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Basic LED display project help needed

Dave001

New Member
Hey new guys here, have an LED display project I need help with.

So I have a panel with rows of LEDs that correspond to each room, when a call is sent from a room the corresponding LED is illuminated.
I want to take the power going to the LED and instead have it light up a large 2 digit numeric display LED that will show which room number the call is coming from.

I only have basic soldering and electronics skills, so I want to keep it as simple as possible.
I would guess there is some kind of module/ chip that has a bunch of input channels (for each LED, 12 total) which when triggered with a input voltage would illuminate a programed number?...

Huge thanks in advance!!
 

danadak

Well-Known Member
Most Helpful Member
How many rooms ?

The way you are approaching this is you will need a wire coming from each LED
to a Arduino or processor, which scans leds and converts the one found to a numeric.

I assume you can have more than one room active at a time ?


Regards, Dana.
 

Dave001

New Member
How many rooms ?

The way you are approaching this is you will need a wire coming from each LED
to a Arduino or processor, which scans leds and converts the one found to a numeric.

I assume you can have more than one room active at a time ?


Regards, Dana.
12 rooms so 12 LED total.

I was thinking to take the power going to the LEDs and divert it straight into whatever circuit board / module I will be using, so that when it receives the 12v power from LED #1 into channel #1 on the circuit board / module it will convert that into displaying 1 on the digital display.

Yes you can have more than one room active at a time. Thanks for bringing that up! I didnt think about that.
I dont know how to work around that either.

Thanks for your feedback!
 

rjenkinsgb

Well-Known Member
Most Helpful Member
A multiplexer connected to a counter with the digital LED display??
If it "sees" an input it enables the display and switches the counter to a rather slower clock.

That should display any active call number(s) but quickly skip inactive ones so there were no excess delays

With no input it would be continuously counting at the fast rate (eg 20 - 50 steps per second) but if any input is active, switch the count rate to around 1 - 2Hz so each number is clearly visible.

Probably about eight 4000 series ICs to build it; a couple of dual counters, a couple of 8:1 multiplexers, two 7 segment decoders and a few gates for the osc and switching.
 

Pommie

Well-Known Member
Most Helpful Member
What should happen if several rooms all call in close succession? Should it display the first one and remember the other ones? How do you cancel a call? Do you have direct access to the wires from the push buttons?

Mike.
 

danadak

Well-Known Member
Most Helpful Member
12 rooms so 12 LED total.

I was thinking to take the power going to the LEDs and divert it straight into whatever circuit board / module I will be using, so that when it receives the 12v power from LED #1 into channel #1 on the circuit board / module it will convert that into displaying 1 on the digital display.

Yes you can have more than one room active at a time. Thanks for bringing that up! I didnt think about that.
I dont know how to work around that either.

Thanks for your feedback!

Do a scrolling display like a marching stock price ticker display on the financial channels.
Say you plan on 4 rooms displayed at any one moment, separated by a blank digit, so a
12 - 16 digit display would make sense. Or smaller if 2 rooms at a time displayed, 6 - 8
digits.....

This can be done in one part (display external of course) but requires C programming.
Or could do it in block programming using Nano board possibly -

1665485150898.png


Or one of these boards (like 2560) to get more I/O


Block programming, kids using in class for robot programming. Like mBlock,
Scratch for Arduino, Flow Code......

Here is example of what it took to turn on LED when a button is pushed using mBlock :

1665486113896.png



mBlock takes your block design and generates code to program the board.
So you drag and drop blocks onto design canvass, right hand window, configure
them, choose poins, etc... and mBlock will then generate the code to be programmed
into Arduino. Lots of fun.

An example doing display. https://www.electronicssimplified.in/feed/7-segment-display-with-mblock/


Regards, Dana.
 
Last edited:

Dave001

New Member
A multiplexer connected to a counter with the digital LED display??
If it "sees" an input it enables the display and switches the counter to a rather slower clock.

That should display any active call number(s) but quickly skip inactive ones so there were no excess delays

With no input it would be continuously counting at the fast rate (eg 20 - 50 steps per second) but if any input is active, switch the count rate to around 1 - 2Hz so each number is clearly visible.

Probably about eight 4000 series ICs to build it; a couple of dual counters, a couple of 8:1 multiplexers, two 7 segment decoders and a few gates for the osc and switching.
Honestly that sounds way to complicated for me, and I wouldnt be able to troubleshoot it if anything.

But it does sound like something that would work.
So if there is no triggered input, what would the display show? will it be blank or flashing something?
 

granddad

Well-Known Member
Most Helpful Member
:D Back in my day there was a wire pull system ran from each room ( the masters rooms ) back to the butlers pantry. it shook and rang a bell , later it was electrified with buttons and relays .. I would have to rush to the room " You rang my Lord " :D
calling.jpg
 

Dave001

New Member
What should happen if several rooms all call in close succession? Should it display the first one and remember the other ones? How do you cancel a call? Do you have direct access to the wires from the push buttons?

Mike.

Either the first room call/ input and have it show that number until the call is turned off and then show the next called room, or have the display alternate the rooms called every few seconds.

Yes I do have direct access to the push button wires, the all go to the panel that has the LEDs.
 

Dave001

New Member
Do a scrolling display like a marching stock price ticker display on the financial channels.
Say you plan on 4 rooms displayed at any one moment, separated by a blank digit, so a
12 - 16 digit display would make sense. Or smaller if 2 rooms at a time displayed, 6 - 8
digits.....

This can be done in one part (display external of course) but requires C programming.
Or could do it in block programming using Nano board possibly -

View attachment 138905

Or one of these boards (like 2560) to get more I/O


Block programming, kids using in class for robot programming. Like mBlock,
Scratch for Arduino, Flow Code......

Here is example of what it took to turn on LED when a button is pushed using mBlock :

View attachment 138907


mBlock takes your block design and generates code to program the board.
So you drag and drop blocks onto design canvass, right hand window, configure
them, choose poins, etc... and mBlock will then generate the code to be programmed
into Arduino. Lots of fun.

An example doing display. https://www.electronicssimplified.in/feed/7-segment-display-with-mblock/


Regards, Dana.

I like this idea the most so far. But I want to use a display that has 3" - 3.5" size letters so they would be easy to see. So if I was to do a scrolling display it would get into the too big territory. I want to keep the display size to 2 digits.
For the case when more than one room calls, would it be possible to make it:
- Show the first room call/ input and have it show that number until the call is turned off and then show the next called room
- or have the display alternate every few seconds all the rooms called.

Thanks!
 

Ian Rogers

User Extraordinaire
Forum Supporter
Most Helpful Member
This one seems fairly easy to do.
How would it handle when more than one room is called?
It wouldn't... I though you wanted a "basic" system.... I would do it with a pic..
 

danadak

Well-Known Member
Most Helpful Member
I like this idea the most so far. But I want to use a display that has 3" - 3.5" size letters so they would be easy to see. So if I was to do a scrolling display it would get into the too big territory. I want to keep the display size to 2 digits.
For the case when more than one room calls, would it be possible to make it:
- Show the first room call/ input and have it show that number until the call is turned off and then show the next called room
- or have the display alternate every few seconds all the rooms called.

Thanks!

Yes to both.


Regards, Dana,
 

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