The entire base of what Arduino is and how it works starts and ends right here –> Check it out before going ahead, also all software downloads and steps are available within the same space!

The most basic version of the code and more details of the entire experiment can be accessed right here!

Aim of this Blinky experiment: Enable the blinking of multiple LEDs simultaneously as well as alternately with a random delay with the following requirements.

  1. Arduino UNO/Genuino board
  2. Two LEDs
  3. 9 volt battery
  4. Male to male wires/connectors
  5. USB dumping cable

Before working on the physical devices, its best if you can take the time to work on an online software simulator which had a virtual library of tools and a programming base.

The connections are as follows:

Negative (Cathode or black side) of 9V battery to GND pin of Arduino.
Positive (Anode or red side) of 9V battery to VCC pin of Arduino.
Anode of LED1 and LED2 to pin 13 and pin 12 respectively. (Note that any set of the digital pins can also be used arbitrarily)
Cathode of LED1 and LED2 shorted and connected to a common GND pin of Arduino.


After successfully running the simulation on the software (See the demonstration of the same on the feature image above), you can make use of the physical devices in the real world and make the similar connections as shown in the simulation diagram above. After making the LED, Arduino and battery connections, it is time to connect the hardware system to a software environment. Connect the USB dumping cable, one end to the Arduino controller and another to the main system or computer.

Fire up your main computer and download the Arduino application. The link for all installation instructions as well as the software is available here —> The downloadable software is open-source, alternatively you can also choose to code online; for now prefer to work on the downloadable software as it is free and easy to use!

Open the software and type in the program below:



The above programs are to enable blinking of two LEDs together (Case 1) and to enable blinking of the LEDs alternately (Case 2)

After you are done with the script, compile the code for any errors and upload the code into the board. To upload the code, make sure that the USB dumping cable is connected from the computer to the board. After successful uploading of code, remove the cable and switch on the Arduino board to notice an output which looks like this:

LED blinking HIGH and LOW together!
LED blinking HIGH and LOW alternately!