel pro Reihe

/*Adafruit_NeoPixel row0 = Adafruit_NeoPixel(NUMPIXELS, PINROW0, NEO_GRB + NEO_KHZ800);
  Adafruit_NeoPixel row1 = Adafruit_NeoPixel(NUMPIXELS, PINROW1, NEO_GRB + NEO_KHZ800);
  Adafruit_NeoPixel row2 = Adafruit_NeoPixel(NUMPIXELS, PINROW2, NEO_GRB + NEO_KHZ800);
  Adafruit_NeoPixel row3 = Adafruit_NeoPixel(NUMPIXELS, PINROW3, NEO_GRB + NEO_KHZ800);
  Adafruit_NeoPixel row4 = Adafruit_NeoPixel(NUMPIXELS, PINROW4, NEO_GRB + NEO_KHZ800);
  Adafruit_NeoPixel row5 = Adafruit_NeoPixel(NUMPIXELS, PINROW5, NEO_GRB + NEO_KHZ800);
  Adafruit_NeoPixel row6 = Adafruit_NeoPixel(NUMPIXELS, PINROW6, NEO_GRB + NEO_KHZ800);
  Adafruit_NeoPixel row7 = Adafruit_NeoPixel(NUMPIXELS, PINROW7, NEO_GRB + NEO_KHZ800);
  Adafruit_NeoPixel row8 = Adafruit_NeoPixel(NUMPIXELS, PINROW8, NEO_GRB + NEO_KHZ800);
  Adafruit_NeoPixel row9 = Adafruit_NeoPixel(NUMPIXELS, PINROW9, NEO_GRB + NEO_KHZ800);
  Adafruit_NeoPixel row10 = Adafruit_NeoPixel(NUMPIXELS, PINROW10, NEO_GRB + NEO_KHZ800);
  Adafruit_NeoPixel row11 = Adafruit_NeoPixel(NUMPIXELS, PINROW11, NEO_GRB + NEO_KHZ800);
  Adafruit_NeoPixel row12 = Adafruit_NeoPixel(NUMPIXELS, PINROW12, NEO_GRB + NEO_KHZ800);
  Adafruit_NeoPixel row13 = Adafruit_NeoPixel(NUMPIXELS, PINROW13, NEO_GRB + NEO_KHZ800);
*/

//Adafruit_NeoPixel currentStrip = Adafruit_NeoPixel(NUMPIXELS, pins[0], NEO_GRB + NEO_KHZ800);
Adafruit_NeoPixel row[] = { //Initialisieren des Arrays, das die addressierbaren LED Streifen im Adafruit Format enthält
  Adafruit_NeoPixel(NUMPIXELS, PINROW0, NEO_GRB + NEO_KHZ800),
  Adafruit_NeoPixel(NUMPIXELS, PINROW1, NEO_GRB + NEO_KHZ800),
  Adafruit_NeoPixel(NUMPIXELS, PINROW2, NEO_GRB + NEO_KHZ800),
  Adafruit_NeoPixel(NUMPIXELS, PINROW3, NEO_GRB + NEO_KHZ800),
  Adafruit_NeoPixel(NUMPIXELS, PINROW4, NEO_GRB + NEO_KHZ800),
  Adafruit_NeoPixel(NUMPIXELS, PINROW5, NEO_GRB + NEO_KHZ800),
  Adafruit_NeoPixel(NUMPIXELS, PINROW6, NEO_GRB + NEO_KHZ800),
  Adafruit_NeoPixel(NUMPIXELS, PINROW7, NEO_GRB + NEO_KHZ800),
  Adafruit_NeoPixel(NUMPIXELS, PINROW8, NEO_GRB + NEO_KHZ800)/*,
  Adafruit_NeoPixel(NUMPIXELS, PINROW9, NEO_GRB + NEO_KHZ800),
  Adafruit_NeoPixel(NUMPIXELS, PINROW10, NEO_GRB + NEO_KHZ800),
  Adafruit_NeoPixel(NUMPIXELS, PINROW11, NEO_GRB + NEO_KHZ800),
  Adafruit_NeoPixel(NUMPIXELS, PINROW12, NEO_GRB + NEO_KHZ800),
  Adafruit_NeoPixel(NUMPIXELS, PINROW13, NEO_GRB + NEO_KHZ800)*/
};


#define DELAY 1000 //Refresh Zyklus auf 10 Millisekunden setzen
#define NUMSTRIPS 9/*(sizeof(row)/sizeof(row[0]))*/ //Anzahl der verbundenen LED Streifen definieren


int values[14][14][3];
String matrixAsString = "";

void setup() {

#if defined(__AVR_ATtiny85__) && (F_CPU == 16000000)
  clock_prescale_set(clock_div_1);
#endif

  /*Seriellen Port über den der Pi sich mit dem Arduino verbindet einrichten*/
  Serial.begin(115200); //setzen der Bitrate auf 115200 Bit pro Sekunde
  Serial.setTimeout(100000);

  /*NeoPixel Library initialisieren*/
  for (int i = 0; i < NUMSTRIPS; i++) {
    row[i].begin();
    row[i].show();
  }
}

void process(String matrixAsString) {
  DynamicJsonDocument doc(4372);
  Serial.println(matrixAsString);
  deserializeJson(doc, matrixAsString);

  Serial.println((int)(doc[2][10][0]));
  Serial.println((int)(doc[2][10][0]));
  Serial.println((int)(doc[5][10][0]));
  Serial.println((int)(doc[0][1][2]));
  Serial.println((int)(doc[0][0][1]));

  for (int i = 0; i < NUMSTRIPS; i++) {
    for (int j = 0; j < NUMPIXELS; j++) {
      for (int k = 0; k < 3; k++) {
        values[i][j][k] = (int)(doc[i][j][k]);
      }
    }
  }
}

void paint() {
  int r = 0;
  int g = 0;
  int b = 0;
  for (int i = 0; i < NUMSTRIPS; i++) {
    for (int j = 0; j < NUMPIXELS; j++) {
      r = values[i][j][0];
      g = values[i][j][1];
      b = values[i][j][2];
      row[i].setPixelColor(j, row[i].Color(r, g, b));
      row[i].show();
    }
  }
}

//infinite loop refreshing the matrix
void loop() {

  while (Serial.available()) {
    char c = Serial.read();
    matrixAsString += c;
    if (c == '\n') {
      process(matrixAsString);
      paint();
      matrixAsString = "";
    }

  }

}

根据官方 Adafruit 文档，库设计为连接 Arduino 能够支持的 strip 数量，因此必须有一个解决方案。

为了测试我的代码，我使用了这个数据，它是随机生成的 14x14 RGB 矩阵的字符串表示形式:

[[[0,0,0],[1,0,0],[1,1,0],[2,1,0],[2,2,0],[3,2,0],[3,3,0],[3,3,1],[3,3,2],[3,3,3],[4,3,3],[4,4,3],[5,4,3],[5,4,4]],[[6,4,4],[7,4,4],[7,5,4],[7,6,4],[7,7,4],[7,7,5],[7,7,6],[7,7,7],[7,7,8],[8,7,8],[8,8,8],[8,9,8],[8,10,8],[8,11,8]],[[8,11,9],[8,11,10],[9,11,10],[9,11,11],[9,12,11],[9,12,12],[9,13,12],[10,13,12],[10,13,13],[10,13,14],[10,13,15],[11,13,15],[11,14,15],[11,15,15]],[[12,15,15],[12,15,16],[12,15,17],[13,15,17],[13,16,17],[13,16,18],[14,16,18],[14,17,18],[15,17,18],[15,17,19],[15,18,19],[15,18,20],[15,19,20],[15,19,21]],[[15,20,21],[15,21,21],[16,21,21],[17,21,21],[17,22,21],[18,22,21],[19,22,21],[19,23,21],[20,23,21],[20,23,22],[20,23,23],[20,24,23],[20,25,23],[20,26,23]],[[21,26,23],[22,26,23],[22,27,23],[23,27,23],[23,27,24],[24,27,24],[24,27,25],[24,28,25],[24,28,26],[24,29,26],[24,29,27],[24,29,28],[24,30,28],[25,30,28]],[[25,30,29],[25,31,29],[25,31,30],[26,31,30],[27,31,30],[27,32,30],[27,32,31],[27,33,31],[27,34,31],[27,35,31],[27,35,32],[28,35,32],[28,36,32],[29,36,32]],[[29,37,32],[29,37,33],[29,38,33],[29,38,34],[30,38,34],[31,38,34],[32,38,34],[33,38,34],[33,39,34],[33,39,35],[33,39,36],[33,40,36],[33,40,37],[33,41,37]],[[33,42,37],[33,42,38],[33,42,39],[33,42,40],[33,43,40],[33,43,41],[33,43,42],[33,44,42],[33,45,42],[33,45,43],[33,46,43],[34,46,43],[34,47,43],[35,47,43]],[[36,47,43],[37,47,43],[38,47,43],[38,47,44],[39,47,44],[39,47,45],[39,48,45],[40,48,45],[40,48,46],[40,49,46],[41,49,46],[41,50,46],[41,51,46],[41,51,47]],[[42,51,47],[42,51,48],[43,51,48],[43,51,49],[43,52,49],[43,53,49],[43,54,49],[43,54,50],[44,54,50],[44,55,50],[45,55,50],[45,55,51],[46,55,51],[47,55,51]],[[48,55,51],[48,56,51],[48,57,51],[48,58,51],[48,58,52],[48,58,53],[48,59,53],[48,59,54],[48,60,54],[48,60,55],[48,60,56],[48,60,57],[49,60,57],[49,61,57]],[[49,62,57],[49,62,58],[49,63,58],[49,63,59],[50,63,59],[50,64,59],[50,65,59],[51,65,59],[52,65,59],[53,65,59],[54,65,59],[54,66,59],[54,66,60],[54,67,60]],[[55,67,60],[56,67,60],[57,67,60],[58,67,60],[59,67,60],[59,67,61],[59,68,61],[59,69,61],[60,69,61],[61,69,61],[61,69,62],[61,69,63],[61,70,63],[61,71,63]]]

预先感谢您的帮助，我非常感谢您提供的任何提示或建议。

Answer 1

你只有 8kB 的 ram 而你正在使用:

• int values[14][14][3]; => 这个数组有 1176 个字节(而不是一半，如果你使用 byte/uint8_t 而不是 int)
• Freaking String matrixAsString = ""; 和 += 运算符。这会严重扰乱内存(就内存碎片而言)。
• DynamicJsonDocument doc(4372); 分配另一个巨大的内存
• 更不用说，每个 strip 都有自己的像素内存，所以 values 数组有点无关紧要
• 也许可以使用相同的缓冲区来读取和 json 解析器？这可能会节省很多

所以根据那个，你一定是内存不足

无论如何，我会使用一些体面的 ARM 和 DMA 魔法(例如在 STM32 MCU 上同时使用 16 个 channel )而无需 CPU 的太多交互来发送它。或现有解决方案，如 OctoWS2811 LED Library