555 timer design contest

The 555 Timer IC is an integrated circuit (chip) implementing a variety of timer and multivibrator applications introduced in 1971. The 555 part is still in wide use, thanks to its ease of use, low price and good stability.

555 Contest claims to be biggest, newest, most-independently conceived 555 timer design contest the world has ever seen! The organizers of the contest are interest in seeing new designs and creativity blossom. Now it is time to act because all entries must be submitted by March 1st, 2011. Yeah, it’s quick, but the world moves fast. And remember that “You’ve got 8 pins…and one shot.” So visit http://www.555contest.com/ for more details.



  1. Tomi Engdahl says:

    Implementing A CPU Using 555 Timers And Logic Synthesis

    There is many a comment on these here pages along the lines of “Why did you use a microcontroller, when you could just have easily used a 555 timer!” And, yes, we sometimes agree with the sentiment, but when a chance comment seen by Hackaday.io user [Tim Böscke] suggested turning it around and building a microcontroller out of 555 timers, the gauntlet was well and truly thrown down. Now let’s be clear, this is not the first time we’ve come across this idea, there was a breadboard 555 based build ten years ago, but this is the first time we’ve seen it done by leveraging open source synthesis targeting a PCB!

    The first logic element was a simple inverter, constructed by tying the TRIGger and THReShold pins together.

    From there it was a simple matter of adding a few diode-resistor networks to the input, to effect a NAND2 gate and a NOR2 gate.

    [Tim] has previously created a minimalist CPU called MCPU, with a mere four instructions, designed to fit in a 32 macrocell FPGA, so was able to reuse that design for this project. The fun part was to leverage the PCBFlow toolchain [Tim] maintains, which implements a Yosys synthesis flow with a custom place and route (PnR) backend. A liberty file was produced describing the circuits (macrocells) [Tim] wanted to make use of, then a synthesis script implemented the flow using Yosys/GHDL to elabourate the design, map it into the technology defined earlier, and write out a netlist the PnR tool could use. Helpfully Yosys also writes out a PDF of the design as well as a spice netlist. What a tool!

    The PnR tool [Tim] created for PCBFlow was written in python, and outputs the XML format that Eagle can use.

    555ENabled Microprocessor
    A Microprocesser made in a digital logic family based on the NE555

  2. Tomi Engdahl says:

    All Hail Your New Giant 555 Timer Overlord

    You asked for it, and now you’ve got it. It’s taken more than a decade of accumulated complaining, but this gigantic 555 timer IC has finally gathered enough psychokinetic energy to take corporeal form and demand fealty from the readers of Hackaday.

    Or not. The less exciting explanation is that creator [Rudraksha Vegad] was looking for a way to combine his interests in discrete electronic components and woodworking. The result is an incredible build that’s more than just a conversation starter; this desktop-sized version of the iconic integrated timer circuit is fully functional. You can even hook it up to a breadboard, assuming you’ve got some alligator clips handy.


  3. Tomi Engdahl says:

    ATtiny555 Replaces 555 Timers with a Microcontroller That Simulates 555s
    Why use a timer when a microcontroller will do?

  4. Tomi Engdahl says:

    CD Player Powered 555 Piano Goes Accordion To Plan

    Ah yes, the 555 piano project. Be it the Atari Punk Console, or some other 555 based synthesizer, Hackers just love to hear what the 555 can do when attached to a few passives and a speaker. It’s a sound to behold. But for [Berna], that wasn’t quite enough! Below the break, you can see his creation, called the Acordeonador.


  5. Tomi Engdahl says:

    Dumping Firmware With a 555

    Put aside your FPGAs and high performance oscilloscopes – Here’s a two-chip solution to your reverse engineering needs

  6. Tomi Engdahl says:

    Work The World On A 555

    Over the years the humble 555 timer has been used in so many unexpected places, but there’s a project from [Frank Latos] which we think may be a first. On a piece of stripboard sit a pair of 555s, and instead of the usual passives there are a set of LC circuits. This is no timer, instead it’s a CW (Morse) transmitter for the 80 metre amateur radio band.

    One 555 is configured as a feedback oscillator through a toroidal transformer with a tuned circuit to set the frequency of oscillation. The other takes an inverted input from the oscillator to produce complimentary push-pull outputs from both 555s, which are fed to another transformer that in turn feeds a low-pass filter and thus the antenna.

    Free-running squarewave oscillators of this type are not unusual for the lower HF bands, but we think this is the first 555 design we’ve seen.

    555 Contest: 4MHz (80 meter band) CW Transmitter
    A simple RF transmitter using only (2) LMC555s

  7. Tomi Engdahl says:

    Surprise at what appeared to be a flaw in the design of the NE555 led to an interesting experiment and to the even more interesting history surrounding the #chip and its #designer.
    Read the full article: http://arw.li/6184KcoCO
    #EDN #IndustryNews #Engineering

  8. Tomi Engdahl says:

    Informed Analysis Picks Better 555 Timer To Drive Power MOSFET
    Dec. 4, 2013
    The venerable 555-type timer makes an effective driver for power MOSFETs, but you have to understand the drive situation when selecting the correct variation of the basic timer. This idea shows how the wrong choice led to unreliable operation and failure, and the basic analysis that points to the correct choice.
    Michael Covington

  9. Tomi Engdahl says:

    555 Timer – Timer
    We’ve come full circle. Here’s a timer made up of timers…

  10. Tomi Engdahl says:

    This Magical Potion Rack Uses 555 Timers for Its Effects

    Built by Andy West from element14 Presents, this magical potion display integrates a pair of 555 timer circuits to create some neat effects

  11. Tomi Engdahl says:

    Should’ve Used A 555 — Or 276 Of Them

    When asked to whip up a simple egg timer, most of us could probably come up with a quick design based on the ubiquitous 555 timer. Add a couple of passives around the little eight-pin DIP, put an LED on it to show when time runs out, and maybe even add a pot for variable timing intervals if we’re feeling fancy. Heck, many of us could do it from memory.

    So why exactly did [Jesse Farrell] manage to do essentially the same thing using a whopping 276 555s? Easy — because why not? Originally started as an entry in the latest iteration of our 555 Contest,


  12. Tomi Engdahl says:

    The World’s Largest 555 Timer… Again!

    We’re going back to an old one – the venerable vacuum tube 555 timer. This was a really fun project we took on a while back to try to make a 555 timer out of just vacuum tubes, and while the prototype made at home on the mill was excellent in every sense of the word, we were struggling coming up with a more professional looking version. Well, fear not, our sponsor PCBWay is here! PCBWay hooked me up with some pretty righteous PCBs, so let’s take a look at what they sent and see if we can get the new and improved 555 going.

    If you need tubes, I strongly suggest either 6AU6 or the 6CB6, both work brilliantly. Just search eBay or your local auction site for “6AU6 lot” or “6CB6 lot.”

    The 7-pin sockets can be found on most online retailers like Amazon or AliExpress. Just search for “7 pin tube socket” and look for the ones that are PCB mount.

    All Vaccum Tube 555 Timer

  13. Tomi Engdahl says:

    Secrets of the Control Voltage Pin on a 555 Timer

  14. Tomi Engdahl says:

    Informed Analysis Picks Better 555 Timer To Drive Power MOSFET

    The venerable 555-type timer makes an effective driver for power MOSFETs, but you have to understand the drive situation when selecting the correct variation of the basic timer. This idea shows how the wrong choice led to unreliable operation and failure, and the basic analysis that points to the correct choice.

  15. Tomi Engdahl says:

    LMC555: the world’s smallest 555 timer. The body of this IC in a VSSOP package as shown is 3mm x 3mm. In a DSBGA package, that size drops down to an incredible 1.75mm x 1.75mm!

    Used VSSOP here though because it was easier to get a breakout board for the package (and because it was easier to place and solder by hand)


  16. Tomi Engdahl says:

    How 555 timers Work – The Learning Circuit

    The 555 timer is probably the most common and popular IC to be used in hobby circuits. There are A LOT of projects out there using the 555 in various ways and it’s easy to find schematics to make a project that has already been proven. But rather than just taking plug and playing circuits with the 555 timer, Karen wants to give you the chance to understand the why of what’s happening when you use the 555 timer. In this episode, Karen breaks down what is happening inside the 555 that makes it function. Learn how the inputs interact with the supply voltage to trigger and reset the output high and low. Find out which pins can be used to adjust the threshold at which that change happens.

    The Learning Circuit: 62: How 555 Timers Work

  17. Tomi Engdahl says:

    555 was 50 years old last year!

  18. Tomi Engdahl says:

    Ordinary product with iconic component

    Whenever I take things like this to bits I just kinda expect to see this old Motorola chip inside.
    It’s only now that I’ve realised that it’s as iconic as the classic 555. With the same modular style that allowed it to be used in many different applications. Dating back to 1983 it has a 40 year history at the time of making this video.

    It’s odd to see a chip with a Motorola number being made by companies like ON and Texas Instruments. There are many new and very minimalist dedicated switching chips available, but this one still seems to be in demand.

    It’s also notable that if you need to source a replacement chip for another product, you may find it easier to just buy an in-car 12v to USB converter for its chip.

    The mystery missing diode was a 1N914 or similar.
    It basically serves as a fuse in case someone’s power outlet is wired backward, or they install their battery incorrectly.

    It would create a dead short to blow any upstream fuse, or it would let the smoke out and shut down the circuit protecting the cell phone or other device plugged into it.


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