Connect with us

programmable version of a 555 timer?

Discussion in 'General Electronics Discussion' started by sed, Nov 8, 2011.

Scroll to continue with content
  1. sed


    Nov 8, 2011
    Hi all,

    I am a bit of an electronics beginner and I'm hoping someone might be able to help me with a small project I'm working on :).

    I'm trying to find out if there's something along the lines of a programmable 555 timer. Rather than changing out resistors to change the oscillation frequency/pulse duration time I'd like to be able to change that with programming if its possible. Being able to control the number of cycles before shutting off until next activation is also key.

    For example, i'd like to be able send a pulse to the circuit to flash an LED 3 times for .5 seconds each time then stop until the circuit is activated again. If I could store and activate 2 or 3 different settings such as this on the chip it would be great.


  2. OLIVE2222


    Oct 2, 2011
    Hi Dave,

    Welcome to this forum! I find this one:

    It's more a programmable clock with some 555 pinout compatibility.

    maybe others are availables but they probably will not allow you to do thinks link 3 consecutive blinkings.

    To achieve what you want better to go for a small 8 pin microcontroller from Atmel or Microchip (can be PICAXE).

  3. sed


    Nov 8, 2011
    Thanks for the welcome and quick response Oliver :)

    The other part I forgot to mention in my last post that I would like to integrate is the ability to require for example, button A to be held down before button B is pressed to activate the 3 LED pulses. In my head it seems pretty basic but I thought I'd get that out there in case im wrong.

    The programmable timer doesn't appear that it will give me all the functionality/flexibility I need from what i read from that data sheet (1hz to 10hz jump, nothing in between setting wise). It seems like the micro controller might be the way to go.

    I've been browsing mouser's website looking at micro controllers and it is pretty overwhelming to say the least with over 25,000 different chips to choose from. Of the Atmel chips is there any you could you recommend?

    Thanks again for all the help!
  4. OLIVE2222


    Oct 2, 2011
    Hi Dave,

    They are indeed many product on the market !

    Atmel and Microchip made the most popular 8-bit products on amateur level.Both have almost the same possibilities for comparable devices to make it simple.

    Which one is the best is almost a religious affair, so here under some (hoping) neutral guidance to find the right combination.

    The main decision elements are:

    software side

    Atmel offer a free programming environment, AVRSTUDIO and a free C compiler.This set is compatible with all they 8 bits uC familly.

    Microchip offer free programming environment, MPLAB with a free limited C compiler. This set is family depending, each familly as is own compiler.

    Independent compiler are also available, here a range of C, Pascal and Basic compiler for both Atmel and Microchip.

    Here a basic compiler for Atmel (2K code size version is free)

    Here a basic compiler for Microchip

    hardware side

    Olimex made boards for both. They have a wide range of good value for money products. available at Mouser and Farnell

    Futurlec also have few good value for money products.

    and again.

    Programming tools

    both brand offer cheap in situ programming pods and many clones are available on ebay, exemples:

    Popular products

    Arduino is a very popular open source of project based on Atmel product. He combine a programming environment and very flexible harware platform. just google it.

    PICAXE is a popular commercial product based on Microchip uC. It use Basic language in place of C what can make a shorter learning curve. The Basic is included in the chip itself. The code is interpreded not compiled so. Mean that you must bought a new PICAXE chip for each project, not a blank standard one.


    Both brand can offer you almost any componants they will fit your needs. A good choice to start is a uC including all standards peripheral (ADC, PWM...) and an uart to ease the debugging (and programming if you use a bootloader).
    You can narrow down your choise with the ATMEGA8 or 88 for Atmel and PIC16F876 for Microchip.

    Another thinks to take into account it's the guidance and the tools you can find around you.

Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day