Hello everyone!

I'm curious if anyone may be able to help me figure out a component I need for a project I'm putting together.
I need to figure out how to make a system of approx 30 LED lights that blink in a randomized sequence. I also need to figure out if there is a way to limit the intensity of the LED light when it blinks. Finally, I need to figure out if there is a way to control the duration of time in which the individual LED lights up.
Is this something that can be accomplished with a simple chip? A friend told me that this may require a micro controller. I greatly appreciate any insight you all may have!

Thank you!

 

A friend told me that this may require a micro controller. I greatly appreciate any insight you all may have!

I have to agree with your friend on that note. While many interesting LED sequences can be developed using discreet components the use of micro-controllers makes things much more simple and greatly reduces component count. There are also possibilities using a micro-controller along with assorted discreet components. While using a micro-controller does involve some programming skills there are also endless code samples available online to get someone started.

I need to figure out how to make a system of approx 30 LED lights that blink in a randomized sequence. I also need to figure out if there is a way to limit the intensity of the LED light when it blinks. Finally, I need to figure out if there is a way to control the duration of time in which the individual LED lights up.

My opinion runs with that of your friend but driving 30 LEDs individually will be a challenge. One popular approach is the use of RGB (Red, Green, Blue) LEDs where you have three colors in a single package. Blinking is no problem along with timing as well as fade in and fade out (Intensity). What is needed is you sit down with a blank sheet of paper and a pencil (pencil with large eraser helps). Then you visualize what you want including things like LED size and the sequence(s) you want.

You may want to consider any of several micro-controller pre fabricated boards available, for example Arduino or PICAXE to name a few. You can likely find some online videos showing the possibilities with each. Additionally each makes several versions of micro-controllers, simply put the larger the chip (more pins) the more it will do. You will still likely need a few discreet components to drive larger LEDs but that comes later.

Welcopme to the AAC forums....

Ron

 

This is only 10 random LEDs but it's a start if interested- check- YouTube, Jack Barnard fireflies.

 

LEDs, 555s, Flashers, and Light Chasers

 

Honestly, in the time you would need to learn programming skills to pull something like this off, you could wire up 30 555s that would give you at least 200ma per LED and the ability to set the on time of each.

You could also use less 555s and some 4017s with transistors to give a random affect. Placing a cap at the bases can give a fading effect.

 

A friend told me that this may require a micro controller.

I think this would be the easiest route. Wire the LEDs as a 2D matrix. You can control 30-ish LEDs with about a dozen I/O's.

The time required to do a purely hardware or hardware+software solution depends on what you have on hand and your experience.

I could hack together something using a microcontroller in a few hours because I already have code that implements a scrolling display on a single 5x7 LED matrix.

 

It really depends on if you want to spend the time building or just get it going.
Making the hardware for flashing many LEDs can be fun.
Hardware will work well, and in fact I have some Christmas lights I built many years ago that ran 24 LEDs from a 74HC14.
It is still around here somewhere and has given years of service.

But now, but I would go with an Arduino and addressable LEDs myself.
https://www.ebay.com.au/itm/DC-5V-5...465902?hash=item2ccb113e2e:g:K1YAAOSw1NFaJMC8
https://www.ebay.com.au/itm/NEW-UNO...931845&hash=item3f8dddb03e:g:coMAAOSw8oFXz6U9
Then you can control the colours, brightness, and pattern as you want. And do such things as make the brightness dependant on the ambient light. Even sound triggered. Lots of options that will be hard to implement in just hardware.Total price about $20US. (EBAY prices)
That does not include the power supply. But you would have to get that anyway.
If you have not done any programming before, it would be a good project to start with.

A good place to get stuff if you want support, and you live in USA, is Adafruit. They have lots of tutorials that can be a great help.
Here is Oz, the postage is a bit of a killer to get stuff from them.
https://learn.adafruit.com/adafruit-neopixel-uberguide/arduino-library-use
Here is a compromise, soldering and programming
https://www.adafruit.com/product/1938

 

For 30-ish led I would use several Uno or Nano microcontroller boards.

 

Try using an Arduino. 30 Leds is a lot, but there are boards with more outputs and you can also get get shields and extensions.

 

Wow! Thank you for all the detailed responses!
I really appreciate it and I will start doing more research based off or your advice!

Thank you!!

So it sounds like if I wanted to just use 10 lights, it would be a lot easier?

 

Perhaps less work, but not easier per se.

One bit of further advice from me. All pure digital circuits are notorious for having trouble creating truly random numbers/patterns, so try to include something analogue in the design somewhere to help the randomness. Something that changes like a thermistor or such that can be incorporated into the pattern generation stage.

Good luck with writing code to generate random patterns, if it was so easy, WMP wouldn’t play the same songs over and over and over.

 

Perhaps less work, but not easier per se.

One bit of further advice from me. All pure digital circuits are notorious for having trouble creating truly random numbers/patterns, so try to include something analogue in the design somewhere to help the randomness. Something that changes like a thermistor or such that can be incorporated into the pattern generation stage.

Good luck with writing code to generate random patterns, if it was so easy, WMP wouldn’t play the same songs over and over and over.

I'll definitely keep that in mind my friend! Thank you!

 

Yes. I would look into this approach. With an arduino and addressable LEDs you skip over a lot of complexity. The Neopixels strings from adafruit can be driven with 1 arduino pin. You can have as many LEDs as you like. There's tons of sample code out there that you can use right off the bat and then modify as you get comfortable with the code. There are ebay versions of the neopixel stuff for less money than adafruit.

This may step on some toes but I see few reasons to going any other direction if you are controlling more than a small number of RGB LEDs.

It really depends on if you want to spend the time building or just get it going.
Making the hardware for flashing many LEDs can be fun.
Hardware will work well, and in fact I have some Christmas lights I built many years ago that ran 24 LEDs from a 74HC14.
It is still around here somewhere and has given years of service.

But now, but I would go with an Arduino and addressable LEDs myself.
https://www.ebay.com.au/itm/DC-5V-5...465902?hash=item2ccb113e2e:g:K1YAAOSw1NFaJMC8
https://www.ebay.com.au/itm/NEW-UNO...931845&hash=item3f8dddb03e:g:coMAAOSw8oFXz6U9
Then you can control the colours, brightness, and pattern as you want. And do such things as make the brightness dependant on the ambient light. Even sound triggered. Lots of options that will be hard to implement in just hardware.Total price about $20US. (EBAY prices)
That does not include the power supply. But you would have to get that anyway.
If you have not done any programming before, it would be a good project to start with.

A good place to get stuff if you want support, and you live in USA, is Adafruit. They have lots of tutorials that can be a great help.
Here is Oz, the postage is a bit of a killer to get stuff from them.
https://learn.adafruit.com/adafruit-neopixel-uberguide/arduino-library-use
Here is a compromise, soldering and programming
https://www.adafruit.com/product/1938

 

Just so you have a comparison of software vs hardware I'll throw in the drawing for Fireflies In a Bottle as seen on YouTube.