Let’s write simple program, that will turn on and off LED on our Arduino. For our lesson we need: Arduino, one LED diode, USB cable for programming our Arduino, PC with Arduino IDE, download it you can here: https://www.arduino.cc/en/software
![](https://andjey.info/wp-content/uploads/2021/03/arduino-blink-1-1024x486.jpg)
Connect USB cable to Arduino, for connecting LED we will use D13 pin and GND PIN (see Arduino Nano pins here). Positive wire of diode connect to D13, negative wire – to Ground pin as you can see on photo:
![](https://andjey.info/wp-content/uploads/2021/03/arduino-blink-2-1024x486.jpg)
In Arduino IDE create new blank project:
![](https://andjey.info/wp-content/uploads/2021/03/arduino-ide.jpg)
Here You can see two functions: setup() – which run when Arduion power on, and function loop() – which run in cycle all type when arduino is working. Now let’s create our program.
Bewore function start() let’s create two constants – it will be basic configuration of our program. BLINK_PIN defines which pin is used for connecting LED. BLINK_TIME – define time in milliseconds how long our LED will be on and off.
#define BLINK_PIN 13 #define BLINK_TIME 1000
In function setup() configure pin 13 as output pin:
void setup() { pinMode(BLINK_PIN,1); }
Now create function blink_led() – that will turn on and off our LED:
void blink_led() { digitalWrite(BLINK_PIN, 1); delay(BLINK_TIME); digitalWrite(BLINK_PIN, 0); delay(BLINK_TIME); }
Now write function blink_led() in loop() to run our program in cycle all time when Arduino works:
void loop() { blink_led(); }
Full code of program:
#define BLINK_PIN 13 #define BLINK_TIME 300 void blink_led() { digitalWrite(BLINK_PIN, 1); delay(BLINK_TIME); digitalWrite(BLINK_PIN, 0); delay(BLINK_TIME); } void setup() { pinMode(BLINK_PIN,1); } void loop() { blink_led(); }
Now save program and compile it to your Arduino:
![](https://andjey.info/wp-content/uploads/2021/03/arduino-blink-program.jpg)