Arduino 10 second timer tutorial

ARDUINO 10 SECOND TIMER TUTORIAL

INTRODUCTION

Arduino is a microcontroller which can be programmed to do certain operations like lighting led, controlling servo, etc. This is a DIY Arduino project intended to simulate a 10 second timer. Timers are used to count down time from a specified value to zero in increments of 1 second. The numbers ‘9’ to ‘0’ are displayed by the LED’s themselves. This is possible by arranging a 3x3 matrix of 9 LED’s where each LED is either switched on or off in order to display the particular number. The codes define which LED should light up and which shouldn’t in order to display the number accurately. The LED’s display numbers from ‘9’ to ‘0’ with a delay of 1 second and hence is the 10 second timer.

COMPONENTS REQUIRED

1. Breadboard or Perforated board

2. Arduino UNO and USB cable

3. 5mm White LED’s (9 nos.)

4. 20 Ohm resistors (9 nos.)

5. Jumpers

6. A 5V DC Power supply

CIRCUIT SCHEMATICS

Figure.1 Arduino 10 second timer schematic

Make the appropriate connections as shown in the schematic above

CODE

This is the code for simulating Arduino 10 second timer. Note that this code is valid only for the particular schematic represented in figure1. The values and choice of ports can always be changed. Copy and paste the code in Arduino IDE sketch area.

void setup() {

  // put your setup code here, to run once:

pinMode (2,OUTPUT);

pinMode (3,OUTPUT);

pinMode (4,OUTPUT);

pinMode (5,OUTPUT);

pinMode (6,OUTPUT);

pinMode (7,OUTPUT);

pinMode (8,OUTPUT);

pinMode (9,OUTPUT);

pinMode (10,OUTPUT);

}

void loop() {

  // put your main code here, to run repeatedly:

//number9

digitalWrite(2, HIGH);

digitalWrite(3, HIGH);

digitalWrite(4, HIGH);

digitalWrite(5, HIGH);

digitalWrite(6, HIGH);

digitalWrite(7, HIGH);

digitalWrite(8, HIGH);

digitalWrite(9, HIGH);

digitalWrite(10, HIGH);

delay(1000);

//number8

digitalWrite(2, HIGH);

digitalWrite(3, HIGH);

digitalWrite(4, HIGH);

digitalWrite(5, HIGH);

digitalWrite(6, HIGH);

digitalWrite(7, HIGH);

digitalWrite(8, HIGH);

digitalWrite(9, HIGH);

digitalWrite(10, HIGH);

delay(1000);

//number7

digitalWrite(2, HIGH);

digitalWrite(3, HIGH);

digitalWrite(4, HIGH);

digitalWrite(5, LOW);

digitalWrite(6, LOW);

digitalWrite(7, HIGH);

digitalWrite(8, LOW);

digitalWrite(9, LOW);

digitalWrite(10, HIGH);

delay(1000);

//number6

digitalWrite(2, HIGH);

digitalWrite(3, LOW);

digitalWrite(4, LOW);

digitalWrite(5, HIGH);

digitalWrite(6, HIGH);

digitalWrite(7, HIGH);

digitalWrite(8, HIGH);

digitalWrite(9, HIGH);

digitalWrite(10, HIGH);

delay(1000);

//number5

digitalWrite(2, HIGH);

digitalWrite(3, HIGH);

digitalWrite(4, HIGH);

digitalWrite(5, HIGH);

digitalWrite(6, HIGH);

digitalWrite(7, HIGH);

digitalWrite(8, HIGH);

digitalWrite(9, HIGH);

digitalWrite(10, HIGH);

delay(1000);

//number4

digitalWrite(2, HIGH);

digitalWrite(3, LOW);

digitalWrite(4, HIGH);

digitalWrite(5, HIGH);

digitalWrite(6, HIGH);

digitalWrite(7, HIGH);

digitalWrite(8, LOW);

digitalWrite(9, LOW);

digitalWrite(10, HIGH);

delay(1000);

//number3

digitalWrite(2, HIGH);

digitalWrite(3, HIGH);

digitalWrite(4, HIGH);

digitalWrite(5, LOW);

digitalWrite(6, HIGH);

digitalWrite(7, HIGH);

digitalWrite(8, HIGH);

digitalWrite(9, HIGH);

digitalWrite(10, HIGH);

delay(1000);

//number2

digitalWrite(2, HIGH);

digitalWrite(3, HIGH);

digitalWrite(4, HIGH);

digitalWrite(5, HIGH);

digitalWrite(6, HIGH);

digitalWrite(7, HIGH);

digitalWrite(8, HIGH);

digitalWrite(9, HIGH);

digitalWrite(10, HIGH);

delay(1000);

//number1

digitalWrite(2, LOW);

digitalWrite(3, LOW);

digitalWrite(4, HIGH);

digitalWrite(5, LOW);

digitalWrite(6, LOW);

digitalWrite(7, HIGH);

digitalWrite(8, LOW);

digitalWrite(9, LOW);

digitalWrite(10, HIGH);

delay(1000);

//number0

digitalWrite(2, HIGH);

digitalWrite(3, HIGH);

digitalWrite(4, HIGH);

digitalWrite(5, HIGH);

digitalWrite(6, LOW);

digitalWrite(7, HIGH);

digitalWrite(8, HIGH);

digitalWrite(9, HIGH);

digitalWrite(10, HIGH);

delay(1000);

}