Flashing L.E.D. Using 555 Timer




I was trying to put in a video but it didn't work for me, so here is a link to YouTube http://www.youtube.com/watch?v=9rS9nFG8xdI
This is a detailed instruction showing how to build a flashing L.E.D. using 555 Timer.
There is no knowledge of electronics required in order to complete this project.
All the parts needed are listed, priced and links to them are also included. 

There are two sets of pictures, the top shows the progression of the project and the bottom shows each step individually.

This is my first instructable and it is also an assignment so please leave comments.
Thank you.

Step 1: Parts List

Here you will find a list of all required parts, their pictures, prices and where to get them.
There is also an excel file attached.

1. Breadboard
2. 9v Battery
3. Battery clip
4. Jump Wires
5. 555 Timer
6. Capacitor 1μF
7. Resistor   1k Ohm            x 2 (brown, black, red)
8. Resistor    470k Ohm            (yellow, purple, yellow)
9. L.E.D.

Time needed to finish this project: 5 - 10 min.

All the above parts can be bought at http://radionics.rs-online.com/web/ next day delivery (Ireland).

Step 2: 555 Timer Pin - Out and Breadboard Layout

First picture shows a pin-out for the 555 Timer. This will be needed in order to connect the chip.
The second picture shows how the paths in the breadboard are connected.

Step 3: Putting All Together

This project contains small parts which can be ingested or inhaled, so keep away from young children.

Make sure to push all the parts in to the breadboard that they make contact with it.

1. Place the 555 Timer chip in the middle of the breadboard, make sure to put it in the right way round other wise when you will connect the battery the chip will burn.

2. Using short length of jump wire connect Pin 1 (negative) to the bottom row of the breadboard   (ground).

3. Connect Pin 8(positive) to the top row of the breadboard (VCC).

4. Take another length of jump wire and connect Pin 4 with Pin 8.

5. Identify the legs on the capacitor C1, the short one is the negative and the long one is positive. Connect the positive leg to Pin 2 and the negative leg to the ground (GND).

6. Now connect Pin 2 with Pin 6 using piece of jump wire.

7. The resistors can be connected either way round. Using the 470k Ohm (R1) resistor connect Pin 6 with Pin 7.

8. Take the 1k Ohm (R2) resistor and connect Pin 7 to VCC.

9. Connect one end of the second 1k Ohm (R3) resistor with Pin 3 (output) and any empty row on the breadboard (this resistor will be connected with L.E.D. in the next step).

10. Identify the legs on the L.E.D., short one is the negative(-) and the long one is positive(+). Connect the positive leg with the resistor and the negative leg to the GND.

11. The final step is to connect the battery clip, the red lead to the VCC and the black lead to the GND. Connect the 9v battery and enjoy the effect.

18 People Made This Project!


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73 Discussions


Tip 21 days ago

I build this circuit with a 1uF capacitor and it flashed too fast to be seen. A 47uF capacitor was a better choice, since the led flashed with around 3Hz.


4 weeks ago

how to connect 10 leds in this connection?


9 months ago

When I was going through google images I came across this post and noticed the wrong capacitor symbol was used. To help educate you, and those reading this page I have included a link with symbols. There are 2 types of capacitor symbols. Polar and Non-Polar. A polar symbol should have been used. Please use this page as a guide for your future schematics.

SparkFun Schematics

1 reply

Reply 4 months ago

very goood point, man!
in the schematic it should show the polarized (i always think electrolytic) capacitor and then there's no need to 'identify legs' instruction, 'cause whoever uses them *should* know @ least how to 'search-engine' determine polarity of a capacitor.

sorry, i started with on a negative tone...

thanks for the schematic, man! good job.

one suggestion, though...
the legs of the IC r numbered 1-8 kind of sequentially. on the diagram 1 and 5 r next 2 each other. it's kind of okay in general, but for a dummy like me would b nice[er?] 2 show pins in natural order vs this random 1. that would help people with connections... i feel like.


3 years ago

Please I need a circuit that beeps with buzzer, continuous beeping ... Smoogfk@gmail.com. Thanks

1 reply

Reply 5 months ago

just replace led with buzzer


1 year ago

I don't have a 1µF capacitor. Will a 4.7 work?

1 reply

2 years ago

I doing it's don't but i smell not good?

like fire in led.

1 reply

Reply 5 months ago

maybe you're feeding too much of voltages to your led or the chip and thus overheats the chip and makes smoke


2 years ago

does one need a programmer to program a 555chip and also can a 555 chip be programmed using a programmer like arduino ? thanks.

3 replies

Reply 5 months ago

Dear azharko,
555 chip is an analog chip which means it cannot be programmed using a computer


Reply 2 years ago

The 55 chip is a collection of logic gates which allow you to set a cycle of on/off for the output pin. The greatest extent you can use a 555 is to make an LED flash or to add a timing function to a project. Smarter programmable chips like the processor in an arduino have a similar internal structure but are many times more complex.



6 months ago

I've been collecting inexpensive electronic parts from China using Ebay sellers. I've played with Arduino and ESP-8266. This was my first attempt at a circuit using a 555 timer. I followed these instructions and it worked the first time. I tried two LEDs (red and blue) in series and that worked too. I successfully substituted a 510K resistor for the 470K in step 7 because the resistor "assortment" I have didn't include a 470K. A comment here inspired me to try this in Tinkercad. I got it working there too!


1 year ago

Thanks alot! Got it working and blinking!


4 years ago on Introduction

I'm new to electronics, and I tried making this project, but the LED just stays on solid...I've ripped it apart and restarted 10 times now..what am I doing wrong?

1 reply

Reply 1 year ago

I had the "stayed on solid" problem and it turns out that what was supposed to be my 470K resistor was actually much much much less resistance... I read the resistor code wrong. AND so... it looked like it was solid LED light but actually it was just flashing very very very fast. fixed the resistor and it worked. No idea if that is related to your problem.