#define DECIMALS_MAX_BCD			3
#define UNITS_MAX_BCD				  2

//void (*letters[DECIMALS_MAX_BCD+1][UNITS_MAX_BCD+1])() = {
void (*letters[][UNITS_MAX_BCD+1])() = {
  { []()->void { Serial.println("[0][0]");},
		[]()->void { Serial.println("[0][1]");} },

	{ []()->void { Serial.println("[1][0]");},
		/*[]()->void { Serial.println("[1][1]");}*/ },

	{ []()->void { Serial.println("[2][0]");},
		[]()->void { Serial.println("[2][1]");} },
 
	{ []()->void { Serial.println("[3][0]");},
		[]()->void { Serial.println("[3][1]");} }
};


void setup() {
  Serial.begin(115200);
  Serial.println("Hello, STM32!");
}

void loop() {
  if (Serial.available()) {
    int vch = Serial.parseInt();
		int decs = vch/10;
		int units = vch%10;
    if (((decs <= DECIMALS_MAX_BCD) && ( units <= UNITS_MAX_BCD)) && (letters[decs][units])) 
		{
      letters[decs][units]();
    }
		Serial.flush();
  }
  delay(10);
}