IR Sensor Button

This is an easy way to make a infrared sensor button with the Arduino.
This example shows a infrared sensor button with an integrated light. If you touch the surface then the button lights red. Touch the surface again, then the light turns off.

The first image is a design example.

To change the intensity of the Phototransistor (T1) use an another resistor for R4.

D1           IR LD271
D2           LED 500 red
K1           male connector 4pins
R1           10KOhm
R2,R3      100 Ohm
R4           510KOhm
T1           SFH300FA
T2           BC547A

The Arduino Code is very simple:

#define ACTIVATE_VALUE 750  // Change this value for an another distance
#define PRESS_THRESHOLD 250

int SENSOR_VALUE;
byte ON_OFF = 0;

void setup() {      
  Serial.begin(9600); 
  pinMode(2, OUTPUT);
  pinMode(A0, INPUT);
}


void loop() {
  SENSOR_VALUE = analogRead(A0);
  Serial.println(SENSOR_VALUE);
  if (SENSOR_VALUE > ACTIVATE_VALUE) {
    digitalWrite(2, ON_OFF = !ON_OFF); 
    delay(PRESS_THRESHOLD);
  }
  delay(100);
}

The case I have printed out on a 3D-Printer. The top plate is an 31x31x3mm Acryl-Glas. My button is 35x35x20mm big. The distance from the IR-Diod to the acrylplate is ~6mm.

With a sheet of sandpaper I have made the surface of the acrylglas diffuse.

Youtube: www.youtube.com/watch?v=L9-gg7UPTqw