LED Scroll light help

Thread Starter

Nabeel H

Joined May 7, 2018
3
Hi, I'm kinda new to electronics, I know some basic things and I'm trying to create a scrolling led light bar for a project, the led bar is around half inch by 4 inches long, I want the led to scroll from left to right or right to left like the text ones but no text (not sure what the correct term is). I can manage this with an arduino but I don't have space for it in this project, is there another way to create the circuit board as small as possible? Thanks
 

Bernard

Joined Aug 7, 2008
5,254
How many LED's ?
Something like Knight Rider ?
How much space is available ?
 

dl324

Joined Mar 30, 2015
8,855
Welcome to AAC!
the led bar is around half inch by 4 inches long, I want the led to scroll from left to right or right to left like the text ones but no text
The first thing you need to do is to provide enough information for someone to be able to help you.
  1. How many LEDs?
  2. What are the LED voltage and current specs?
  3. Dot or bar mode?
  4. What determines when to change direction?
  5. How much space is available?
 

AnalogKid

Joined Aug 1, 2013
8,100
The thing that makes a moving text display (called a Times Square display) work is that the letters are different from one another, and your eye and brain track the moving pattern of shapes. Getting a row of identical rectangles to appear to move in one direction is a bit more tricky. Describe the pattern you want to appear to move, and how quickly.

ak
 

xed_over

Joined Feb 5, 2018
19
I can manage this with an arduino but I don't have space for it in this project, is there another way to create the circuit board as small as possible? Thanks
How much space do you have? There are smaller Arduino boards, such as the Nano
 

Thread Starter

Nabeel H

Joined May 7, 2018
3
wow so much activity, so many responses i like this forum.. lets see if I can answer everything I could. I don't have a picture its gonna be 3d printed, the light bar is going to be 0.5"x4" id prefer the board would sit behind it without sticking out.. prob 8-12 leds (undecided how bright i want to go) i prefer bar mode, also a switch would trigger it to turn on and off. I looked at the link "jpanhalt" and I'll be honest I don't understand a damn thing.
 

AnalogKid

Joined Aug 1, 2013
8,100
1. A single row of 8-12 single LEDs (as opposed to a row of clusters).

2. Visible in normal indoor room lighting.

3. If the LEDs are numbered 1-12 from left to right, then the patten is
1
1 2
1 2 3
etc.
1 2 3 4 5 6 7 8 9 10 11 12
1
12
repeat forever

yes / no ?

Options:

4. Outdoor daylight visible

5. Single cycle, non-repeating

What power supply voltages are available?

ak
 

Thread Starter

Nabeel H

Joined May 7, 2018
3
1. A single row of 8-12 single LEDs (as opposed to a row of clusters).

2. Visible in normal indoor room lighting.

3. If the LEDs are numbered 1-12 from left to right, then the patten is
1
1 2
1 2 3
etc.
1 2 3 4 5 6 7 8 9 10 11 12
1
12
repeat forever

yes / no ?

Options:

4. Outdoor daylight visible

5. Single cycle, non-repeating

What power supply voltages are available?

ak
Yes to all it's like you're reading my mind lol, that's exactly the pattern i want except keeps repeating until switched off, power source is a 12v, i know how to setup the leds to the power source with resistors and do the switch if that helps, i just don't know what other parts i need for memory or ic or whatever is needed to make that pattern. Sorry if i'm horrible at explaining I don't know the technical names :)
 

AnalogKid

Joined Aug 1, 2013
8,100
For 12 LEDs, I'd start with two 8-bit shift registers and a clock oscillator. Since some gating might be involved in getting the circuit to reset itself at step 13, I'd use one section of a CD4093 quad NAND gate as the oscillator, leaving three gates for the logic. These parts cannot drive the LEDs directly to any useful brightness, so add two ULN2004 drivers. They are overkill, but cheap and convenient.

ak
 

Bernard

Joined Aug 7, 2008
5,254
I think all can be squeezed in to .5 X 4 in. using dead bug style wiring & 1/8 W resistors.
ICs are .325 in. wide + 2 1/8 W Rs = .479 in. wide.; .765 in. long X 3 = 2.3 in. leaving 1.7 in for Cs & connections. I'd use wire wrap wire.
The .o1 uF C should be C3. Adjust timing with R1 & C1 with time about T= RC or as shown about 1/2 sec / step. Bar Graph 00001.jpg
 

AnalogKid

Joined Aug 1, 2013
8,100
The 74AC164 can source/sink up to 20 mA per output, limited to a total of 100 mA per package. This is much better than a standard CMOS output, but circuit operation is limited to 5 V.

ak
 

128ITSH

Joined Jul 20, 2017
101
The solution depends on what do you want to learn.
If you want to learn about basic logic circuits, go with what AK and Bernard suggested.
If You want to do it in the easy way, use a very small arduino board or an atmega328 with an arduino bootloader.
If you want to start learning embedded programming that is more complex than arduino, use a normal AVR and a programer.
There might be more options, but it's up to you which to choose from.
 

AnalogKid

Joined Aug 1, 2013
8,100
If You want to do it in the easy way, use a very small arduino board
Disagree.

From Wikipedia: The microcontrollers are typically programmed using a dialect of features from the programming languages C and C++.

So it's easy if you already own a development system or programmer, are fluent in C and C++, and know how to configure the multi-purpose I/O ports and pins. Otherwise, not so much.

The LEDs and their resistors are a constant in any approach. Separate from that, the discrete path means soldering 55 pins. My opinion is that that will take less time than figuring out how to load and navigate the development environment and compiler (assuming you got them for free), let alone deciphering the control registers and writing any actual code.

ak
 

dl324

Joined Mar 30, 2015
8,855
People, please read before posting useless information:

From the original post:
I can manage this with an arduino but I don't have space for it in this project,
Post 8:
the light bar is going to be 0.5"x4" id prefer the board would sit behind it without sticking out.. prob 8-12 leds
If You want to do it in the easy way, use a very small arduino board or an atmega328 with an arduino bootloader.
except the OP did already say he could do it with an arduino
Arduino is too big.
 

128ITSH

Joined Jul 20, 2017
101
Disagree.

From Wikipedia: The microcontrollers are typically programmed using a dialect of features from the programming languages C and C++.

So it's easy if you already own a development system or programmer, are fluent in C and C++, and know how to configure the multi-purpose I/O ports and pins. Otherwise, not so much.

The LEDs and their resistors are a constant in any approach. Separate from that, the discrete path means soldering 55 pins. My opinion is that that will take less time than figuring out how to load and navigate the development environment and compiler (assuming you got them for free), let alone deciphering the control registers and writing any actual code.

ak
I said this was the easiest way because the OP said he knows how to program an arduino. He can get a USB to serial board for cheap and program the arduino. But
People, please read before posting useless information:

Arduino is too big.
True about the arduino pro mini which has a width of about 2 inches, but the atmega328p IC with ready bootloader can certainly fit there.
All you need then is a 16Mhz crystal and a USB to serial board. There are tons of tutorials for this.
 
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