Ooops - I spoke too soon.
If I put these in the loop, once I write the value high, it can not be set low again...
I got tired of measuring it with the meter so I tied a LED & 370 ohm resistor from D0 to ground to monitor it
The LED stays on once a HIGH is written to D0 and does not go off indicating that DO has not been set to a Low state
even though the code performs digitalWrite(D0,LOW)...
What is going on?
Here is my simplified code that produces these results:
void setup ()
{
Serial.begin (115200);
pinMode (0, OUTPUT);
digitalWrite (0, LOW);
}
void loop () {
digitalWrite (0, HIGH);
delay(3000); // delay 3 secs
digitalWrite (0, LOW);
delay(3000); // delay 3 secs
}