I am trying to create a basic snake game using the arduino UNO along with the MAX72XX module, the LCD module and the analog joystick module. I am wanting to program my program using object orientated programming. I have no experience with C++ so I am struggling quite a bit to understand why the serial comes up with unusual characters whenever I am trying to print off variable values. The serial is able to print text, but whenever I try to print variable values the unusual characters come up. I had tried changing the baud to a higher one and that makes no difference. The two variables that I am trying to print off both have an integer data type. I have tried using Serial.write, Serial.print and Serial.println, none of these seem to work. Here is the code if it helps solve the problem:
#include "LedControl.h"
#include <LiquidCrystal.h>
LedControl lc=LedControl(12,10,11,1);
LiquidCrystal lcd(8, 13, 3, 5, 6, 7);
class Snake_body
{
public:
int following_direction;
int x;
int y;
int previous_x;
int previous_y;
bool enabled;
Snake_body()
{
this->enabled = false;
}
void configure(int x_value, int y_value)
{
this->enabled = true;
this->following_direction = 1;
this->x = x_value;
this->y = y_value;
this->previous_y = y_value;
this->previous_x = x_value;
}
};
class Power_up
{
private:
public:
virtual void init()
{
this->x = 0;
this->y = 0;
}
int x;
int y;
};
Snake_body *snake[64];//this is the snake array that contains the snake objects
int snakes_length;
Power_up *power_up;//define the power up object
int score;
void setup() {
Serial.begin(9600);
lcd.begin(16, 2);
snakes_length = 1;
for(int z = 1; z < 64; z++)
{
snake[z] = new Snake_body();//create 63 un-enabled snake objects
}
snake[0] = new Snake_body();//the 1st snake object is defined
snake[0]->configure(0,0);//here it is initialised
power_up = new Power_up();//create the power_up object
lc.shutdown(0,false);
lc.setIntensity(0,8);
lc.clearDisplay(0);
lcd.setCursor(0, 0);
score = 0;
lcd.print("score: ");
lcd.setCursor(6, 0);
lcd.print(score);
pinMode(2, INPUT);
digitalWrite(2, HIGH);
power_up->x = random(0, 8);
power_up->y = random(0, 8);
}
int snake_direction;
void loop()
{
int x_axis = analogRead(A0);
int y_axis = analogRead(A1);
int switcher = digitalRead(2);
if(x_axis <= 400) //&& x < 7)//each of the if statements are for the direction of the snake head (snake[0])
{
snake[0]->following_direction = 0;
//x += 1;
//Serial->println("right");
}
else if(x_axis >= 600) //&& x > 0)
{
snake[0]->following_direction = 1;
//x -= 1;
//Serial->println("left");
}
else if(y_axis <= 400) //&& y > 0)
{
snake[0]->following_direction = 2;
//y -= 1;
//Serial->println("up");
}
else if(y_axis >= 600) //&& y < 7)
{
snake[0]->following_direction = 3;
//y += 1;
//Serial->println("down");
}
if(snake[0]->following_direction == 0 && snake[0]->x < 7)//used for snake movement
{
snake[0]->previous_x = snake[0]->x;
snake[0]->x += 1;
}
else if(snake[0]->following_direction == 1 && snake[0]->x > 0)//used for snake movement
{
snake[0]->previous_x = snake[0]->x;
snake[0]->x -= 1;
}
else if(snake[0]->following_direction == 2 && snake[0]->y > 0)//used for snake movement
{
snake[0]->previous_y = snake[0]->y;
snake[0]->y -= 1;
}
else if(snake[0]->following_direction == 3 && snake[0]->y < 7)//used for snake movement
{
snake[0]->previous_y = snake[0]->y;
snake[0]->y += 1;
}
if(snake[0]->x == power_up->x && snake[0]->y == power_up->y)//used for collision with power up
{
score += 1;
lcd.setCursor(6,0);
lcd.print(score);
power_up->x = random(0, 8);
power_up->y = random(0, 8);
for(int j = 0; j < 64; j++)
{
if(snake[j]->enabled == false)//enables the next un-enabled snake object in the array
{
//Serial.println(true);
Snake_body *snake[j];
//next_snake_body = new Snake_body();
//Snake_body next_snake_body;
snake[j] = new Snake_body();
snake[j]->configure(snake[j-1]->previous_x, snake[j-1]->previous_y);
//Serial.print("x: " + snake[j-1]->previous_x);
//Serial.print("y: " + snake[j-1]->previous_y);
snake[j]->following_direction = NULL;
break;
}
}
}
for(int i = 1; i < 64; i++)
{
if(snake[i]->enabled == true)//updates each snake object in the array
{
snake[i]->x = snake[i-1]->previous_x;
snake[i]->y = snake[i-1]->previous_y;
}
}
lc.setLed(0,power_up->x,power_up->y,true);//draws the power up
for(int w = 0; w < 64; w++)
{
if(snake[w]->enabled == true)//draws each snake object that is enabled
{
Serial.print("x: " + snake[w]->x);
Serial.print("y: " + snake[w]->y);
lc.setLed(0,snake[w]->x,snake[w]->y,true);
}
}
/*Serial->print("x: ");
Serial->print(snake->x);
Serial->println();
Serial->print("y: ");
Serial->print(snake->y);
Serial->println();*/
delay(100);
lc.clearDisplay(0);
}
the weird characters that show up are characters like this:
with the follow picture y is just simply text to show which axis it is, the weird characters are the integer y axis value of the snake object that is being looked at.
Snake_body *snake[j];.. this does nothing and looks like a variable declaration, I'd remove that. Also in the beginning yousnake[z] = new Snake_body();but don't initialize the values (likey,x) in them via a constructor orinitialize()function -- those will be random then and possibly garbage. You calso callSerial->print(snake->x);butsnakeis an 64-element array ofSnakepointers, so that won't work. You need an index here.snake[j] = new Snake_body();. There already is aSnake_bodyelement in there and you've overwritten the pointer to it with a newly allocated object withoutdelete-ing the previous on -- reevaluate whether you really need to allocate a new object here of want to modify the existing one. If the latter, cleanup the memory.