C++ LiquidCrystal::println方法代码示例

void setup()
{
    RFID.begin(9600); // start serial to RFID reader
    Serial.begin(9600); // start serial to PC
    lcd.begin(16, 2);
    //lcd output
        lcd.clear();
        lcd.print("There are "); //start printing the result
        lcd.print(space_left); //then how many spaces
        lcd.print("  spaces left."); //words
        lcd.println(" "); //spaces
    
    for (int i = 0; i < 5; i++)
    {
       id_marker[i] = 0;
    }
    
    Serial.println("Ready!");
     
  //sets everything in the array equal to blank
 for(int i=0; i<5; i++)
        {
            id_array[i] = String("");
        }
  
}

void loop()
{
    int i;
    while (RFID.available() <= 0); // force wait until rfid present
    
    if(RFID.available() > 0) //does rfid exist?
    {
        i = 0;
        
        while (i < 14)
        {
        
            tag_id = RFID.read(); //Reads character, puts into tag_id
            
            
            if (tag_id == '-1')  //Wait for scan to read
                continue;
            
            id_string = String(id_string + tag_id); //Make it a string
            
            //TESTING OUTPUT
            
            //For some reason, getting rid of this makes the tag not read correctly 
            Serial.print("Read:  "); 
            Serial.print(tag_id);
            Serial.print("\nid_string is now "); 
            Serial.print(id_string); 
            
            i++; //counts up unil 14
        }
            
        //TESTING OUTPUT
        Serial.print("\nid_string is now ");
        Serial.print(id_string);
        
        
        for(int index=0; index<5; index++)  //first we check to see if there are any current matches
        {
        
            if(id_string == id_array[index]) //if the id matches something in the array at location "i"
            {
                Serial.println("Match"); //print that it matches.
                id_array[index] = String("");    //set the array location of the removed tag to blank
                
                if (id_marker[index] == 1)  //if the id marker is equal to one
                //else //Removing this else because I dont think it makes sense. 
                {
                    // space_left++; //this isnt properly increasing the spaces left
                    //Commented out space left above because theres also one below.
                    
                    
                    // not sure if this is necessary 
                    for (int j = index; j < 4; j++)   //what purpose does j serve? Increments the search?
                    {
                        id_string[j] = id_string[j + 1]; 
                        id_marker[j] = id_marker[j + 1];
                        Serial.println(id_marker[index]);  //test print for the current marker. 
                    }
                    
                    index--;  //this might actually only subtract the last place, and not the proper location
                    space_left++;
                    no_match = 1;
                }
            
            }
        
        }//End of for loop
            
        //I added the ifs below to attempt to refine the location of the write location in the array. they dont work completely
        if (no_match == 0)
        {
            if (id_array[index] != String(""))   //if the array location is not blank, then
            {
                index ++;   //increment to the next spot
                Serial.println(i);
            }
            
            if (index == 5)  //if we're at the 5th spot
            {
                index = 0; //start back at zero
            }
            //this needs to be able to detect black values
            id_array[index] = id_string;
            id_marker[index]++;
            space_left--;  
        }
    
    }
        
    Serial.println(" "); // prints a space
    Serial.println(id_array[index]); // print the array item
    Serial.println("Finished Reading ID."); //prints out this on a line
    Serial.print("There are "); //start printing the result
    Serial.print(space_left); //then how many spaces
    Serial.print(" spaces left."); //words
    Serial.println(" "); //spaces
    
    //lcd output
    lcd.clear();
    lcd.print("There are "); //start printing the result
//.........这里部分代码省略.........