led blinking when it is not suppose to be

Projects Programming
1 
#include<CapacitiveSensor.h>
CapacitiveSensor capSensor = CapacitiveSensor(4,2);
const int ledPin = 12;
int threshold = 1000;

void setup() {
  pinMode(ledPin, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  long sensorVal = capSensor.capacitiveSensor(30);
  Serial.println(sensorVal);
  if (sensorVal > threshold) {
    digitalWrite(ledPin, HIGH);
  } else {
    digitalWrite(ledPin, LOW);
  }
  delay(10);
}

I'm practicing coding on the arduino. Currently at beginner project 13: touchy feely lamp.
After setting up the circuit and running the code.
I notice that the led are blinking instead of fully turn on.
The sensorVal is about 200++ when not touch.
By looking at the Serial mornitor, the sensorVal ranges from 200++ to about 2000++ when in contact with the touch. This will cause the led to blink as it ranges between 1000. The led should not be blinking.

May I now what may be the reason for this to happened? I've check all the connections and they are firmly connected.

2

I don't know the reason for your problem but maybe a different threshold for switching it of again could help you for example 400. It would act like a Schmitt-trigger than.

3

Try:

 if (sensorVal > threshold) {
    digitalWrite(ledPin, HIGH);
  }
  else if(sensorVal < threshold - 400)
  {
    digitalWrite(ledPin, LOW);
  }