Introduction: DIY Arduino Simple LED Timer Circuit

About: I am from Missouri and love to create and learn all about electronics!

In this Instructable I am going to show you how you can make a simple timer circuit. To start off this project I got my hands on the Basic Arduino Starter Kit made by Elegoo. Here is a link to get this kit on Amazon LINK. You can also complete this project with parts you may already have but I prefer the kit as it comes with everything you will need and more.


  • Arduino UNO
  • Mini Breadboard
  • Red LED
  • Yellow LED
  • Green LED
  • Blue LED
  • White LED
  • 10k ohm Resistor
  • 5X 1k ohm Resistor
  • USB Programming Cable
  • Several Small Jumper Wires

Step 1: Circuit Setup

To start with our wiring you can visit my Tinkercad Circuit I designed were you can interact with this circuit online and view the wiring needed to complete this circuit. First off insert all 5 of the LED's into the left side of the breadboard making sure that each LED leg gets its own row on the breadboard. Next insert a 1k ohm resistor on each LED cathode connecting them to the ground rail on our breadboard. Now wire each LED anode to its corresponding pin on the Arduino. Red LED to pin 3, yellow LED to pin 4, green LED to pin 5, blue LED to pin 6 and white LED to pin 7. Insert the push button into the middle of the breadboard splitting the legs into the left and right rows. Now insert our 10k ohm resistor into the 5V rail and the breadboard rail connected to our top pin on our push button. Use a jumper wire to connect the same breadboard row to pin 8 on on our Arduino. Then connect the bottom pin on the push button to the ground rail with a jumper wire. For our last component we can insert the piezo buzzer into the breadboard making sure the ground pin is in the ground rail and the positive pin into a empty rail. Then use a jumper wire to connect the positive pin to pin 8 on our Arduino. After all of that is done we just need to connect our power rails on the breadboard to the 5V and ground pin on the Arduino. Once you have all of your wiring done be sure to double and maybe even triple check it with the provided schematic before powering it.

Step 2: Code

Once your wiring is done we can move onto the code. You can download the code from my Tinkercad Circuit or download it from below. Once you have the code open it into the Arduino IDE and make sure to correctly select the board you are uploading to. When everything is ready click upload and wait for it to finish.

Step 3: Final Product

We are now done, to try out your new timer circuit click the push button switch. Once activated every 2 seconds another LED will light up as it counts to 10 seconds. Once the 10 second timer is over the piezo buzzer will beep for 3 seconds while the LED's all flash to let you know your timer is done. The timer circuit can be adjusted to any time you need by adjusting the delay functions in the code. This was a fun project and is a great project for anyone new to Arduino or someone wanting a fun project to try out. If you have any questions leave them down below and I will try my best to help you out.

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