如何从 setup() 中的 Serial 读取字符数组并等待足够长的时间让用户点击发送？

Question

I am using an Arduino Mega, and it will be bluetooth controlled with a Bluetooth Terminal app for Arduino. What I want it to do is, when it starts up, at setup- I want it to prompt the user for a 4 digit PIN, and once the user is finished entering the pin and hits send the program should proceed further and not before that. This is what I tried

unsigned char buff[4];

void getPassword() {

  int j = 0;

  Serial1.println("Enter the PIN: ");

  for (;;) {
    while (Serial1.available() > 0) {
      buff[j] = Serial1.read();
      j++;
    }

    if (j >= 3) {

      break;
    }
  }
}

void setup() {

getPassword();
}

It doesn't seem to work at all. How do I achieve this?

Answer 1

I notice that your password buffer is 4 chars long. But you are only reading 3 characters from Serial. IS the password actually 3 or 4 characters long? If it is 4 characters long, then when j is 3 it isn't time to exit that loop yet. When j is 3 you are waiting for the fourth character. You want to exit AFTER you read the fourth character and j gets incremented again and becomes 4.