Sending bytes with write

Projects Programming
1

I got an intresting probleam.
The code below works fine. When a pin pulls high the corect byte is sent. However these are not the bytes i want to be sending. When i change the command array to look like this byte commands[] = {0x00, 0x01}; the arduino goes nuts. Pin 13 starts blinking and the serial port stas dumping out 0x0d or 0xd0 i cant rember. if i pull the pins high I will see 0x00 or 0x01 but the garbage is undesirable. In the end i hope to have around 10 inputs and sending a serial command for each one. Any ideas?

  int inputPins[] = {2,3};
  byte commands[] = {0x41, 0x42};
  int totalPins;
  int ledPin = 13;
  int delayTime = 250;


void setup(){
  totalPins = sizeof(inputPins);
  
  for(int n = 0; n < totalPins; n++){
    pinMode(inputPins[n], INPUT);
  }
  
  pinMode(ledPin, OUTPUT);
  Serial.begin(9600);
}

void loop(){
  for(int n = 0; n < totalPins; n ++){
    if(digitalRead(inputPins[n]) == HIGH){
      blink();
      Serial.write(commands[n]);
      delay(delayTime);
    }
    delay(10);
  }
}


void blink(){
  digitalWrite(ledPin, HIGH);
  delay(100);
  digitalWrite(ledPin, LOW);
}
2

You've used 'sizeof()' to initialise 'totalPins'. This will return the number of bytes in the array, not the number of elements. So you'll get 4 instead of 2, given that an 'int' is two bytes. If in doubt, print 'totalPins' with Serial.println. To get the number of elements in an array, you could say:

totalPins = sizeof(inputPins) / sizeof (inputPins[0]);
3

Wow i get that thanks.