Introduction: On Off LED With 1 Button

I am not good at English...But I will try my best.

Many guys(including me :) try to on and off a LED with 1 push button. But due to some logical error in the IDE, it can not be happened. Sometimes, the LED comes to life when the button is pressed; but immediately becomes off when the button is released. I tried a lot and at last made a solution. In this instructable, you will be able to switch on the LED when the button is pressed once, and switch it off when the button is pressed twice. I will try my best to wxplain the code. Best Of Luck.

Step 1: Components

Arduino Uno

LED

330ohm Resistor

Simple push button

10k Resistor

Jumper wires

Step 2: Wiring

Make the connection as below:

LED + to 330ohm Resistor to Arduino pin 3

LED - to GND

Button(pole1) to Arduino 5v

Button(pole2) to Arduino pin 2

Now ground the button through a 10k Resistor.

Step 3: Coding

Copy the below Code or Download the ino file:

/*
* Programmed by: Md. Mehrab Haque

* Dhaka, Bangladesh.

* Phone: +8801795415378 */

int stateNow = 0;

int stateBefore = 0;

int i = 0;

int j = 0;

void setup() {

pinMode (2, INPUT);

pinMode (3, OUTPUT);

}

void loop() {

stateNow = digitalRead(2);

if (stateNow != stateBefore) {

if (stateNow==HIGH and i==0) {

digitalWrite (3, HIGH);

j=1;

}

else if (stateNow==LOW and j==1) {

i=1;

}

else if (stateNow==HIGH and i==1) {

digitalWrite (3, LOW);

j=0;

}

else if (stateNow==LOW and j==0) {

i=0;

}

}

stateBefore=stateNow;

}

Step 4: Upload the Code and Have Fun !!!

If you can not understand any line of the code, then please comment.....I will solve it in no time.

Comments

author
Md Mehrab Haque (author)2016-06-27

Thanks for your feedback

author

amazing! I wanna learn code but I really like hardware I'm like geeking out right now, just found this site. OMG so cool!

author

I also learned about arduino and robotics from instructables...it is best.

author
DIY Hacks and How Tos (author)2016-06-27

Good intro Arduino tutorial.