Need Help with LED controller ideas

Thread Starter

galactimus

Joined Aug 16, 2019
6
First post. Thanks in advance.

I currently have a small LED sign with 8 leds that cycle through the letters on the sign from left to right. I am using a 555 and a 4017 and it has worked great. However I'd like to add a few more details to the sign. Once it cycles through the 8 letters I would like it to flash all the letters on for 2 seconds, then off, then flash them on again for 2 seconds, then off, and then back on for 20 seconds. It will then repeat the entire cycle.

I'm looking for ideas on how to implement this. Thanks
 

AnalogKid

Joined Aug 1, 2013
8,100
With enough counters and gates, any timing sequence is possible. But the more complex the cycle is, the more a uC is a better overall solution. However ...

A $2 uC costs way more than $2 at the start. It needs a software development platform, usually some kind of integrated text editor, syntax checker, and compiler. Next up is a programmer, a device to physically transport the complied program into the target chip. Granted that for many small uCs these are low cost items, and many low-horsepower development sets are free. But if you don't already know C++ and have experience with this setup, the first project can take weeks to debug. If there are more projects in the future, it absolutely is time well spent. If this is a one-off project, then we can get into more counters and state machines.

Back to the current circuit, how long is each LED on?

ak
 

Thread Starter

galactimus

Joined Aug 16, 2019
6
I would like to do this in the simplest most efficient way. If that is a uC that is fine. I have not done any C++ programming in almost 15 years. Lol. There will be other projects where I will need to do similar things as well. I have a GQ-4x4 programmer I use for eproms as well.

Not sure on the exact timing in the current setup. I simply adjusted the size of the resistor until I was happy with the speed. It's under 2 seconds for sure. To me the timing is an aesthetic thing, so those timings if using a uC in this new version may change as I see it up and running with the added sequences.
 

djsfantasi

Joined Apr 11, 2010
5,571
With enough counters and gates, any timing sequence is possible. But the more complex the cycle is, the more a uC is a better overall solution. However ...

A $2 uC costs way more than $2 at the start. It needs a software development platform, usually some kind of integrated text editor, syntax checker, and compiler. Next up is a programmer, a device to physically transport the complied program into the target chip. Granted that for many small uCs these are low cost items, and many low-horsepower development sets are free. But if you don't already know C++ and have experience with this setup, the first project can take weeks to debug. If there are more projects in the future, it absolutely is time well spent. If this is a one-off project, then we can get into more counters and state machines.

Back to the current circuit, how long is each LED on?

ak
@AnalogKid

That was the best explanation I’ve seen here. As a microprocessor bigot, this was a compressive and unbiased explanation.

From the bigots point of view, some of the costs are small, as you say. And in some cases, non-existent!

I’m still anticipating the day I move to a different platform, but the costs to do so are significant. My favorite platform (not necessarily favorite device) is being embraced by several microprocessor manufacturers. That is, all development, testing and programming can be done in the free Arduino IDE. And for some chips, you can use an Arduino to do the programming. Personally, I prefer an inexpensive (less than $20) programmer because the costs and learning curve to wire up a roll your own programmer with an Arduino, is higher than the one time dedicated programmer.

As you say, if you don’t know C (C++ not required), then there is a yuge cost there. So without programming skills, don’t wait until you have a project to learn microprocessors.
 

Thread Starter

galactimus

Joined Aug 16, 2019
6
I should also say that space is a huge issue which will likely make it difficult to use a microcontroller.
 

KeithWalker

Joined Jul 10, 2017
411
I should also say that space is a huge issue which will likely make it difficult to use a microcontroller.
How little space do you have?
This is an Arduino beetle. It is available from AliExpress. You plug it into a USB socket on your computer to program it. All the information, example programs, tutorials and programming tools are availabe on the Arduino web site free of charge.
There is a whole range of different sized Arduino microprocessor boards for just about any application you can think of.
beetle.jpg
 

Thread Starter

galactimus

Joined Aug 16, 2019
6
I am definitely more interested in a microprocessor chip I can install directly to a PCB I design. For space saving and ease of installation into the projects.
 

dendad

Joined Feb 20, 2016
2,979
Ebay has Arduino Nanos from $3.68 AU, that is $2.50 US.
If you are going to do a few, an Arduino Pro Mini (ATMega 328) is cheaper, at $2.90AU, but needs a programming cable,
"FTDI FT232RL USB to Adapter Module USB TO TTL RS232 Arduino 6Pin Cable" for $4.99, but as you just need one, that may be a way to go.
As mentioned above, the IDE is free.
I would not go any other way than an Arduino for your application.
In my industrial control boards, I use a variety of PICs and Beagle Bone Blacks, as well as "dumb" logic boards. But for your application, the Arduino is ideal. There is a great wealth of support on line, and for small runs, or hobbyist applications, it is hard to beat.
The larger controllers are great, but overkill for what you require.
Just note, there are some on this forum who seem to have a religious hatred of Arduino. I have never understood that, but it is so.
The Arduino is not the best system by far, bit it is a really excellent entry point, and that are quite a capable family of boards. My 3D printers are Arduino based, so that is an example of what they can do in the real world. That said, I am toying with upgrading at least on of my machines to an ARM based brain. But it really is not necessary, just it could be a fun project.

EDIT: And there are ARM boards that can be programmed via the Arduino IDE too.
The Arduino IDE is a bit primitive, but it is free, and works quite well. Better ones are available if you want to go that way, and still use Arduino boards.
On a couple of devices I have made, an Arduino Pro Mini or Nano is just another component. It is cheaper than buying the processor, crystal, voltage reg and mics parts. The Arduino is just soldered down like a DIP IC. And they can be socketed if you want.
 
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Thread Starter

galactimus

Joined Aug 16, 2019
6

Hi Dana. I think this option makes a lot of sense for starting out. Gives me a chance to get my project done, learn what I need to, freshen up on my C by looking at the code generated, and ultimately just integrate a microcontroller chip into my pcb design using the code made using the Arduino and software. I would love more info on using the code generated while building with the arduino and writing it to a chip like the ATTiny or others.
 

danadak

Joined Mar 10, 2018
3,570
There are several block languages, all with common elements and all
with their own specific characteristics. I am still trying to wrap my head
around all of them.

Ardublock Can integrate directly into Arduino IDE
mBlock Two versions, seems like second most active version next to Scratch
Snap4Arduino (S4A) Tethered designs to PC, great text to speech capability (talking instrumentation....)
Flowcode Pricey (unlike the rest free), more HW control it seems
Scratchx Arduino version of Scratch, most active of all languages

Some use standard Arduino IDE firmata, others their own. If your part does not connect
in the above chosen IDE you open up Arduino, pick example project, Firmata, then "Standard
Firmata" (except ones that use their own like S4A), program board, then attempt connect to board from
block language IDE you want to use.

Some have parallel capability (think RTOS like behavior). Some have additional
libraries you can choose to import for additional capability.

To program ATTINY you use either an Arduino board configed as "Arduino as ISP" or a
USBASP (ebay sellers).

All have a variety of videos on net, youtube.

May seem like a mishmash of solutions, its evolving, but good news is if you learn one
they are all similar such that adapting to a better newer one not a Everest climb. Scratch
probably the widest used of all, especially grade schools and above.

Some have menu systems a little freaky to navigate......patience and a willingness to
explore will reward you for those.

I started with Ardublock and as I discovered more offerings out there found myself
using different versions for different solutions depending on design goals.

mBlock has two version. 3.something and 5.01, 3 seems more Arduino block
choices, but 5 a little easier to use....

Some more links over here -

https://forum.allaboutcircuits.com/threads/recommend-me-a-microcontroller-dev-board.160538/page-3#post-1402777

Regards, Dana.
 
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dendad

Joined Feb 20, 2016
2,979
Sorry...couldn't resist...

View attachment 184181
I could not resist either...
The best Ebay price of the 74LS154 I could find is twice the Arduino Uno, and 3 times the Nano.
That is not counting the other parts.

And the Arduino is WAY easier to change the operation. It would be so easy to make it's operation light dependent, or even temperature or time dependent.
Not so easy with discrete hardware.
I have made controllers both ways, and now I have very few that are not processor based. I think my last water cannon driver had no processor because that is what my customer wanted, and true to form, after I had built and sold quite a few (and have a stack on stock, now obsolete), he changed his mind about an operational requirement, so a new design was needed. If it had a processor, most of the change could have been firmware!
 
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