const byte dataLen = 4;
  const byte weightsLen = dataLen * 2;
  uint16_t weight;
  char weights[weightsLen];
  byte idx;

//ab cd ef ...
uint16_t arr[6] = {0x6162, 0x6364, 0x6566, 0x6768, 0x6970, 0x7172};


void setup() {
  Serial.begin(115200);
  delay(500);
  Serial.println();  
  for (uint16_t j = 0; j < dataLen; j++) {
    weight = arr[random (6)]; // 0x6364; 
    uint16_t k=j*2;
    weights[k]  =highByte(weight);
    weights[k+1]=lowByte(weight);
    Serial.print(weight);
    Serial.print(",");
    Serial.print(weights[k]);      
    Serial.print(weights[k+1]);
    Serial.print("\t");  
  }
  Serial.println();
  Serial.println(weights); 
  Serial.println(String("Size: ") + sizeof(weights)); 
  for (uint16_t j = 0; j < dataLen; j++) {
    uint16_t k=j*2;
    Serial.print((weights[k]<<8)|weights[k+1]);
    //(byte2<<16) | (byte1<<8) | (byte0) - это если 3 байта
    Serial.print(",");
    Serial.print(weights[k]);      
    Serial.print(weights[k+1]);
    Serial.print("\t"); 
  }
  Serial.println();
}

void loop() {  
  delay(10); // this speeds up the simulation
}