// ligar led com rele e botoes:
 
int botaoon = 2;
int botaoof = 3;
int led = 12;

void setup
{
  pinMode (botaoon, INPUT_PULLUP)
  pinMode (botaooff, INPUT_PULLUP)
  pinMode (led, OUTPUT)
}
  
void loop
{
  if (digitalRead(botaoon) == LOW)
      digitalWrite (led, HIGH);
else if (digitalRead (botaoof) == LOW)
digitalWrite(led, LOW);
}