(SKU:SEN0177)PM2.5激光粉尘传感器的Demo代码注释错误

int length = serialRead(Serial,receiveDat,receiveDatIndex,5);
上面这句，最后那个",5"是什么意思？

已修改，谢谢提醒

#include "Arduino.h"
#include "serialReadPMValue.h"
uint16_t PM2_5Value=0; //define PM2.5 value of the air detector module
#define receiveDatIndex 32
uint8_t receiveDat[receiveDatIndex]; //receive data from the air detector module
#include
LiquidCrystal lcd(8, 9, 4, 5, 6, 7);
void setup() {
Serial.begin(9600); //set the serial's Baudrate of the air detector module
lcd.begin(16, 2);
}
void loop(){
lcd.setCursor(0, 0); // set the LCD cursor position
int length = serialRead(Serial,receiveDat,receiveDatIndex,5); //change the serial port:Serial1,Serial2..
int checkSum=checkValue(receiveDat,receiveDatIndex);
if(length&&checkSum) {
PM2_5Value=transmitPM2_5(receiveDat);//count PM2.5 value of the air detector module
}
static unsigned long OledTimer=millis(); //every 0.5s update the temperature and humidity from DHT11 sensor
if (millis() - OledTimer >=1000)
{
OledTimer=millis();
lcd.print("pm2.5: ");
lcd.print(PM2_5Value);
lcd.print(" ug/m3");
Serial.print("PM2.5: "); //send PM1.0 data to bluetooth
Serial.print(PM2_5Value);
Serial.println(" ug/m3");
}
}

不对那就看我的吧。