Single shot

Using Arduino Project Guidance
4

Ok so could you apply your thery to this

int sensorPin = A0;            // select the input pin for the soil detector
unsigned int sensorValue = 0;  // variable to store the value coming from the soil detector

void setup()
{
  pinMode(13, OUTPUT);
  //Start Serial port
  Serial.begin(9600);        // start serial for output - for testing
}

void loop()
{
  // read the value from the soil detector:
  sensorValue = analogRead(sensorPin);     
  if(sensorValue<400) digitalWrite(13, HIGH);   // set the LED on
  else digitalWrite(13, LOW);   // set the LED on

I want the led just to blink once say 1 second even if the input condition stays the same.. obviously if the input changed >400 then this should reset..

does this make any sense..

please help

david