I am rather new to this and as part of a hobby project I'd like to end up with a simple display showing a time counter. Starting at 0 and going up from there, being able to support several hours (so showing seconds tick by, then minutes and finally hours). So maybe have six 7 segment displays, counting up. This would be powered 'from the wall', after transforming the voltage into the fitting value.

I have seen some circuits that use 7 segment displays along with 555 components to create some sort of timer circuits but they seem quite complex in terms of size and component number.

Is there a way, perhaps using some more advanced/complex components, that I could achieve what I want?

I'd like to avoid overly complex circuits that depend on precisely measured resistors and capacitors to create counters that tick with the rate of seconds.

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    \$\begingroup\$ "Any" microcontroller with a suitable display should do. \$\endgroup\$
    – Dampmaskin
    Commented Apr 20, 2017 at 14:04

1 Answer 1


You can certainly do that with discrete logic, an 555 for the second timer, and discrete 7-segment display drivers.

That will take dozens of components, hours to build, and will have pretty terrible accuracy.

Or, you can buy a cheap microcontroler board (e.g. a small Arduino-compatible board, or anything else), and do it in half an hour.

That will be significantly easier, and add a much more practical skill to your repertoire. Also, it might use far less power (the classical 555 isn't power-efficient at all, and with a microcontroller, you could also easily dim the displays, so that you can save even more power).

Personally, I see the 555 as an excellent example circuit for simple analog oscillation generators, and something that you can wire up at least once in your live to make something blink, or listen to a ca. 1 kHz square wave.

It should be used as an example for simple circuitry, that's all.

There's some legitimate usage, especially when dealing with a simple-to-define behaviour, see Finbarr's comment below, but I'd argue that for applications where you'd need to process your 555's output in a complicated way, a microcontroller will get the job done much much easier, and usually, more cost-effectively.

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    \$\begingroup\$ You say that.... but the fuel pump relay in my car has a 555 inside. It cuts off the fuel supply if it doesn't get regular pulses from the coil to show that the engine is running, e.g. after a collision. \$\endgroup\$
    – Finbarr
    Commented Apr 20, 2017 at 14:26
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    \$\begingroup\$ @Finbarr The world never stops to amaze me! Wow! Yeah, I'll definitely edit my answer to reflect that! \$\endgroup\$ Commented Apr 20, 2017 at 14:29
  • \$\begingroup\$ @Finbarr done :) \$\endgroup\$ Commented Apr 20, 2017 at 14:31
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    \$\begingroup\$ Yup, and I agree this is definitely a job for a micro, with multiplexed displays etc, component count would be minimal and added functionality opportunities are huge. \$\endgroup\$
    – Trevor_G
    Commented Apr 20, 2017 at 14:37
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    \$\begingroup\$ @Trevor … now, only if those parties would have involved actual fun… I see your point. I really want to believe this might have gotten a little better, but I know at least defence folks that really are shocked when they learn that they've been selling devices to customers that they must deliver with an info about which software they use within that device, because, you know, getting some software for free doesn't mean you can act like it's your own... So my fear is that in reality, code releasing might be very complicated still, especially in certain sectors. \$\endgroup\$ Commented Apr 20, 2017 at 15:03

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