snipplets.dev/code/Arduino/variables_sizes.ino

/**
 * Скетч, который выводит в Serial размер типов переменных в байтах
 */

void setup() {
  Serial.begin(9600);

  size_t size_variable;

  int example_int;
  unsigned int example_uint;
  signed int example_sint;
  unsigned long example_ulint;
  float example_float;
  double example_double;
  char example_char;
  char * example_string;
  bool example_bool;

  size_variable = sizeof(example_int);
  Serial.print("int bytes size:            " );
  Serial.println(size_variable);

  size_variable = sizeof(example_uint);
  Serial.print("unsigned int bytes size:   " );
  Serial.println(size_variable);

  size_variable = sizeof(example_sint);
  Serial.print("signed int bytes size:     " );
  Serial.println(size_variable);

  size_variable = sizeof(example_ulint);
  Serial.print("unsigned long bytes size:  " );
  Serial.println(size_variable);

  size_variable = sizeof(example_float);
  Serial.print("float bytes size:          " );
  Serial.println(size_variable);

  size_variable = sizeof(example_double);
  Serial.print("double bytes size:         " );
  Serial.println(size_variable);

  size_variable = sizeof(example_char);
  Serial.print("char bytes size:           " );
  Serial.println(size_variable);

  size_variable = sizeof(example_string);
  Serial.print("char * bytes size:         " );
  Serial.println(size_variable);

  size_variable = sizeof(example_bool);
  Serial.print("bool bytes size:           " );
  Serial.println(size_variable);
}

void loop() {
  //
}

/**
 * Arduino Nano
 *
 * int bytes size:            2
 * unsigned int bytes size:   2
 * signed int bytes size:     2
 * unsigned long bytes size:  4
 * float bytes size:          4
 * double bytes size:         4
 * char bytes size:           1
 * char * bytes size:         2
 * bool bytes size:           1
 */