int relay1 = 2;
int relay2 = 3;
int relay3 = 4;
int relay4 = 5;
int relay5 = 6;
int relay6 = 7;
int relay7 = 8;
int relay8 = 9;

void setup()
{
  pinMode(relay1, OUTPUT);
  pinMode(relay2, OUTPUT);
  pinMode(relay3, OUTPUT);
  pinMode(relay4, OUTPUT);
  pinMode(relay5, OUTPUT);
  pinMode(relay6, OUTPUT);
  pinMode(relay7, OUTPUT);
  pinMode(relay8, OUTPUT);
  digitalWrite(relay1, LOW);
  digitalWrite(relay2, LOW);
  digitalWrite(relay3, LOW);
  digitalWrite(relay4, LOW);
  digitalWrite(relay5, LOW);
  digitalWrite(relay6, LOW);
  digitalWrite(relay7, LOW);
  digitalWrite(relay8, LOW);
  Serial.begin(9600);
}

void loop()
{
  char c = Serial.read();
  if (c == 'a') digitalWrite(2,HIGH);
  if (c == 'A') digitalWrite(2,LOW);
  if (c == 'b') digitalWrite(3,HIGH);
  if (c == 'B') digitalWrite(3,LOW);
  if (c == 'c') digitalWrite(4,HIGH);
  if (c == 'C') digitalWrite(4,LOW);
  if (c == 'd') digitalWrite(5,HIGH);
  if (c == 'D') digitalWrite(5,LOW);
  if (c == 'e') digitalWrite(6,HIGH);
  if (c == 'E') digitalWrite(6,LOW);
  if (c == 'f') digitalWrite(7,HIGH);
  if (c == 'F') digitalWrite(7,LOW);
  if (c == 'g') digitalWrite(8,HIGH);
  if (c == 'G') digitalWrite(8,LOW);
  if (c == 'h') digitalWrite(9,HIGH);
  if (c == 'H') digitalWrite(9,LOW);
}