How to Make an Alarm Clock

About: I love to build inventions and I love to cook. Airplanes and the universe fascinate me. I love to take apart machines to find out how they work. I also build machines at home. I have a youtube channel called...

This alarm clock can set alarms at every hour interval, to set an alarm you need to program the time into the clock. You will need an arduino and above you can see what the clock, will look like. I will provide the code so that you can build this alarm clock very easily.

First we will need to know what parts we need to build the alarm clock.


4 digit 7 segment led display(1)

1K Resistor(4)

100K Resistor(1)





breadboard and arduino I used the arduino uno

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Step 1: Connecting the Components

Follow the schematic to see how to wire up the clock. The transistor collector pin will connect to ground on the arduino. Many transistors will work so you don't really need the exact number. Then, remove pin 4 from the arduino and connect a wire to it. This wire will connect to a 100K resistor then to positive on the buzzer. That buzzers negative side will connect to ground. Next, wire an LED in parallel with the buzzer, the LED does not require a resistor. After you wire everything tape or zip tie the wires so they aren't blocking the display. Plug in your arduino to your laptop to make sure nothing short-circuited. If the arduino powered on corectly you can move on to the next step. If a problem occured please comment and check schematics.

Step 2: Program the Arduino

Download this piece of code and change the time to match your current time in the setup area of the code. Also, change the time the alarm occurs by going to the bottom of the loop. Upload the code and you are done. After you upload the code check if the buzzer worked, if it did the LED will light up as the buzzer sounds. If this project didn't work for you please comment and tell me what's the problem.

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    6 Discussions


    1 year ago

    Hey ExtremeSam, I know this was one year ago but how long do you think this will take to make?


    3 years ago

    do I have to do anything to the code you posted if so let me know what


    1 reply

    Reply 3 years ago

    No, but if the clock is slow or too fast then le me know and I'll update the code


    Nice alarm clock. It would be especially cool if you mounted the parts inside a clear plastic housing so that you could still see all the wires and connectors.

    1 reply