// import the library (must be located in the
// Arduino/libraries directory)
#include <CapacitiveSensor.h>
// create an instance of the library
// pin 4 sends electrical energy
// pin 2 senses senses a change
CapacitiveSensor capSensor = CapacitiveSensor(4,2);
// threshold for turning the lamp on
int threshold = 1000;
#define LED 9 // the pin for the LED
int val = 0; // stores the state of the input pin
int old_val = 0; // stores the previous value of "val"
int state = 0; // 0 = LED off while 1 = LED on
int brightness = 128; // Stores the brightness value
unsigned long startTime = 0; // when did we begin pressing?
void setup() {
// open a serial connection
Serial.begin(9600);
pinMode(LED, OUTPUT); // tell Arduino LED is an output
}
void loop() {
// store the value reported by the sensor in a variable
long sensorValue = capSensor.capacitiveSensor(30);
// print out the sensor value
Serial.println(sensorValue);
// if the value is greater than the threshold, 'button' is down
val = (sensorValue > threshold);
// check if there was a transition
if ((val == HIGH) && (old_val == LOW)) {
state = 1 - state; // change the state from off to on
// or vice-versa
startTime = millis(); // millis() is the Arduino clock
// it returns how many milliseconds
// have passed since the board has
// been reset.
// (this line remembers when the button
// was last pressed)
delay(10);
}
// check whether the button is being held down
if ((val == HIGH) && (old_val == HIGH)) {
// If the button is held for more than 500ms.
if (state == 1 && (millis() - startTime) > 500) {
brightness++; // increment brightness by 1
delay(10); // delay to avoid brightness going
// up too fast
if (brightness > 255) { // 255 is the max brightness
brightness = 0; // if we go over 255
// let’s go back to 0
}
}
}
old_val = val; // val is now old, let’s store it
if (state == 1) {
analogWrite(LED, brightness); // turn LED ON at the // current brightness level
}
else {
analogWrite(LED, 0); // turn LED OFF
}
}