Using digitalRead on an output

Projects Programming
1

I am using a digital pin as an output. After writing, I would like to perform a digitalRead to confirm the write.
However, the digitalRead responds with an "Off" (0) no matter the actual state of the pin.
Is this not possible? Is there a better way of making this confirmation, or is there a good argument that this extra check is overkill?

Thanks...

2

It's overkill!.

Mark

3

Why you want to confirm?

4

Is this not possible?

Yes.

Is there a better way of making this confirmation

You know the value you just wrote to the pin. Remember it.

However, the digitalRead responds with an "Off" (0) no matter the actual state of the pin.

No, it doesn't. It returns HIGH or LOW, not "off".

If you are seeing different results with your code, keep in mind that you are the only one that see it.

5

how about this little "Blink without an LED" routine.

void setup()
{
  Serial.begin(115200);
  pinMode(13, OUTPUT);
}

void loop()
{
  digitalWrite(13, !digitalRead(13));
  Serial.println(digitalRead(13) == HIGH ? "High" : "Low");
  delay(1000);
}