Arduino: scan codes from a remote control

There are different types of infrared remote controls produced by different companies: for TV, DVD and other consumer electronics. As well all of them can be reused for Arduino using an infrared sensor.

Infrared sensor

Arduino Uno

Samsung remote control

Different remote controls may have different sets of codes, so first you need to determine what code is sent by each button. It is simple. Just connect IR sensor with Arduino:

Run this program:

#include <IRremote.h>

const int IR_PIN = 10;

IRrecv irrecv(IR_PIN);

decode_results results;

void setup() {
  Serial.begin(9600);  
  irrecv.enableIRIn();
}

char chars[9] = {};

void loop() {
  if (irrecv.decode(&results)) {
    Serial.println(results.value, HEX);
    irrecv.resume();
  }
  delay(100);
}

_{*It uses IRremote library.}

Open serial monitor, press some buttons on the remote control and see the output:

Program prints codes for pressed buttons. For example, a remote control from the Samsung SmartTV sends these codes for numeric buttons:

• E0E020DF 1
• E0E0A05F 2
• E0E0609F 3
• E0E010EF 4
• E0E0906F 5
• E0E050AF 6
• E0E030CF 7
• E0E0B04F 8
• E0E0708F 9
• E0E08877 0

Arduino: print sensor value on the LED display

It is pretty simple to print a value from an analog sensor on the LED display.

For example from a light sensor like here:

and when the sensor is out of light:

Electronic components from the scheme above:

Arduino Nano

Led display MAX7219

Light sensor

LED display is connected with Arduino via these 5 pins:

• DIN - data in
• CS - chip select
• CLK - clock pulse source
• GND
• 5 V

DIN, CS and CLK are connected with Arduino via digital pins 7, 6 and 5.

Light sensor has 3 pins:

• GND
• 5V
• Signal

where signal pin is connected with Arduino via the analog pin №1.

This program reads values from the sensor 10 times per second and displays the averaged result:

#include <LedControl.h>

const int DIN_PIN = 7;
const int CS_PIN = 6;
const int CLK_PIN = 5;

const int SENSOR_PIN = 1;

LedControl display = LedControl(DIN_PIN, CLK_PIN, CS_PIN);

void setup() {
  display.clearDisplay(0);
  display.shutdown(0, false);
  display.setIntensity(0, 10);
}

void displayNumber(int number) {
  display.clearDisplay(0);
  for (int i = 0; i < 8; i++) {
    int digit = number % 10;
    number /= 10;
    display.setDigit(0, i, digit, false);
    if (number == 0) {
      break;
    }
  }
}

void loop() {
  int value = 0;
  for (int i = 0; i < 10; i++) {
    value += analogRead(SENSOR_PIN);
    delay(100);
  }
  value /= 10;

  displayNumber(value);
}