Introduction: 5 Simple Button and Led Projects With Arduino
- What you for Need these 5 Projects.
- An Arduino uno or Clone.
- 3mm 5mm or 10mm Leds any will work and 1 RGB led.
- Some Push Buttons.
- A breadboard.
- Male to Male Jumper Wires.
- Some 10k and 220 Resistors.
- 10 led bar graph or leds will work
Step 1: Push Button and the Serial Monitor.
If you put this code into your Arduino , when you open the serial monitor and push the button it will come up as 1.
int BUTTON1 = 7;
void setup(){
Serial.begin(9600);
pinMode(BUTTON1,INPUT);
}
void loop(){
Serial.println( );
if(digitalRead(BUTTON1) == HIGH)
{ Serial.println("Button1 1");
}else{
Serial.println("Button1 0");
} delay(200);
}
Step 2: 1 Button 1 Led.
int LED = 13;
int BUTTON = 2;
void setup(){
pinMode(LED,OUTPUT);
pinMode(BUTTON,INPUT);
}
void loop(){
if(digitalRead(BUTTON) == HIGH){
digitalWrite(LED,1);
}else{
digitalWrite(LED,0);
}
}
this code will make it so when you push the button the led will light up.
Step 3: 3 Buttons and RGB LED.
this code should make it so when you push one button one color should light up if you push all three buttons it will make a whitish color.
int BUTTON1 = 9; int BUTTON2 = 10; int BUTTON3=11; int BLUE=3; int GREEN=5; int RED=6;</p><p>void setup(){</p><p>pinMode(BUTTON1,INPUT); pinMode(BUTTON2,INPUT); pinMode(BUTTON3,INPUT); pinMode(BLUE,OUTPUT); pinMode(RED,OUTPUT); pinMode(GREEN,OUTPUT); }</p><p>void loop(){ if(digitalRead(BUTTON1) == HIGH){ digitalWrite(BLUE,1); }else{ digitalWrite(BLUE,0); } if(digitalRead(BUTTON2) == HIGH){ digitalWrite(RED,1); }else{ digitalWrite(RED,0); } if(digitalRead(BUTTON3) == HIGH){ digitalWrite(GREEN,1); }else{ digitalWrite(GREEN,0); }</p>
Step 4: Led Pin 13 and Serial Monitor.
int outPin = 13;
void setup(){pinMode(outPin,OUTPUT); Serial.begin(9600); Serial.println("Enter 1 or 0"); } void loop(){ if(Serial.available()>0) { char ch = Serial.read(); if (ch == '1') { digitalWrite(outPin,1); } else if (ch == '0') { digitalWrite(outPin,LOW); }
}
this code will make it so when you go into the serial monitor and type 1 the led on pin 13 will light up then when
you type 0 the led will be off.
Step 5: Random Number Generator With Led Bar Graph.
int LED0 = 2; int LED1 = 3; int LED2 = 4; int LED3 = 5; int LED4 = 6; int LED5 = 7; int LED6 = 8; int LED7 = 9; int LED8 = 10; int LED9 = 11; long randomNumber; void setup() { Serial.begin(9600); Serial.println("Randon Numbernesssssss"); pinMode(LED0, OUTPUT); pinMode(LED1, OUTPUT); pinMode(LED2, OUTPUT); pinMode(LED3, OUTPUT); pinMode(LED4, OUTPUT); pinMode(LED5, OUTPUT); pinMode(LED6, OUTPUT); pinMode(LED7, OUTPUT); pinMode(LED8, OUTPUT); pinMode(LED9, OUTPUT); randomSeed( analogRead(A0) ); } void loop() { randomNumber = random(2,12); Serial.println(randomNumber); digitalWrite(randomNumber,HIGH); delay(40); digitalWrite(randomNumber,LOW); } //This code will make it so when you connect the led or the bar graph to the Arduino it will make random numbers, and the number it makes is the pin number on the Arduino.
11 Comments
Tip 5 months ago on Step 4
You need to put // before the bottom two lines of code:
ALSO, you need one more Right Curly Bracket } at the end, before the instructions at the bottom, or you'll get this error:// this code will make it so when you go into the serial monitor and type 1 the led on pin 13 will light up then when
// you type 0 the led will be off.
exit status 1
expected '}' at end of input
Question 4 years ago on Step 3
I'm having trouble with the code. I keep getting this error message
3_colour_button:6:11: error: expected unqualified-id before '<' token
int RED=6;</p><p>void setup(){</p><p>pinMode(BUTTON1,INPUT);
^
3_colour_button:12:2: error: expected unqualified-id before '<' token
}</p><p>void loop(){
^
exit status 1
expected unqualified-id before '<' token
Any idea how to fix this or what the issue might be?
Answer 3 years ago
I know this post is 9 months old, but this still may help someone even if not the original poster.
Hi, I had this same issue. When I took a moment to look closer at the code I realized that when it was posted some HTML code was added to it.
Remove all instances of </p> and <p> from the code. This fixed the issue for me. I attached an image of the code that compiles.
4 years ago on Step 4
How about if the input im using is arduino laser sensor. When the laser been cut off it will light on the led. And when there is no passing object it will stay off. Can you provide coding for it?
6 years ago
hey what shold happen on
Step 2: 1 Button 1 Led.
7 years ago
Hi. Nice little starter projects. However, I did notice that there is no code to compensate for switch bounce and so sometimes when you press the button, especially on the RGB project you may not get the led to light. This may cause confusion for some first timers.
Reply 7 years ago
There are two ways to fight bouncing: by software (just a few lines of code) and by hardware. The latter is easier: you simply connect electrolytic capacitor in parallel to the button pins with the value of some 1 to 5 microfarad.
7 years ago
if you use INPUT_PULLUP and put your button between an IO and GND, you don't even need the resistor(s) - the arduino in this mode has a built-in resistor to +5V. Because this is the opposite of your pull-DOWN resistor, you then need to watch for the pin to go LOW instead of HIGH.
7 years ago
If you hook it us like in the diagram this won't do anything. You need to connect the yellow wire to pin 2 according to the code. The picture shows it connected to pin 7.
7 years ago
you've added an additional notes in step 1. 10k resistor.
7 years ago
Neat little set of starter projects for absolute beginners, a sort of what's next after blink. Nice. :)